Oracle® TimesTen In-Memory Database Replication Guide 11g Release 2 (11.2.2) E21635-11 |
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Oracle Clusterware monitors and controls applications to provide high availability. The following sections describe how to use Oracle Clusterware to manage availability for a TimesTen active standby pair:
Note:
For more information about Oracle Clusterware, see Oracle Clusterware Administration and Deployment Guide in the Oracle Database documentation.Use Oracle Clusterware to manage only the following configurations:
Active standby pair with or without read-only subscribers
Active standby pair (with or without read-only subscribers) with AWT cache groups, read-only cache groups, and global cache groups
Figure 8-1 shows an active standby pair with one read-only subscriber in the same local network. The active database, the standby database and the read-only subscriber are on different nodes. There are two nodes that are not part of the active standby pair that are also running TimesTen. An application updates the active database. An application reads from the standby and the subscriber. All of the nodes are connected to shared storage.
Figure 8-1 Active standby pair with one subscriber
You can use Oracle Clusterware to start, monitor, and automatically fail over TimesTen databases and applications in response to node failures and other events. See "Clusterware management" and "Recovering from failures" for details.
Oracle Clusterware can be implemented at two levels of availability for TimesTen.
The basic level of availability manages two master nodes and up to 127 read-only subscriber nodes in the cluster. The active standby pair is defined with local host names or IP addresses. If both master nodes fail, user intervention is necessary to migrate the active standby scheme to new hosts. When both master nodes fail, Oracle Clusterware notifies the user.
The advanced level of availability uses virtual IP addresses for the active, standby, and read-only subscriber databases. Extra nodes can be included in the cluster that are not part of the initial active standby pair. If a failure occurs, the use of virtual IP addresses enables one of the extra nodes to take on the role of a failed node automatically.
Note:
If your applications connect to TimesTen in a client/server configuration, automatic client failover enables the client to reconnect automatically to the master database with the active role after a failure. See "Using automatic client failover for an active standby pair" and "TTC_FailoverPortRange" in the Oracle TimesTen In-Memory Database Reference.The ttCWAdmin
utility is used to administer TimesTen active standby pairs in a cluster that is managed by Oracle Clusterware. The configuration for each active standby pair is manually created in an initialization file called cluster.oracle.ini
. The information in this file is used to create Oracle Clusterware resources. Resources are used to manage the TimesTen daemon, TimesTen databases, TimesTen processes, user applications, and virtual IP addresses. You can run the ttCWAdmin
utility from any host in the cluster, as long as the cluster.oracle.ini
file is reachable and readable from this host. For more information about the ttCWAdmin
utility, see "ttCWAdmin" in Oracle TimesTen In-Memory Database Reference. For more information about the cluster.oracle.ini
file, see "Configuring Oracle Clusterware management with the cluster.oracle.ini file".
See "ttCWAdmin" in Oracle TimesTen In-Memory Database Reference for information about the privileges required to run ttCWAdmin
commands.
TimesTen does not support Clusterware on Windows platforms.
TimesTen supports Oracle Clusterware releases 11.2.0.2 and 11.2.0.3 with TimesTen active standby pair replication. See Oracle Clusterware Administration and Deployment Guide for network and storage requirements and information about Oracle Clusterware configuration files.
Oracle Clusterware and TimesTen should be installed in the same location on all nodes. The TimesTen instance administrator must belong to the same UNIX primary group as the Oracle Clusterware installation owner.
Note:
The/tmp
directory contains essential TimesTen Oracle Clusterware directories. Their names have the prefix crsTT
. Do not delete them.All hosts should use Network Time Protocol (NTP) or a similar system so that clocks on the hosts remain within 250 milliseconds of each other. When adjusting the system clocks on any nodes to be synchronized with each other, do not set any clock backward in time.
When you use Oracle Clusterware with TimesTen, the active standby pair replication scheme is created on the active master with the ttCWAdmin -create
command and dropped with the ttCWAdmin -drop
command. In between the ttCWAdmin -create
and ttCWAdmin -drop
commands, you cannot execute any of the following commands or SQL statements. However, you can perform these commands or SQL statements when you use the ttCWAdmin -beginAlterSchema
and the ttCWAdmin -endAlterSchema
commands, as described in "Changing the schema".
Creating, altering, or dropping the active standby pair with the CREATE ACTIVE STANDBY PAIR
, ALTER ACTIVE STANDBY PAIR
, and DROP ACTIVE STANDBY PAIR
SQL statements.
Starting or stopping the replication agent with either the -repStart
and -repStop
options of the ttAdmin
utility or the ttRepStart
or ttRepStop
built-in procedures.
Starting or stopping the cache agent after the active standby pair has been created with either the -cacheStart
and -cacheStop
options of the ttAdmin
utility or the ttCacheStart
and ttCacheStop
built-in procedures.
Duplicating the database with the -duplicate
option of the ttRepAdmin
utility.
Executing any built-in procedures for managing a cache grid when the active standby pair in a cluster is a member of a grid.
In addition, do not call ttDaemonAdmin -stop
before calling ttCWAdmin -shutdown
.
The TimesTen integration with Oracle Clusterware accomplishes these operations with the ttCWAdmin
utility and the attributes specified in the cluster.oracle.ini
file.
For more information about the built-ins and utilities, see Oracle TimesTen In-Memory Database Reference. For more information about the SQL statements, see Oracle TimesTen In-Memory Database SQL Reference.
The information in the cluster.oracle.ini
file is used to create Oracle Clusterware resources that manage TimesTen databases, TimesTen processes, user applications, and virtual IP addresses. Create an initialization file called cluster.oracle.ini
as a text file.
Note:
See Appendix A, "TimesTen Configuration Attributes for Oracle Clusterware" for details on all of the attributes that can be used in thecluster.oracle.ini
file.The ttCWAdmin -create
command reads this file for configuration information, so the location of the text file must be reachable and readable by ttCWAdmin
. The ttCWAdmin
utility is used to administer TimesTen active standby pairs in a cluster that is managed by Oracle Clusterware.
It is recommended that you place this file in the TimesTen daemon home directory on the host for the active database. However, you can place this file in any directory or shared drive on the same host as where you run the ttCWAdmin -create
command.
The default location for this file is in the install_dir
/info
directory. If you place this file in another location, identify the path of the location with the -ttclusterini
option.
The entry name in the cluster.oracle.ini
file must be the same as an existing system DSN in the sys.odbc.ini
file. For example, [basicDSN]
is the entry name in the cluster.oracle.ini
file described in "Configuring basic availability". [basicDSN]
must also be the DataStore
and Data Source Name
data store attributes in the sys.odbc.ini
files on each host. For example, the sys.odbc.ini
file for the basicDSN
DSN on host1
might be:
[basicDSN] DataStore=/path1/basicDSN LogDir=/path1/log DatabaseCharacterSet=AL32UTF8 ConnectionCharacterSet=AL32UTF8
The sys.odbc.ini
file for basicDSN
on host2
can have a different path, but all other attributes should be the same:
[basicDSN] DataStore=/path2/basicDSN LogDir=/path2/log DatabaseCharacterSet=AL32UTF8 ConnectionCharacterSet=AL32UTF8
The following sections demonstrate sample configurations of the cluster.oracle.ini
file:
This example shows an active standby pair with no subscribers. The host for the active database is the first MasterHost
defined (host1
) and the standby database is the second MasterHost
in the list (host2
). Each host in the list is delimited by commas. You can include spaces for readability, if desired.
[basicDSN] MasterHosts=host1,host2
The following is an example of a cluster.oracle.ini
file for an active standby pair with one subscriber on host3
:
[basicSubscriberDSN] MasterHosts=host1,host2 SubscriberHosts=host3
Advanced availability involves configuring spare master or subscriber hosts that are idle until needed to replace master or subscriber hosts (used in the active standby pair replication scheme) that either shut down unexpectedly or experience an unrecoverable error.
As mentioned in "Configuring basic availability", the MasterHosts
attribute in the cluster.oracle.ini
file configures the hosts that are used as the master nodes. For an active standby pair replication scheme, you only need two master hosts. In the event of a failure, the host that did not fail becomes the active database (if not already the active database) and the failed host is recovered and becomes the standby master. However, if the failed host cannot be recovered and if you specified more than two hosts as master hosts in the cluster.oracle.ini
file, then the next master host in the list can be instantiated to take the place of an unrecoverable master host.
For example, the following shows a configuration of several master hosts. The first two master hosts (host1
and host2
) are used for the active and standby masters; the latter two master hosts (host3
and host4
) can be used to take the place of either host1
or host2
if either encounter an unrecoverable failure.
MasterHosts=host1,host2,host3,host4
When you configure more than two multiple hosts, you should also configure two virtual IP (VIP) addresses used only by Oracle Clusterware resources that manage TimesTen resources. With these VIP addresses, TimesTen internal processes (those that manage replication) are isolated from any master host changes that may occur because of an unrecoverable host error.
Note:
The Oracle Clusterware resource that manage these VIP addresses (used in advanced availability) are created with thettCWAdmin -createVIPs
command, as described in "Create the Oracle Clusterware resources to manage virtual IP addresses".These VIP addresses must be different from any other VIP addresses defined for Oracle Clusterware use or any VIP addresses that are to be used by user applications. Furthermore, if an application does use these VIP addresses, then the application may encounter errors when a master host fails (either recoverable or unrecoverable). These VIP addresses cannot be used by a user application as a method for client failover or as a method to isolate themselves if an active database and standby master switch.
Specify two VIP addresses in the MasterVIP
parameter, one for each master host in the active standby pair replication scheme. The VIP addresses specified for the TimesTen cluster must be different from any VIP addresses already defined and used by Oracle Clusterware. In particular, the VIP addresses that are created during the Oracle Clusterware install cannot be used with TimesTen.
MasterVIP=192.168.1.1, 192.168.1.2
The following parameters are also associated with advanced availability in the cluster.oracle.ini
file:
SubscriberHosts
, similar to MasterHosts
lists the host names that can contain subscriber databases.
SubscriberVIP
, similar to MasterVIP
, provides VIP addresses that can be used by TimesTen internally to manage a subscriber node.
VIPInterface
is the name of the public network adaptor.
VIPNetMask
defines the netmask of the virtual IP addresses.
In the following example, the hosts for the active database and the standby database are host1
and host2
. The hosts available for instantiation in case of an unrecoverable error are host3
and host4
. There are no subscriber nodes. VIPInterface
is the name of the public network adaptor. VIPNetMask
defines the netmask of the virtual IP addresses.
[advancedDSN] MasterHosts=host1,host2,host3,host4 MasterVIP=192.168.1.1, 192.168.1.2 VIPInterface=eth0 VIPNetMask=255.255.255.0
The following example configures a single subscriber on host4
. There is one extra host defined in SubscriberHosts
that can be used for failover of the master databases and one extra node that can be used for failover of the subscriber database. MasterVIP
and SubscriberVIP
specify the virtual IP addresses defined for the master and subscriber hosts.
[advancedSubscriberDSN] MasterHosts=host1,host2,host3 SubscriberHosts=host4,host5 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0
Ensure that the extra master nodes:
Have TimesTen installed
Have the direct-linked application installed if this is part of the configuration. See "Implementing application failover".
If the active standby pair replicates one or more AWT or read-only cache groups, set the CacheConnect
attribute to y
.
This example specifies an active standby pair with one subscriber in an advanced availability configuration. The active standby pair replicates one or more cache groups.
[advancedCacheDSN] MasterHosts=host1,host2,host3 SubscriberHosts=host4, host5 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0 CacheConnect=y
If the active standby pair is a member of a cache grid, assign port numbers for the active and standby databases by setting the GridPort
attribute.
This example specifies an active standby pair with no subscribers in an advanced availability configuration. The active standby pair is a member of a cache grid.
[advancedGridDSN] MasterHosts=host1,host2,host3 MasterVIP=192.168.1.1, 192.168.1.2 VIPInterface=eth0 VIPNetMask=255.255.255.0 CacheConnect=y GridPort=16101, 16102
For more information about using Oracle Clusterware with a cache grid, see "Using Oracle Clusterware with a TimesTen cache grid".
TimesTen integration with Oracle Clusterware can facilitate the failover of a TimesTen application that is linked to any of the databases in the active standby pair. TimesTen can manage both direct-linked and client/server applications that are on the same host as Oracle Clusterware and TimesTen.
The required attributes in the cluster.oracle.ini
file for failing over a TimesTen application are as follows:
AppName
- Name of the application to be managed by Oracle Clusterware
AppStartCmd
- Command line for starting the application
AppStopCmd
- Command line for stopping the application
AppCheckCmd
- Command line for executing an application that checks the status of the application specified by AppName
AppType
- Determines the database to which the application is linked. The possible values are Active
, Standby
, DualMaster
, Subscriber (all)
and Subscriber
[
index
]
.
There are also several optional attributes that you can configure, such as AppFailureThreshold
, DatabaseFailoverDelay
, and AppScriptTimeout
. All optional attributes (and their default values) are listed and described in Table A-3, "Optional attributes".
The TimesTen application monitor process uses the user-supplied script or program specified by AppCheckCmd
to monitor the application. The script that checks the status of the application must be written to return 0
for success and a nonzero number for failure. When Oracle Clusterware detects a nonzero value, it takes action to recover the failed application.
This example shows advanced availability configured for an active standby pair with with no subscribers. The reader
application is an application that queries the data in the standby database. AppStartCmd
, AppStopCmd
and AppCheckCmd
can include arguments such as start
, stop
and check
commands.
Note:
Do not use quotes in the values forAppStartCmd
, AppStopCmd
and AppCheckCmd
.[appDSN] MasterHosts=host1,host2,host3,host4 MasterVIP=192.168.1.1, 192.168.1.2 VIPInterface=eth0 VIPNetMask=255.255.255.0 AppName=reader AppType=Standby AppStartCmd=/mycluster/reader/app_start.sh start AppStopCmd=/mycluster/reader/app_stop.sh stop AppCheckCmd=/mycluster/reader/app_check.sh check
You can configure failover for more than one application. Use AppName
to name the application and provide values for AppType
, AppStartCmd
, AppStopCmd
and AppCheckCmd
immediately following the AppName
attribute. You can include blank lines for readability. For example:
[app2DSN] MasterHosts=host1,host2,host3,host4 MasterVIP=192.168.1.1, 192.168.1.2 VIPInterface=eth0 VIPNetMask=255.255.255.0 AppName=reader AppType=Standby AppStartCmd=/mycluster/reader/app_start.sh AppStopCmd=/mycluster/reader/app_stop.sh AppCheckCmd=/mycluster/reader/app_check.sh AppName=update AppType=Active AppStartCmd=/mycluster/update/app2_start.sh AppStopCmd=/mycluster/update/app2_stop.sh AppCheckCmd=/mycluster/update/app2_check.sh
If you set AppType
to DualMaster
, the application starts on both the active and the standby hosts. The failure of the application on the active host causes the active database and all other applications on the host to fail over to the standby host. You can configure the failure interval, the number of restart attempts, and the uptime threshold by setting the AppFailureInterval
, AppRestartAttempts
and AppUptimeThreshold
attributes. These attributes have default values. For example:
[appDualDSN] MasterHosts=host1,host2,host3,host4 MasterVIP=192.168.1.1, 192.168.1.2 VIPInterface=eth0 VIPNetMask=255.255.255.0 AppName=update AppType=DualMaster AppStartCmd=/mycluster/update/app2_start.sh AppStopCmd=/mycluster/update/app2_stop.sh AppCheckCmd=/mycluster/update/app2_check.sh AppRestartAttempts=5 AppUptimeThreshold=300 AppFailureInterval=30
Note:
For a full description of all configuration attributes, see Appendix A, "TimesTen Configuration Attributes for Oracle Clusterware".If both master nodes fail and then come back up, Oracle Clusterware can automatically recover the master databases. Automatic recovery of temporary dual failure requires the following:
RETURN TWOSAFE
is not specified for the active standby pair.
AutoRecover
is set to y
.
RepBackupDir
specifies a directory on shared storage.
RepBackupPeriod
is set to a value greater than 0
.
If both master nodes fail permanently, Oracle Clusterware can automatically recover the master databases to two new nodes if the following is true:
Advanced availability is configured (virtual IP addresses and at least four hosts).
The active standby pair does not replicate cache groups.
A cache grid is not configured.
RETURN TWOSAFE
is not specified.
AutoRecover
is set to y
.
RepBackupDir
specifies a directory on shared storage.
RepBackupPeriod
must be set to a value greater than 0
.
TimesTen first performs a full backup of the active database and then performs incremental backups. You can specify the optional attribute RepFullBackupCycle
to manage when TimesTen performs subsequent full backup. By default, TimesTen performs a full backup after every five incremental backups.
If RepBackupDir
and RepBackupPeriod
are configured for backups, TimesTen performs backups for any master database that becomes active. It does not delete backups that were performed for a database that used to be active and has become the standby unless the database becomes active again. Ensure that the shared storage has enough space for two complete database backups. The ttCWAdmin -restore
command automatically chooses the correct backup files.
Incremental backups increase the amount of log records in the transaction log files. Ensure that the values of RepBackupPeriod
and RepFullBackupCycle
are small enough to prevent a large amount of log records in the transaction log file.
This example shows attribute settings for automatic recovery.
[autorecoveryDSN]
MasterHosts=host1,host2,host3,host4
MasterVIP=192.168.1.1, 192.168.1.2
VIPInterface=eth0
VIPNetMask=255.255.255.0
AutoRecover=y
RepBackupDir=/shared_drive/dsbackup
RepBackupPeriod=3600
If you have cache groups in the active standby pair or prefer to recover manually from failure of both master hosts, ensure that AutoRecover
is set to n
(the default). Manual recovery requires the following:
RepBackupDir
specifies a directory on shared storage
RepBackupPeriod
must be set to a value greater than 0
This example shows attribute settings for manual recovery. The default value for AutoRecover
is n
, so it is not included in the file.
[manrecoveryDSN]
MasterHosts=host1,host2,host3
MasterVIP=192.168.1.1, 192.168.1.2
VIPInterface=eth0
VIPNetMask=255.255.255.0
RepBackupDir=/shared_drive/dsbackup
RepBackupPeriod=3600
The RepDDL
attribute represents the SQL statement that creates the active standby pair. The RepDDL
attribute is optional. You can use it to exclude tables, cache groups and sequences from the active standby pair.
If you include RepDDL
in the cluster.oracle.ini
file, do not specify ReturnServiceAttribute
, MasterStoreAttribute
or SubscriberStoreAttribute
in the cluster.oracle.ini
file. Include those replication settings in the RepDDL
attribute.
When you specify a value for RepDDL
, use the <DSN>
macro for the database file name prefix. Use the <MASTERHOST[1]>
and <MASTERHOST[2]>
macros to specify the master host names. TimesTen substitutes the correct values from the MasterHosts
or MasterVIP
attributes, depending on whether your configuration uses virtual IP addresses. Similarly, use the <SUBSCRIBERHOST[
n
]>
macro to specify subscriber host names, where n
is a number from 1 to the total number of SubscriberHosts
attribute values or 1 to the total number of SubscriberVIP
attribute values if virtual IP addresses are used.
Use the RepDDL
attribute to exclude tables, cache groups, and sequences from the active standby pair:
[excludeDSN] MasterHosts=host1,host2,host3,host4 SubscriberHosts=host5,host6 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0 RepDDL=CREATE ACTIVE STANDBY PAIR \ <DSN> ON <MASTERHOST[1]>, <DSN> ON <MASTERHOST[2]> SUBSCRIBER <DSN> ON <SUBSCRIBERHOST[1]>\ EXCLUDE TABLE pat.salaries, \ EXCLUDE CACHE GROUP terry.salupdate, \ EXCLUDE SEQUENCE ttuser.empcount
The replication agent transmitter obtains route information as follows, in order of priority:
From the ROUTE
clause in the RepDDL
setting, if a ROUTE
clause is specified. Do not specify a ROUTE
clause if you are configuring advanced availability.
From Oracle Clusterware, which provides the private host names and public host names of the local and remote hosts as well as the remote daemon port number. The private host name is preferred over the public host name. If the replication agent transmitter cannot connect to the IPC socket, it attempts to connect to the remote daemon using information that Oracle Clusterware maintains about the replication scheme.
From the active and standby hosts. If they fail, then the replication agent chooses the connection method based on host name.
This is an example of specifying the ROUTE
clause in RepDDL
:
[routeDSN] MasterHosts=host1,host2,host3,host4 RepDDL=CREATE ACTIVE STANDBY PAIR \ <DSN> ON <MASTERHOST[1]>, <DSN> ON <MASTERHOST[2]>\ ROUTE MASTER <DSN> ON <MASTERHOST[1]> SUBSCRIBER <DSN> ON <MASTERHOST[2]>\ MASTERIP "192.168.1.2" PRIORITY 1\ SUBSCRIBERIP "192.168.1.3" PRIORITY 1\ MASTERIP "10.0.0.1" PRIORITY 2\ SUBSCRIBERIP "10.0.0.2" PRIORITY 2\ MASTERIP "140.87.11.203" PRIORITY 3\ SUBSCRIBERIP "140.87.11.204" PRIORITY 3\ ROUTE MASTER <DSN> ON <MASTERHOST[2]> SUBSCRIBER <DSN> ON <MASTERHOST[1]>\ MASTERIP "192.168.1.3" PRIORITY 1\ SUBSCRIBERIP "192.168.1.2" PRIORITY 1\ MASTERIP "10.0.0.2" PRIORITY 2\ SUBSCRIBERIP "10.0.0.1" PRIORITY 2\ MASTERIP "140.87.11.204" PRIORITY 3\ SUBSCRIBERIP "140.87.11.203" PRIORITY 3\
To create and initialize a cluster, perform these tasks:
Create the Oracle Clusterware resources to manage virtual IP addresses
Configure an Oracle database as a disaster recovery subscriber
Configure a read-only subscriber that is not managed by Oracle Clusterware
If you plan to have more than one active standby pair in the cluster, see "Include more than one active standby pair in a cluster".
If you want to configure an Oracle database as a remote disaster recovery subscriber, see "Configure an Oracle database as a disaster recovery subscriber".
If you want to set up a read-only subscriber that is not managed by Oracle Clusterware, see "Configure a read-only subscriber that is not managed by Oracle Clusterware".
Install Oracle Clusterware. By default, the installation occurs on all hosts concurrently. See Oracle Clusterware installation documentation for your platform.
Oracle Clusterware starts automatically after successful installation.
Note:
You can verify whether Oracle Clusterware is running on all hosts in the cluster by executing the following:crsctl check crs -all
Install TimesTen in the same location on each host in the cluster, including extra hosts. The instance name must be the same on each host. The user name of the instance administrator must be the same on all hosts. The TimesTen instance administrator must belong to the same UNIX primary group as the Oracle Clusterware installation owner.
The installer prompts you for values for the following, each of which are stored in the ttcrsagent.options
file:
The TCP/IP port number associated with the TimesTen cluster agent. The port number must be the same on all nodes of the cluster. If you do not provide a port number, then TimesTen adds six to the default TimesTen daemon port number to be the TCP/IP port number associated with the TimesTen cluster agent. Thus, the default daemon port number associated with the TimesTen cluster agent is 53398 for 32-bit systems and 53402 for 64-bit systems.
The Oracle Clusterware location. The location must be the same on each host.
The hosts included in the cluster, including spare hosts, with host names separated by commas. This list must be the same on each host.
The ttCWAdmin –init
and ttCWAdmin –shutdown
commands use the ttcrsagent.options
file to initiate and shut down the TimesTen cluster. The ttcrsagent.options
file is located in the TimesTen daemon home directory.
You should not manually alter the ttcrsagent.options
file. Instead, use the ttmodinstall -crs
command to create or modify the information in this file after the TimesTen cluster has been initiated. You can also use the -record
and -batch
options for setup.sh
to perform identical installations on additional hosts.
The current home location of Oracle Clusterware is set in the CRS_HOME
environment variable. In addition, the ttmodinstall -crs
command shows the current location of the Oracle Clusterware home as part of the prompts.
Note:
For more information on thettcrsagent.options
file, see "Start the TimesTen cluster agent". For more information about ttmodinstall
, see "ttmodinstall" in Oracle TimesTen In-Memory Database Reference.The following example shows how the ttmodinstall -crs
prompts for you to modify each item in the ttcrsagent.options
file:
% ttmodinstall -crs Cannot find instance_info file : /etc/TimesTen/instance_info Would you like to modify the existing TimesTen Replication with Oracle Clusterware configuration? [ no ] yes This TimesTen instance is configured to use an Oracle Clusterware installation located in : /mydir/oracle/crs/app/11.2.0/grid Would you like to change this value? [ no ] no The TimesTen Clusterware agent is configured to use port 54504 Would you like to change this value? [ no ] no The TimesTen Clusterware agent is currently configured with these nodes : node1 node2 node3 node4 Would you like to change these values? [ no ] Overwrite the existing TimesTen Clusterware options file? [ no ] no
TimesTen cluster information is stored in the Oracle Cluster Registry (OCR). As the root user, enter this command:
ttCWAdmin -ocrConfig
As long as Oracle Clusterware and TimesTen are installed on the hosts, this step never needs to be repeated.
Start a TimesTen cluster agent and TimesTen cluster daemon monitor on all hosts in the cluster by executing the ttCWAdmin -init
command. You can execute this command on any host in the cluster that is defined in the ttcrsagent.options
file.
For example:
ttCWAdmin -init
The ttCWAdmin -init
command performs the following:
Reads the ttcrsagent.options
file and launches the TimesTen main daemon on each of the hosts defined in this file.
Starts and registers the TimesTen cluster agent (ttCRSAgent
) and the TimesTen cluster daemon monitor (ttCRSDaemon
) on the all hosts in the cluster. There is one TimesTen cluster agent and one TimesTen cluster daemon monitor for the TimesTen installation on each host. When the TimesTen cluster agent has started, Oracle Clusterware begins monitoring the TimesTen daemon on each host and restarts a TimesTen daemon if it fails.
To start and register the TimesTen cluster agent (ttCRSAgent
) and the TimesTen cluster daemon monitor (ttCRSDaemon
) on specific hosts in the cluster, use the -hosts
command to specify the desired hosts in the cluster to start.
ttCWAdmin -init -hosts "host1, host2"
Create a database on the host where you intend the active database to reside. The DSN must be the same as the database file name.
Create schema objects (such as tables, AWT cache groups, and read-only cache groups) and populate with data as appropriate. However, before you create cache groups, you must first decide when to load the cache groups.
For best performance, load the cache group tables from the Oracle database tables before the ttCWAdmin -create
command. There is less performance overhead when cache groups are loaded with initial data before the duplicate is performed on the active master to create the standby master (and any subscribers).
For this option, perform the following:
Start the cache agent as follows:
Command> call ttCacheStart;
Note:
Since this is before thettCWAdmin -start
command, you can start the cache agent at this time. The ttCWAdmin -start
command notes that the cache agent is already started and continues.Use the LOAD CACHE GROUP
statement to load the cache group tables from the Oracle database tables.
If using autorefresh cache groups, set the autorefresh state to pause with the ALTER CACHE GROUP SET AUTOREFRESH STATE PAUSED
statement. The autorefresh state will be set to ON
as part of the ttCWAdmin -start
command.
The following example demonstrates how to create a read-only autorefresh cache group, load the data, and then set the autorefresh state to pause:
Command> call ttCacheStart; Command> CREATE READONLY CACHE GROUP my_cg AUTOREFRESH MODE INCREMENTAL INTERVAL 60 SECONDS FROM t1 (c1 NUMBER(22) NOT NULL PRIMARY KEY, c2 DATE, c3 VARCHAR(30)); Command> LOAD CACHE GROUP my_cg COMMIT EVERY 100 ROWS PARALLEL 4; Command> ALTER CACHE GROUP my_cg SET AUTOREFRESH STATE PAUSED;
Alternatively, wait to load the cache group tables after the ttCWAdmin -start
as described in "Load cache groups". The data will be replicated to the standby master and any subscribers.
On all hosts that are to be included in the cluster, create the system DSN (sys.odbc.ini
) files. The DataStore
attribute and the Data Source Name
must be the same as the entry name for the cluster.oracle.ini
file. See "Configuring Oracle Clusterware management with the cluster.oracle.ini file" for information about the contents of the sys.odbc.ini
files.
Create a cluster.oracle.ini
file as a text file. See "Configuring Oracle Clusterware management with the cluster.oracle.ini file" for details about its contents and acceptable locations for the file.
Advanced availability involves configuring spare master or subscriber hosts that are idle until needed to replace master or subscriber hosts (used in the active standby pair replication scheme) that either shut down unexpectedly or experience an unrecoverable error. This is an optional step that is only necessary if you decide to configure advanced availability.
If you are planning on providing additional master or subscriber hosts for advanced availability, then you need to configure virtual IP addresses (one for each master host and subscriber actively used in the active standby pair). See "Configuring advanced availability" for more details on how many virtual IP addresses should be created.
In this case, perform the following:
Designate (or create) new virtual IP addresses on the network that are to be used solely for managing multiple hosts in a TimesTen replication environment managed by Oracle Clusterware.
Configure these VIP addresses for use to manage multiple hosts for advanced availability in the cluster.oracle.ini
file, as described in "Configuring advanced availability".
Create the Oracle Clusterware resources that manage these VIP addresses by executing the ttCWAdmin -createVIPs
command as the root
user on any host in the cluster.
For example:
ttCWAdmin -createVIPs -dsn myDSN
The VIP address names created by this command start with network_
followed by the TimesTen instance name, TimesTen instance administrator, and the DSN. Whereas, the VIP addresses created for use by Oracle Clusterware are prefixed with ora
.
Note:
ThettCWAdmin -createVIPs
command must be executed before the ttCWAdmin -create
command. If you decide that you want to use VIP addresses for advanced availability after you have executed the ttCWAdmin -create
command, you must perform the following:
Execute ttCWadmin -drop
to drop the active standby pair replication scheme.
Add VIP addresses into cluster.oracle.ini
file.
Execute ttCWadmin -createVIPs
to create the resources to manage the VIP addresses.
Execute ttCWAdmin -create
to create the active standby pair replication scheme managed by Oracle Clusterware.
Once created, the only way to drop the Oracle Clusterware resources that manage the VIP addresses is to execute the ttCWAdmin -dropVIPs
command. Before you can drop the virtual IP addresses, you must first execute the ttCWAdmin -drop
command.
The following is an example of how to drop the virtual IP addresses:
ttCWAdmin -dropVIPs -dsn myDSN
For an example of when to use the ttCWAdmin -dropVIPs
command, see "Removing an active standby pair from a cluster".
Create an active standby pair replication scheme by executing the ttCWAdmin -create
command on any host in the cluster.
Note:
Thecluster.oracle.ini
file contains the configuration needed to perform the ttCWAdmin -create
command and so must reachable by the ttCWAdmin
executable. See "Configuring Oracle Clusterware management with the cluster.oracle.ini file" for more details.For example:
ttCWAdmin -create -dsn myDSN
The ttCWAdmin -create
command prompts for the following:
Prompts for the name of a TimesTen user with ADMIN
privileges. If cache groups are being managed by Oracle Clusterware, enter the TimesTen cache manager user name.
Prompts for the TimesTen password for the previously entered user name.
If cache groups are being used, prompts for the password for the Oracle user that has the same name as the cache manager user. This password is provided in the OraclePWD
connection attribute when the cache manager user connects.
Prompts for a random string used to encrypt the above information.
If you want to specify the path and name of a file to be used as the cluster.oracle.ini
file, use the -ttclusterini
command.
ttCWAdmin -create -dsn myDSN -ttclusterini path/to/cluster/mycluster.ini
To drop the active standby pair, use the ttCWAdmin -drop
command, as follows:
ttCWAdmin -drop -dsn myDSN
Note:
If your application connects to the TimesTen database using the virtual IP address, then this connection drops with thettCWAdmin -drop
command, since the virtual IP address is managed by Oracle Clusterware. However, if your application connects to the TimesTen database using the host name, the connection is not dropped.For examples showing the sequence in which to use the ttCWAdmin -create
and ttCWAdmin -drop
commands, see "Managing active standby pairs in a cluster" and "Managing read-only subscribers in the active standby pair".
Start the cluster with the active standby pair replication scheme by executing the ttCWAdmin -start
command on any host. This starts the cache agent (if not already started) and replication agent on the active database, performs the duplicate to create the standby master (and any subscribers), and starts the cache agent and replication agent on the standby master (and any subscribers).
If you do not specify -noApp
, the applications are also started. If you do specify -noApp
, then you can start and stop the applications with the -startApps
and -stopApps
commands respectively.
For example:
ttCWAdmin -start -dsn myDSN
This command starts the following processes for the active standby pair:
Monitor for application AppName
The following example starts the cache and replication agents, but does not start the applications because of the inclusion of the -noapp
command:
ttCWAdmin -start -noapp -dsn myDSN
To start and stop applications, use the -startApps
and -stopApps
commands as shown below:
ttCWAdmin -startapps -dsn myDSN ... ttCWAdmin -stopapps -dsn myDSN
To stop the cache agent and replication agent and disconnect the application from both databases, execute the ttCWAdmin -stop
command.
ttCWAdmin -stop -dsn myDSN
Note:
If your application connects to the TimesTen database using a virtual IP address, then this connection drops with thettCWAdmin -stop
command, since the virtual IP address is managed by Oracle Clusterware. However, if your application connects to the TimesTen database using the host name, the connection is not dropped; however, replication to the standby master does not occur.For examples showing the sequence in which to use the ttCWAdmin -start
and ttCWAdmin -stop
commands, see "Managing active standby pairs in a cluster" and "Managing read-only subscribers in the active standby pair".
If the active standby pair includes cache groups and you have not already loaded the cache group (as described in "Create and populate a TimesTen database on one host"), use the LOAD CACHE GROUP
statement to load the cache group tables from the Oracle database tables.
For more information on when to load cache groups, see "Create and populate a TimesTen database on one host".
If you want to use Oracle Clusterware to manage more than one active standby pair in a cluster, include additional configuration in the cluster.oracle.ini
file. Oracle Clusterware can only manage more than one active standby pair in a cluster if all TimesTen databases are a part of the same TimesTen instance on a single host.
For example, the following cluster.oracle.ini
file contains configuration information for two active standby pair replication schemes on the same host:
Note:
For details on configuration attributes in thecluster.oracle.ini
file, see Appendix A, "TimesTen Configuration Attributes for Oracle Clusterware".[advancedSubscriberDSN] MasterHosts=host1,host2,host3 SubscriberHosts=host4, host5 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0 [advSub2DSN] MasterHosts=host1,host2,host3 SubscriberHosts=host4, host5 MasterVIP=192.168.1.4, 192.168.1.5 SubscriberVIP=192.168.1.6 VIPInterface=eth0 VIPNetMask=255.255.255.0
Perform these tasks for additional replication schemes:
Create and populate the databases.
Create the virtual IP addresses. Use the ttCWAdmin -createVIPs
command.
Create the active standby pair replication scheme. Use the ttCWAdmin -create
command.
Start the active standby pair. Use the ttCWAdmin -start
command.
You can create an active standby pair on the primary site with an Oracle database as a remote disaster recovery subscriber. See "Using a disaster recovery subscriber in an active standby pair". Oracle Clusterware manages the active standby pair, but does not manage the disaster recovery subscriber. The user must perform a switchover if the primary site fails.
To use Oracle Clusterware to manage an active standby pair that has a remote disaster recovery subscriber, perform these tasks:
Use the RepDDL
or RemoteSubscriberHosts
Clusterware attribute to provide information about the remote disaster recovery subscriber. For example:
[advancedDRsubDSN] MasterHosts=host1,host2,host3 SubscriberHosts=host4, host5 RemoteSubscriberHosts=host6 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0 CacheConnect=y
Use ttCWAdmin -create
to create the active standby pair replication scheme on the primary site. This does not create the disaster recovery subscriber.
Use ttCWAdmin -start
to start the active standby pair replication scheme.
Load the cache groups that are replicated by the active standby pair.
Set up the disaster recovery subscriber using the procedure in "Rolling out a disaster recovery subscriber".
You can include a read-only TimesTen subscriber database that is not managed by Oracle Clusterware. Perform these tasks:
Include the RemoteSubscriberHosts
Clusterware attribute in the cluster.oracle.ini
file. For example:
[advancedROsubDSN] MasterHosts=host1,host2,host3 RemoteSubscriberHosts=host6 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0
Use ttCWAdmin -create
to create the active standby pair replication scheme on the primary site.
Use ttCWAdmin -start
to start the active standby pair replication scheme. This does not create the read-only subscriber.
Use the ttRepStateGet
built-in procedure to verify that the state of the standby database is STANDBY
.
On the subscriber host, use ttRepAdmin -duplicate
option to duplicate the standby database to the read-only subscriber. See "Duplicating a database".
Start the replication agent on the subscriber host.
To add or drop a read-only subscriber to or from an existing configuration, see "Adding or dropping a read-only subscriber not managed by Oracle Clusterware".
To rebuild a read-only subscriber, see "Rebuilding a read-only subscriber not managed by Oracle Clusterware".
You can use the TimesTen implementation of Oracle Clusterware to manage a cache grid when each grid member is an active standby pair. TimesTen does not support using Oracle Clusterware to manage standalone grid members.
This section includes:
See "Install TimesTen on each host" for installation requirements. In addition, each grid member must have a DSN that is unique within the cache grid.
Perform the tasks described in "Creating and initializing a cluster" for each grid member. Include the GridPort Clusterware attribute in the cluster.oracle.ini
file as described in "Including the active standby pair in a cache grid". Ensure that the specified port numbers are not in use.
The ttCWAdmin -start
command automatically attaches a grid member to the cache grid. The ttCWAdmin -stop
command automatically detaches a grid member from the cache grid.
If both nodes of an active standby pair grid member fail, then the grid member fails. Oracle Clusterware evicts the failed grid member from the grid automatically. However, when a cache grid is configured, any further automatic recovery after a dual failure, whether temporary or permanent, is not possible. In this case, you can only recover manually. For details, see "Manual recovery of both nodes of an active standby pair grid member".
You can add, drop, or change a cache group while the active master database is attached to the grid.
Use the ttCWAdmin -beginAlterSchema
command to make these schema changes. This command stops the replication agents on both the active and standby master nodes, but allows the active master database to remain attached to the grid. The ttCWAdmin -endAlterSchema
command initiates a duplicate to propagate certain changes to the standby master database (and any subscribers), registers the altered replication scheme, restarts both replication agents, and reinstates Oracle Clusteware control.
Note:
ThettCWadmin -endAlterSchema
command initiates a duplicate for this case since cache groups are included in the replication schema, but the DDL statements for cache groups are not replicated. For full details, see "Changing the schema".To add or drop a replicated table into the active standby pair, see "Making DDL changes in an active standby pair".
Perform these steps on the active database of each active standby pair grid member.
Note:
These steps are the same whether the active standby pair is or is not included in a cache grid.Enable the addition of the cache group to the active standby pair by temporarily suspending Oracle Clusterware management and stopping the replication agents with the ttCWAdmin -beginAlterSchema
command.
ttCWAdmin -beginAlterSchema -dsn advancedDSN
Create the cache group.
If the cache group is a read-only cache group, alter the active standby pair to include the cache group.
ALTER ACTIVE STANDBY PAIR INCLUDE CACHE GROUP samplecachegroup;
Complete your changes by executing the ttCWAdmin -endAlterSchema
command. Since you added a cache group object, a duplicate occurs to propagate these schema changes to the standby master database.
ttCWAdmin -endAlterSchema -dsn advancedDSN
You can load the cache group at any time after you create the cache group.
Perform these steps to drop a cache group.
Note:
These steps are the same whether the active standby pair is or is not included in a cache grid.Unload the cache group. When using a cache grid, you must unload the cache group in all members of the cache grid.
CALL ttOptSetFlag('GlobalProcessing', 1); UNLOAD CACHE GROUP samplecachegroup;
On the active database of an active standby pair, enable dropping the cache group.
ttCWAdmin -beginAlterSchema -dsn advancedDSN
If the cache group is a read-only cache group, alter the active standby pair to exclude the cache group.
ALTER ACTIVE STANDBY PAIR EXCLUDE CACHE GROUP samplecachegroup;
If the cache group is a read-only cache group, set the autorefresh state to PAUSED
.
ALTER CACHE GROUP samplecachegroup SET AUTOREFRESH STATE PAUSED;
Drop the cache group.
DROP CACHE GROUP samplecachegroup;
If the cache group was a read-only cache group, run the TimesTen_install_dir
/oraclescripts/cacheCleanUp.sql
SQL*Plus script as the cache administration user on the Oracle database to drop the Oracle database objects used to implement autorefresh operations.
Complete your changes by executing the ttCWAdmin -endAlterSchema
command. Since you dropped a cache group object, a duplicate occurs to propagate these schema changes to the standby master database.
ttCWAdmin -endAlterSchema -dsn advancedDSN
Repeat steps 2 through 7 on the active database of each active standby pair grid member.
To change an existing cache group, first drop the existing cache group as described in "Drop a cache group". Then add the cache group with the desired changes as described in "Add a cache group".
Oracle Clusterware can recover automatically from many kinds of failures. The following sections describe several failure scenarios and how Oracle Clusterware manages the failures.
How TimesTen performs recovery when Oracle Clusterware is configured
Perform a forced switchover after failure of the active database or host
The TimesTen database monitor (ttCRSmaster
process) performs recovery. It attempts to connect to the failed database without using the forceconnect
option. If the connection fails with error 994 (Data store connection terminated
), the database monitor tries to connect 10 times. If the connection fails with error 707 (Attempt to connect to a data store that has been manually unloaded from RAM
), the database monitor changes the RAM policy and tries to connect again. If the database monitor cannot connect, it returns connection failure.
If the database monitor can connect to the database, then it performs these tasks:
It queries the CHECKSUM
column in the TTREP.REPLICATIONS
replication table.
If the value in the CHECKSUM
column matches the checksum stored in the Oracle Cluster Registry, then the database monitor verifies the role of the database. If the role is 'ACTIVE
', then recovery is complete.
If the role is not 'ACTIVE'
, then the database monitor queries the replication Commit Ticket Number (CTN) in the local database and the CTN in the active database to find out whether there are transactions that have not been replicated. If all transactions have been replicated, then recovery is complete.
If the checksum does not match or if some transactions have not been replicated, then the database monitor performs a duplicate operation from the remote database to re-create the local database.
If the database monitor fails to connect with the database because of error 8110 or 8111 (master catchup required or in progress), then it uses the forceconnect=1
option to connect and starts master catchup. Recovery is complete when master catchup has been completed. If master catchup fails with error 8112 (Operation not permitted
), then the database monitor performs a duplicate operation from the remote database. For more information about master catchup, see "Automatic catch-up of a failed master database".
If the connection fails because of other errors, then the database monitor tries to perform a duplicate operation from the remote database.
The duplicate operation verifies that:
The remote database is available.
The replication agent is running.
The remote database has the correct role. The role must be 'ACTIVE'
when the duplicate operation is attempted for creation of a standby database. The role must be 'STANDBY'
or 'ACTIVE'
when the duplicate operation is attempted for creation of a read-only subscriber.
When the conditions for the duplicate operation are satisfied, the existing failed database is destroyed and the duplicate operation starts.
If there is a failure on the node where the active database resides, Oracle Clusterware automatically changes the state of the standby database to 'ACTIVE'
. If application failover is configured, then the application begins updating the new active database.
Figure 8-2 shows that the state of the standby database has changed to 'ACTIVE'
and that the application is updating the new active database.
Figure 8-2 Standby database becomes active
Oracle Clusterware tries to restart the database or host where the failure occurred. If it is successful, then that database becomes the standby database.
Figure 8-3 shows a cluster where the former active node becomes the standby node.
Figure 8-3 Standby database starts on former active host
If the failure of the former active node is permanent and advanced availability is configured, Oracle Clusterware starts a standby database on one of the extra nodes.
Figure 8-4 shows a cluster in which the standby database is started on one of the extra nodes.
Figure 8-4 Standby database starts on extra host
If you do not want to wait for these automatic actions to occur, see "Perform a forced switchover after failure of the active database or host".
If there is a failure on the standby node, Oracle Clusterware first tries to restart the database or host. If it cannot restart the standby database on the same host and advanced availability is configured, Oracle Clusterware starts the standby database on an extra node.
Figure 8-5 shows a cluster in which the standby database is started on one of the extra nodes.
If there is a failure on a subscriber node, Oracle Clusterware first tries to restart the database or host. If it cannot restart the database on the same host and advanced availability is configured, Oracle Clusterware starts the subscriber database on an extra node.
This section includes these topics:
Manual recovery of both nodes of an active standby pair grid member
Manual recovery to the same master nodes when databases are corrupt
Oracle Clusterware can achieve automatic recovery from temporary failure on both master nodes after the nodes come back up if:
RETURN TWOSAFE
is not specified for the active standby pair.
AutoRecover
is set to y
.
RepBackupDir
specifies a directory on shared storage.
RepBackupPeriod
is set to a value greater than 0
.
Oracle Clusterware can achieve automatic recovery from permanent failure on both master nodes if:
Advanced availability is configured (virtual IP addresses and at least four hosts).
The active standby pair does not replicate cache groups.
A cache grid is not configured.
RETURN TWOSAFE
is not specified for the active standby pair.
AutoRecover
is set to y
.
RepBackupDir
specifies a directory on shared storage.
RepBackupPeriod
is set to a value greater than 0
.
See "Recovering from permanent failure of both master nodes" for examples of cluster.oracle.ini
files.
If both nodes of an active standby pair grid member fail, then the grid member fails. Oracle Clusterware evicts the failed grid member from the grid automatically. After the failed grid member is removed from the grid, you can continue to recover manually. However, when a cache grid is configured, any further automatic recovery after a dual failure, whether temporary or permanent, is not possible.
If the active standby pair grid member is in an asynchronous replication scheme, the grid member is recovered automatically and reattached to the grid. If the active standby pair grid member is in a replication scheme with RETURN TWOSAFE
configured, perform these steps to recover the grid member and reattach it to the grid:
Stop the replication agent and the cache agent and disconnect the application from both databases. This step detaches the grid member from the grid.
ttCWAdmin -stop advancedGridDSN
Drop the active standby pair.
ttCWAdmin -drop advancedGridDSN
Create the active standby pair replication scheme.
ttCWAdmin -create advancedGridDSN
Start the active standby pair replication scheme. This step attaches the grid member to the grid.
ttCWAdmin -start advancedGridDSN
This section assumes that the failed master nodes are recovered to new hosts on which TimesTen and Oracle Clusterware are installed. These steps use the manrecoveryDSN
database and cluster.oracle.ini
file for examples.
To perform manual recovery in an advanced availability configuration, perform these tasks:
Ensure that the TimesTen cluster agent is running on the local host.
ttCWAdmin -init -hosts localhost
Restore the backup database. Ensure that there is not already a database on the host with the same DSN as the database you want to restore.
ttCWAdmin -restore -dsn manrecoveryDSN
If there are cache groups in the database, drop and re-create the cache groups.
If the new hosts are not already specified by MasterHosts
and SubscriberHosts
in the cluster.oracle.ini
file, then modify the file to include the new hosts.
These steps use manrecoveryDSN
. This step is not necessary for manrecoveryDSN
because extra hosts are already specified in the cluster.oracle.ini
file.
Re-create the active standby pair replication scheme.
ttCWAdmin -create -dsn manrecoveryDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn manrecoveryDSN
This section assumes that the failed master nodes are recovered to new hosts on which TimesTen and Oracle Clusterware are installed. These steps use the basicDSN
database and cluster.oracle.ini
file for examples.
To perform manual recovery in a basic availability configuration, perform these steps:
Acquire new hosts for the databases in the active standby pair.
Ensure that the TimesTen cluster agent is running on the local host.
ttCWAdmin -init -hosts localhost
Restore the backup database. Ensure that there is not already a database on the host with the same DSN as the database you want to restore.
ttCWAdmin -restore -dsn basicDSN
If there are cache groups in the database, drop and re-create the cache groups.
Update the MasterHosts
and SubscriberHosts
entries in the cluster.oracle.ini
file. This example uses the basicDSN
database. The MasterHosts
entry changes from host1
to host10
. The SubscriberHosts
entry changes from host2
to host20
.
[basicDSN] MasterHosts=host10,host20
Re-create the active standby pair replication scheme.
ttCWAdmin -create -dsn basicDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn basicDSN
Failures can occur on both master nodes so that the databases are corrupt. If you want to recover to the same master nodes, perform the following steps:
Ensure that the replication agent and the cache agent are stopped and that applications are disconnected from both databases. This example uses the basicDSN
database.
ttCWAdmin -stop -dsn basicDSN
On the node where you want the new active database to reside, destroy the databases by using the ttDestroy
utility.
ttDestroy basicDSN
Restore the backup database.
ttCWAdmin -restore -dsn basicDSN
If there are cache groups in the database, drop and re-create the cache groups.
Re-create the active standby pair replication scheme.
ttCWAdmin -create -dsn basicDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn basicDSN
You can configure an active standby pair to have a return service of RETURN TWOSAFE
by using the ReturnServiceAttribute
Clusterware attribute in the cluster.oracle.ini
file. When RETURN TWOSAFE
is configured, the database logs may be available on one or both nodes after both nodes fail.
This cluster.oracle.ini
example includes backup configuration in case the database logs are not available:
[basicTwosafeDSN]
MasterHosts=host1,host2
ReturnServiceAttribute=RETURN TWOSAFE
RepBackupDir=/shared_drive/dsbackup
RepBackupPeriod=3600
Perform these recovery tasks:
Ensure that the replication agent and the cache agent are stopped and that applications are disconnected from both databases.
ttCWAdmin -stop -dsn basicTwosafeDSN
Drop the active standby pair.
ttCWAdmin -drop -dsn basicTwosafeDSN
Decide whether the former active or standby database is more up to date and re-create the active standby pair using the chosen database. The command prompts you to choose the host on which the active database resides.
ttCWAdmin -create -dsn basicTwosafeDSN
If neither database is usable, restore the database from backups.
ttCWAdmin -restore -dsn basicTwosafeDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn basicTwosafeDSN
Approach a failure of more than two master hosts as a more extreme case of dual host failure. Use these guidelines:
Address the root cause of the failure if it is something like a power outage or network failure.
Identify or obtain at least two healthy hosts for the active and standby databases.
Update the MasterHosts
and SubscriberHosts
entries in the cluster.oracle.ini
file.
See "Manual recovery for advanced availability" and "Manual recovery for basic availability" for guidelines on subsequent actions to take.
If you want to force a switchover to the standby database without waiting for automatic recovery to be performed by TimesTen and Oracle Clusterware, you can write an application that uses Oracle Clusterware commands.
Perform the following:
Use the crsctl stop resource
command to stop the ttCRSmaster
resource on the active database. This causes the role of the standby database to change to active.
Use the crsctl start resource
command to restart the ttCRSmaster
resource on the former active database. This causes the database to recover and become the standby database.
The following example demonstrates a forced switchover from the active database on host1
to the standby database on host2
.
Find all TimesTen resources using the crsctl status resource
command.
% crsctl status resource | grep TT NAME=TT_Activeservice_tt1122_ttadmin_REP1 NAME=TT_Agent_tt1122_ttadmin_HOST1 NAME=TT_Agent_tt1122_ttadmin_HOST2 NAME=TT_App_tt1122_ttadmin_REP1_updateemp NAME=TT_Daemon_tt1122_ttadmin_HOST1 NAME=TT_Daemon_tt1122_ttadmin_HOST2 NAME=TT_Master_tt1122_ttadmin_REP1_0 NAME=TT_Master_tt1122_ttadmin_REP1_1 NAME=TT_Subservice_tt1122_ttadmin_REP1
Find the host where the active database resides by retrieving the status of the ttCRSActiveService
resource.
% crsctl status resource TT_Activeservice_tt1122_ttadmin_REP1 NAME=TT_Activeservice_tt1122_ttadmin_REP1 TYPE=application TARGET=ONLINE STATE=ONLINE on host1
There are two ttCRSmaster
resources listed in the initial status report. Discover which ttCRSmaster
resource is on the same host as the active database.
% crsctl status resource TT_Master_tt1122_ttadmin_REP1_0 NAME=TT_Master_tt1122_ttadmin_REP1_0 TYPE=application TARGET=ONLINE STATE=ONLINE on host1 % crsctl status resource TT_Master_tt1122_ttadmin_REP1_1 NAME=TT_Master_tt1122_ttadmin_REP1_1 TYPE=application TARGET=ONLINE STATE=ONLINE on host2
Stop the ttCRSmaster
resource on the host where the active database resides.
% crsctl stop resource TT_Master_tt1122_ttadmin_REP1_0 CRS-2673: Attempting to stop 'TT_Master_tt1122_ttadmin_REP1_0' on 'host1' CRS-2677: Stop of 'TT_Master_tt1122_ttadmin_REP1_0' on 'host1' succeeded
Restart the ttCRSmaster
resource on the former active database.
% crsctl start resource TT_Master_tt1122_ttadmin_REP1_0 CRS-2672: Attempting to start 'TT_Master_tt1122_ttadmin_REP1_0' on 'host1' CRS-2676: Start of 'TT_Master_tt1122_ttadmin_REP1_0' on 'host1' succeeded
Confirm that the forced switchover succeeds by checking where the ttCRSActiveService
and ttCRSsubservice
resources are located.
% crsctl status resource TT_Activeservice_tt1122_ttadmin_REP1 NAME=TT_Activeservice_tt1122_ttadmin_REP1 TYPE=application TARGET=ONLINE STATE=ONLINE on host2 % crsctl status resource TT_Subservice_tt1122_ttadmin_REP1 NAME=TT_Subservice_tt1122_ttadmin_REP1 TYPE=application TARGET=ONLINE STATE=ONLINE on host1
See Oracle Clusterware Administration and Deployment Guide for more information about the crsctl start resource
and crsctl stop resource
commands.
This section includes the following topics:
See "Performing an online TimesTen upgrade when using Oracle Clusterware" in Oracle TimesTen In-Memory Database Installation Guide.
The following sections describe how to add or remove hosts when using a cluster:
Adding a host requires that the cluster be configured for advanced availability. The examples in this section use the advancedSubscriberDSN
.
To add two spare master hosts to a cluster, enter a command similar to the following:
ttCWAdmin -addMasterHosts -hosts "host8,host9" -dsn advancedSubscriberDSN
To add a spare subscriber host to a cluster, enter a command similar to the following:
ttCWAdmin -addSubscriberHosts -hosts "subhost1" -dsn advancedSubscriberDSN
Removing a host from the cluster requires that the cluster be configured for advanced availability. MasterHosts
must list more than two hosts if one of the master hosts is to be removed. SubscriberHosts
must list at least one more host than the number of subscriber databases if one of the subscriber hosts is to be removed.
The examples in this section use the advancedSubscriberDSN
.
To remove two spare master host from the cluster, enter a command similar to the following:
ttCWAdmin -delMasterHosts "host8,host9" -dsn advancedSubscriberDSN
To remove a spare subscriber hosts from the cluster, enter a command similar to the following:
ttCWAdmin -delSubscriberHosts "subhost1" -dsn advancedSubscriberDSN
The following sections describe how to add or remove an active standby pair to a cluster:
To add an active standby pair (with or without subscribers) to a cluster that is already managing an active standby pair, perform these tasks:
Create and populate a database on the host where you intend the active database to reside initially. See "Create and populate a TimesTen database on one host".
Modify the cluster.oracle.ini
file. This example adds advSub2DSN
to the cluster.oracle.ini
file that already contains the configuration for advancedSubscriberDSN
. The new active standby pair is on different hosts from the original active standby pair.
[advancedSubscriberDSN] MasterHosts=host1,host2,host3 SubscriberHosts=host4, host5 MasterVIP=192.168.1.1, 192.168.1.2 SubscriberVIP=192.168.1.3 VIPInterface=eth0 VIPNetMask=255.255.255.0 [advSub2DSN] MasterHosts=host6,host7,host8 SubscriberHosts=host9, host10 MasterVIP=192.168.1.4, 192.168.1.5 SubscriberVIP=192.168.1.6 VIPInterface=eth0 VIPNetMask=255.255.255.0
Create new virtual IP addresses as the root
user.
ttCWAdmin -createVIPs -dsn advSub2DSN
Create the new active standby pair replication scheme.
ttCWAdmin -create -dsn advSub2DSN
Start the new active standby pair replication scheme.
ttCWAdmin -start -dsn advSub2DSN
To remove an active standby pair (with or without subscribers) from a cluster, perform these tasks:
Stop the replication agents on all databases in the active standby pair. This example uses advSub2DSN
, which was added in "Adding an active standby pair to a cluster".
ttCWAdmin -stop -dsn advSub2DSN
Drop the active standby replication scheme.
ttCWAdmin -drop -dsn advSub2DSN
Drop the virtual IP addresses for the active standby pair.
ttCWAdmin -dropVIPs -dsn advSub2DSN
Modify the cluster.oracle.ini
file (optional). Remove the entries for advSub2DSN
.
If you want to destroy the databases, log onto each host that was included in the configuration for this active standby pair and use the ttDestroy
utility.
ttDestroy advSub2DSN
For more information about ttDestroy
, see "ttDestroy" in Oracle TimesTen In-Memory Database Reference.
The following sections describe how to manage read-only subscribers in the active standby pair that is managed by Oracle Clusterware:
Removing a read-only subscriber managed by Oracle Clusterware
Adding or dropping a read-only subscriber not managed by Oracle Clusterware
Rebuilding a read-only subscriber not managed by Oracle Clusterware
To add a read-only subscriber that is to be managed by Oracle Clusterware to an active standby pair replication scheme, perform these steps:
Stop the replication agents on all databases. This example uses the advancedSubscriberDSN
, which already has a subscriber and is configured for advanced availability.
ttCWAdmin -stop -dsn advancedSubscriberDSN
Drop the active standby pair.
ttCWAdmin -drop -dsn advancedSubscriberDSN
Modify the cluster.oracle.ini
file.
Add the subscriber to the SubscriberHosts
attribute.
If the cluster is configured for advanced availability, add a virtual IP address to the SubscriberVIP
attribute.
See "Configuring advanced availability" for an example using these attributes.
Create the active standby pair replication scheme.
ttCWAdmin -create -dsn advancedSubscriberDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn advancedSubscriberDSN
To remove a read-only subscriber that is managed by Oracle Clusterware from an active standby pair, perform these steps:
Stop the replication agents on all databases. This example uses the advancedSubscriberDSN
, which has a subscriber and is configured for advanced availability.
ttCWAdmin -stop -dsn advancedSubscriberDSN
Drop the active standby pair.
ttCWAdmin -drop -dsn advancedSubscriberDSN
Modify the cluster.oracle.ini
file.
Remove the subscriber from the SubscriberHosts
attribute or remove the attribute altogether if there are no subscribers left in the active standby pair.
Remove a virtual IP from the SubscriberVIP
attribute or remove the attribute altogether if there are no subscribers left in the active standby pair.
Create the active standby pair replication scheme.
ttCWAdmin -create -dsn advancedSubscriberDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn advancedSubscriberDSN
You can add or drop a read-only subscriber that is not managed by Oracle Clusterware to or from an existing active standby pair replication scheme that is managed by Oracle Clusterware. Using the ttCWAdmin -beginAlterSchema
command enables you to add a subscriber without dropping and re-creating the replication scheme. Oracle Clusterware does not manage the subscriber, because it is not part of the configuration that was set up for Oracle Clusterware management.
Perform these steps:
Execute the ttCWAdmin -beginAlterSchema
command to stop the replication agent on the active and standby databases.
Using ttIsql
to connect to the active database, you can add or drop the subscriber to or from the replication scheme by using an ALTER ACTIVE STANDBY PAIR
statement. For example, to add a subscriber:
ALTER ACTIVE STANDBY PAIR ADD SUBSCRIBER ROsubDSN ON host6;
To drop a subscriber:
ALTER ACTIVE STANDBY PAIR DROP SUBSCRIBER ROsubDSN ON host6;
Execute the ttCWAdmin -endAlterSchema
command that registers the altered replication scheme and starts replication. If you are adding a subscriber, this also initiates a duplicate to the standby master database.
Execute the ttIsql repschemes
command to verify that the read-only subscriber has been added to or dropped from the replication scheme.
Use the ttRepStateGet
built-in procedure to verify that the state of the standby database is STANDBY
.
If you added a subscriber, then execute ttRepAdmin -duplicate
on the subscriber host to duplicate the standby database to the read-only subscriber. See "Duplicating a database".
If you added a subscriber, start the replication agent on the subscriber host.
If you added a subscriber, ensure that the read-only subscriber is included if the cluster is dropped and re-created by adding the RemoteSubscriberHosts Clusterware attribute for the read-only subscriber in the cluster.oracle.ini
file as described in Step 1 in "Configure a read-only subscriber that is not managed by Oracle Clusterware". Alternatively, if you dropped a subscriber, remove the RemoteSubscriberHosts
Clusterware attribute for the dropped subscriber in the cluster.oracle.ini
file (if it is configured).
Perform the following tasks to destroy and rebuild a read-only subscriber that is not managed by Oracle Clusterware:
Stop the replication agent on the subscriber host.
Use the ttDestroy
utility to destroy the subscriber database.
On the subscriber host, use ttRepAdmin -duplicate
to duplicate the standby database to the read-only subscriber. See "Duplicating a database".
When using Oracle Clusterware to manage an active standby pair, you can modify the schema by executing DDL statements as in a normal replication environment, except that Oracle Clusterware must start and stop all replication agents, when it is necessary to do so.
Thus, when you change the schema, note the following:
For those DDL statements on objects that are automatically replicated, you do not need to stop the replication agents. In this case, no further action is required, since these DDL statements are automatically propagated and applied to the standby master and any subscribers. The DDLReplicationLevel
connection attribute controls what DDL statements are replicated.
For those objects that are a part of the replication scheme, but any DDL statements executed on these objects are not replicated (these objects are listed in "Making other changes to an active standby pair"), run the Oracle Clusterware ttCWAdmin -beginAlterSchema
command on the active master, which stops the replication agents on each node in the replication scheme. Then, execute the DDL statement on the active master in the replication scheme. Finally, run the Oracle Clusterware ttCWAdmin -endAlterSchema
command on the active master to restart all replication agents.
Because these objects are a part of the replication scheme, but the DDL statements are not replicated, a duplicate occurs after the ttCWAdmin -endAlterSchema
command to propagate these schema changes to the standby master and any subscribers. This is the only scenario when a duplicate is used to propagate the schema changes.
Follow the instructions described in "Facilitating schema change for Oracle Clusterware".
For those DDL statements on objects that are not automatically replicated and are not part of the replication scheme, run the Oracle Clusterware ttCWAdmin -beginAlterSchema
command on the active master, which stops the replication agents on all nodes. Then, you can synchronize all nodes by manually executing these DDL statements as indicated in "Making DDL changes in an active standby pair." Finally, run the Oracle Clusterware ttCWAdmin -endAlterSchema
command on the active master to restart all replication agents.
Follow the instructions described in "Facilitating schema change for Oracle Clusterware".
Note:
The "Making DDL changes in an active standby pair" and "Making other changes to an active standby pair" sections describe which DDL statements are and are not automatically replicated for an active standby pair. These sections also describe what objects are a part of the replication scheme.Use the ttCWAdmin -beginAlterSchema
and -endAlterSchema
commands to facilitate the schema changes on the active and standby master databases that requires the replication agents are stopped.
The ttCWAdmin -beginAlterSchema
command prepares for schema changes by stopping replication agents on both the active and standby master nodes in preparation for any schema changes.
After you complete all schema changes, run the ttCWAdmin -endAlterSchema
command. For those objects that are a part of the replication scheme, but any DDL statements executed on these objects are not automatically replicated, a duplicate occurs after the ttCWAdmin -endAlterSchema
command to propagate only these schema changes to the standby and any subscribers. This command registers the altered replication scheme, restarts the replication agents on the active and standby master nodes, and reinstates Oracle Clusteware control.
Perform the following tasks when altering the schema of the active standby pair when using Oracle Clusterware:
Enable the changes to the schema of the active standby pair by stopping the replication agents on both the active and standby masters.
ttCWAdmin -beginAlterSchema -dsn advancedDSN
Make any desired schema changes.
If you create, alter, or drop any objects where the DDL for these objects are not replicated, you should also manually create, alter, or drop the same objects on the standby master and subscribers while the replication agents are inactive to ensure that the same objects exist on all databases in the replication scheme. For example, if you create a materialized view on the active database, create the materialized view on the databases on the standby master and subscriber nodes at this time.
If the object is not automatically replicated but is a part of the replication scheme, (such as a sequence) and you want to include it in the active standby pair replication scheme, alter the active standby pair.
ALTER ACTIVE STANDBY PAIR INCLUDE samplesequence;
If the object is a cache group, see the instructions for creating, altering, or dropping a cache group in "Making schema changes to active standby pairs in a grid".
Run the ttCWAdmin -endAlterSchema
command to restart the replication agents on the active and standby master nodes. If you modified objects that are a part of the replication scheme, but any DDL statements executed on these objects are not automatically replicated, a duplicate occurs after the ttCWAdmin -endAlterSchema
command to propagate only these schema changes to the standby and any subscribers.
ttCWAdmin -endAlterSchema -dsn advancedDSN
To add or drop a subscriber database or alter database attributes, perform the following tasks:
Stop the replication agents on the databases in the active standby pair. These commands use the advancedCacheDSN
as an example.
ttCWAdmin -stop -dsn advancedCacheDSN
Drop the active standby pair.
ttCWAdmin -drop -dsn advancedCacheDSN
Modify the schema as desired.
Re-create the active standby pair replication scheme.
ttCWAdmin -create -dsn advancedCacheDSN
Start the active standby pair replication scheme.
ttCWAdmin -start -dsn advancedCacheDSN
After a failover, the active and standby databases are on different hosts than they were before the failover. You can use the -switch
option of the ttCWAdmin
utility to restore the original configuration. Optionally, you can also use the -timeout
option with the -switch
option to set a timeout for the number of seconds to wait for the active and standby database switch to complete.
For example:
ttCWAdmin -switch -dsn basicDSN
Ensure that there are no open transactions before using the -switch
option. If there are open transactions, the command fails.
Note:
For more details on the-switch
and -timeout
options, see "ttCWAdmin" in the Oracle TimesTen In-Memory Database Reference.Figure 8-6 shows the hosts for an active standby pair. The active database resides on host A, and the standby database resides on host B.
Figure 8-6 Hosts for an active standby pair
The ttCWAdmin -switch
command performs these tasks:
Deactivates the TimesTen cluster agent (ttCRSAgent
) on host A (the active node).
Disables the database monitor (ttCRSmaster
) on host A.
Calls the ttRepSubscriberWait
, ttRepStop
and ttRepDeactivate
built-in procedures on host A.
Stops the active service (ttCRSActiveService
) on host A and reports a failure event to the Oracle Clusterware CRSD
process.
Enables monitoring on host A and moves the active service to host B.
Starts the replication agent on host A, stops the standby service (ttCRSsubservice
) on host B and reports a failure event to the Oracle Clusterware CRSD
process on host B.
Starts the standby service (ttCRSsubservice
) on host A.
When a cluster is configured for advanced availability, you can use the -relocate
option of the ttCWAdmin
utility to move a database from the local host to the next available spare host specified in the MasterHosts
attribute in the cluster.oracle.ini
file. If the database on the local host has the active role, the -relocate
option first reverses the roles. Thus, the newly migrated active database becomes the standby and the standby becomes the active.
The -relocate
option is useful for relocating a database if you decide to take the host offline. Ensure that there are no open transactions before you use the command.
If the -relocate
option requires a role switch, then you can optionally use the -timeout
option with the -relocate
option to set a timeout for the number of seconds to wait for the role switch.
For example:
ttCWAdmin -relocate -dsn advancedDSN
Note:
For more details on the-relocate
and -timeout
options, see "ttCWAdmin" in the Oracle TimesTen In-Memory Database Reference.If you decide to upgrade the operating system or hardware for a host or perform network maintenance, shut down Oracle Clusterware and disable automatic startup. Execute these Oracle Clusterware commands as root
or OS administrator:
# crsctl stop crs # crsctl disable crs
Shut down TimesTen. See "Shutting down a TimesTen application" in Oracle TimesTen In-Memory Database Operations Guide.
Perform the host maintenance. Then enable automatic startup and start Oracle Clusterware:
# crsctl enable crs # crsctl start crs
See Oracle Clusterware Administration and Deployment Guide for more information about these commands.
When all of the hosts in the cluster need to be brought down, stop Oracle Clusterware on each host individually. Execute these Oracle Clusterware commands as root
or OS administrator:
# crsctl stop crs # crsctl disable crs
Shut down TimesTen. See "Shutting down a TimesTen application" in Oracle TimesTen In-Memory Database Operations Guide.
Perform the maintenance. Then enable automatic startup and start Oracle Clusterware:
# crsctl enable crs # crsctl start crs
See Oracle Clusterware Administration and Deployment Guide for more information about these commands.
When you create the active standby pair replication scheme with the ttCWAdmin -create
command, Oracle Clusterware prompts for the required user names and passwords in order to manage the TimesTen environment. Oracle Clusterware stores these user names and passwords. After modifying any user name or password, you must execute the ttCWAdmin -reauthenticate
command to enable Oracle Clusterware to store these new user names and passwords.
Ensure that the DDLReplicationLevel
connection attribute is set to 3. This value replicates changes to the user names or passwords on the active master to the standby master.
Modify any of the user names or passwords in the same manner (and with the same restrictions) as described in "Changing user names or passwords used by replication".
Ensure that all password changes are replicated to the standby master by calling the ttRepSubscriberWait
built-in procedure (or the ttRepAdmin -wait
command) on the active master database using the DSN and host of the standby master database. For example, to ensure that all transactions are replicated to the master2
standby master on the host2
host:
Command> CALL ttRepSubscriberWait(NULL, NULL, 'master2', 'host2', -1);
Store the new passwords in Oracle Clusterware by executing the ttCWAdmin -reauthenticate
command.
ttCWAdmin -reauthenticate -dsn myDSN
This command prompts for the same information as requested for the ttCWAdmin -create
command, which is discussed in "Create an active standby pair replication scheme".
By default, the TimesTen database RAM policy is set to Always
when Oracle Clusterware manages the TimesTen database. However, if you stop Oracle Clusterware management, the TimesTen database RAM policy is set to In Use
.
If you no longer use Oracle Clusterware to manage TimesTen, you should set the TimesTen RAM policy to what is appropriate for your envioronment. Typically, the recommended setting is Manual
.
For more information on the TimesTen database RAM policy, see "Specifying a RAM policy" in the Oracle TimesTen In-Memory Database Operations Guide.
The following sections describe how to retrieve the status of the cluster:
The -status
option of the ttCWAdmin
utility reports information about all of the active standby pairs in an instance that are managed by the same instance administrator. If you specify the DSN, the utility reports information for the active standby pair with that DSN.
Example 8-1 Status after creating an active standby pair
After you have created an active standby pair replication scheme but have not yet started replication, ttCWAdmin -status
returns information such as this. Note that the grid states are displayed before replication is started, regardless of whether there is a cache grid.
$ ttCWAdmin -status TimesTen Cluster status report as of Thu Nov 11 13:54:35 2010 ==================================================================== TimesTen daemon monitors: Host:HOST1 Status: online Host:HOST2 Status: online ==================================================================== ==================================================================== TimesTen Cluster agents Host:HOST1 Status: online Host:HOST2 Status: online ==================================================================== Status of Cluster related to DSN MYDSN: ==================================================================== 1. Status of Cluster monitoring components: Monitor Process for Active datastore:NOT RUNNING Monitor Process for Standby datastore:NOT RUNNING Monitor Process for Master Datastore 1 on Host host1: NOT RUNNING Monitor Process for Master Datastore 2 on Host host2: NOT RUNNING 2.Status of Datastores comprising the cluster Master Datastore 1: Host:host1 Status:AVAILABLE State:ACTIVE Grid:NO GRID Master Datastore 2: Host:host2 Status:UNAVAILABLE State:UNKNOWN Grid:UNKNOWN ==================================================================== The cluster containing the replicated DSN is offline
Example 8-2 Status when the active database is running
After you have started the replication scheme and the active database is running but the standby database is not yet running, ttCWAdmin -status
returns information like this when a cache grid is not configured.
$ ttcwadmin -status TimesTen Cluster status report as of Thu Nov 11 13:58:25 2010 ==================================================================== TimesTen daemon monitors: Host:HOST1 Status: online Host:HOST2 Status: online ==================================================================== ==================================================================== TimesTen Cluster agents Host:HOST1 Status: online Host:HOST2 Status: online ==================================================================== Status of Cluster related to DSN MYDSN: ==================================================================== 1. Status of Cluster monitoring components: Monitor Process for Active datastore:RUNNING on Host host1 Monitor Process for Standby datastore:RUNNING on Host host1 Monitor Process for Master Datastore 1 on Host host1: RUNNING Monitor Process for Master Datastore 2 on Host host2: RUNNING 2.Status of Datastores comprising the cluster Master Datastore 1: Host:host1 Status:AVAILABLE State:ACTIVE Grid:NO GRID Master Datastore 2: Host:host2 Status:AVAILABLE State:IDLE Grid:NO GRID ==================================================================== The cluster containing the replicated DSN is online
If a cache grid is configured, then the last section appears as follows:
2.Status of Datastores comprising the cluster Master Datastore 1: Host:host1 Status:AVAILABLE State:ACTIVE Grid:AVAILABLE Master Datastore 2: Host:host2 Status:AVAILABLE State:IDLE Grid:NO GRID
Example 8-3 Status when the active and the standby databases are running
After you have started the replication scheme and the active database and the standby database are both running, ttCWAdmin -status
returns information like this when a cache grid is not configured.
$ ttcwadmin -status TimesTen Cluster status report as of Thu Nov 11 13:59:20 2010 ==================================================================== TimesTen daemon monitors: Host:HOST1 Status: online Host:HOST2 Status: online ==================================================================== ==================================================================== TimesTen Cluster agents Host:HOST1 Status: online Host:HOST2 Status: online ==================================================================== Status of Cluster related to DSN MYDSN: ==================================================================== 1. Status of Cluster monitoring components: Monitor Process for Active datastore:RUNNING on Host host1 Monitor Process for Standby datastore:RUNNING on Host host2 Monitor Process for Master Datastore 1 on Host host1: RUNNING Monitor Process for Master Datastore 2 on Host host2: RUNNING 2.Status of Datastores comprising the cluster Master Datastore 1: Host:host1 Status:AVAILABLE State:ACTIVE Grid:NO GRID Master Datastore 2: Host:host2 Status:AVAILABLE State:STANDBY Grid:NO GRID ==================================================================== The cluster containing the replicated DSN is online
If a cache grid is configured, then the last section appears as follows:
2.Status of Datastores comprising the cluster Master Datastore 1: Host:host1 Status:AVAILABLE State:ACTIVE Grid:AVAILABLE Master Datastore 2: Host:host2 Status:AVAILABLE State:STANDBY Grid:AVAILABLE
The monitor processes report events and errors to the ttcwerrors.log
and ttcwmsg.log
files. The files are located in the daemon_home
/info
directory. The default size of these files is the same as the default maximum size of the user log. The maximum number of log files is the same as the default number of files for the user log. When the maximum number of files has been written, additional errors and messages overwrite the files, beginning with the oldest file.
For the default values for number of log files and log file size, see "Modifying informational messages" in Oracle TimesTen In-Memory Database Operations Guide.