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Release Notes

Release Notes

BEA Liquid Data for WebLogicTM Release: 1.0
Date: October 2002
Revised: December 2002 for Release 1.0.1

About This BEA Liquid Data for WebLogic Release

Welcome to BEA Liquid Data for WebLogic! We are pleased to have you as a customer.

Liquid Data is real-time data integration technology built on the BEA WebLogic Server. Liquid Data real-time access to information in relational databases, XML files, Web services, and packaged and custom applications with Application Views. Liquid Data features an easy-to-use Data View Builder for drag-and-drop design and testing of queries using XML schema representations of the data in various types data sources. The Data Views generated as query results can also be used as Liquid Data sources.

These release notes include the following topics:

- What's New in Release 1.0.1?

- General Notes

- Miscellaneous Issues

- Known Limitations

- Where to Get Liquid Data Product Documentation

What's New in Release 1.0.1?

Release 1.0.1 of Liquid Data features enhanced platform support. In support of this release, the following information has been added to the product documentation:

- Enhanced platform support for HP UX, IBM AIX, and SuSE Linux for IBM is described in Supported Platforms and Databases in Installing Liquid Data.

- The following change requests have been added to the 1.0.1 documentation in Known Limitations with temporary workarounds provided:

- CR078812

- CR090898

- CR091015

- Information about which versions of XML schema are supported is provided in Which Versions of XML Schema Does Liquid Data Support? in Building Queries and Data Views.

General Notes

If you do not have Java executable in your PATH, please add it before running the Liquid Data installer. You should find one from the WebLogic Platform 7.0 SP1 distribution at:

>     PATH=BEA_HOME/jdk131_03/bin:$PATH

Miscellaneous Issues

1. For more information on how to remove Liquid Data from a domain, see "Uninstalling Liquid Data" in Post-Installation Tasks in Installing Liquid Data.

2. If the PointBase server is already started when you start the Liquid Data Sample server, you may get the following error message:

   >     The process cannot access the file because it is already being used by another process

   You can disregard this message. The server will start and run normally, regardless.

3. Do not use Ctl-C command to shut down the Liquid Data server. Doing so could corrupt the Liquid Data configuration files in the server domains (config.xml).

   Instead, make sure that you always shut down the server through the WebLogic Server Administration Console. For example, the WLS Administration Console using the default port is at the following URL for a local server:

   >     http://localhost:7001/console

   Instructions on how to shut down the Liquid Data server from the Administration Console are provided in Starting and Stopping the Server in the Liquid Data Administration Guide.

   For complete information on how to recover a corrupted configuration file, see "Backing Up Configuration Data" in the topic Recovering Failed Servers in the WebLogic Server system administration documentation.

Known Limitations

This section describes limitations in the current BEA Liquid Data Technical Preview release and includes possible workarounds, where applicable.

The table below lists a CR (Change Request) number for each problem. Refer to this number to conveniently track the solution as the problems are resolved.

Please contact BEA customer support at http://support.bea.com for assistance in tracking any unresolved problems.

CR070574 | There are some limitations with integrating complex Web services as data sources in Liquid Data.
Problem | 1. For document style Web services that return a complex type, the Data View Builder shows all types of individual elements as string types. 2. Array type in schemas is not supported with RPC style Web services. 3. WSDL with multiple ports is not supported. 4. Current support is only for SOAP binding; not for HTTP-GET and HTTP-POST Binding. 5. Access to secure Web services is not supported.
Platforms | All
Workaround | 1. For problem #1: Use a target schema with correct data types and use Automatic Type Casting feature in the Data View Builder to convert from string to required type. 2. For problem #2: If you want to use an array type in WSDL, then use document style Web services instead of RPC style Web services.
CR074366 | Liquid Data server requires restart to recognize schema changes to Liquid Data relational database data sources.
Problem | Schema changes to a Liquid Data RDBMS Data Source do not get picked up by the Liquid Data server until after it the server is restarted. For example, if you add a new table to a relational database you must restart the server to see the new table show up.
Platform | All
Workaround | When you make changes to schemas for relational database data sources, restart the Liquid Data server to refresh the data source schema cache and see the changes reflected in Liquid Data.
CR075825 | Liquid Data does not currently support direct access to stored procedures in relational databases.
Problem | Liquid Data currently does not offer a built-in feature for direct access to stored procedures in relational databases.
Platform | All
Workaround | You can leverage existing relational database "stored procedures" in any of the following ways: You can write a custom adapter using the ADK framework provided by WebLogic Integration (WLI). Make sure you use this adpater only for accesing stored procedures and not for general RDBMS access. You can write a Web service interface to stored procedures, then register the WSDL file to Liquid Data data source to access stored procedures. If for some reason you cannot use the above two approaches, then you can use Custom Functions to access stored procedures.
CR078812 | XML data sources in Liquid Data are not type-aware. Data in XML files is processed as "string" type, regardless of the type information in the associated schema.
Problem | In current releases, an XML data source in Liquid Data is not type-aware. Liquid Data processes the data in XML files as "string" type, regardless of the data types defined for elements and attributes in the associated schema. The type information in the schema is ignored by the XML data source.
Platform | All
Workaround | You can use automatic type casting in the Data View Builder to ensure that the appropriate data type is used. With automatic type casting set to on, then—depending on the target schema—type casting is done to convert from string to the appropriate type in the target schema. (For more information,see Using Automatic Type Casting and Type Casting Reference in the Building Queries and Data Views.) For hand-coded queries, it is the responsiblity of the designer to do the appropriate type casting.
CR078921 | In Data View Builder, stopping a query with Stop Query Execution button may cause a query result to hang.
Problem | In rare cases, clicking the "Stop Query Execution" button while a query is running will cause the query result that would otherwise run successfully to hang. The result will not be returned and the Data View Builder will need to be restarted.
Platforms | All
Workaround | If you encounter this behavior, restart the Data View Builder, open the project and re-run the query. We suggest that you do not stop query execution on subsequent tries for the particular queries for which you encounter this problem.
CR088338 | InstallAnywhere fails with JDK 1.4 and above
Problem | The Liquid Data installer requires that JAVA_HOME/bin in the PATH in order to work properly. Unfortunately, JDK 1.4 versions and higher do not function properly with InstallAnywhere; these versions of Java cause the installer to crash.
Platform | All
Workaround | Use the JDK version (1.3.1) that ships with WebLogic Platform 7.0—make sure JDK 1.3.1 is in your PATH as described in the Installation Guide.
CR081983 | Use of xfext:time-from-dateTime function in a query result shows a time that is one hour behind the actual time.
Problem | When you use the xfext:time-from-dateTime function in XQuery for a query, the XML query result will show a time that is one hour behind the intended time.
Platform | All
Workaround | This is a known Java Virtual Machine (JVM) bug from Sun Microsystems, Inc. (logged as ID: 4414844). As a workaround, add one hour to the time of day value when you build the query.
CR085437 | Liquid Data requires Compatibility Security. Liquid Data may not work with WebLogic Server (WLS) 7.0 security.
Problem | Liquid Data requires Compatibility Security. Liquid Data may not work with WebLogic Server (WLS) 7.0 security.
Platform | All
Workaround | Use Compatibility Security as described in the documentation.
CR085797 | On the Administration Console, the Upload File option overwrites an existing file of the same name in the repository without giving a warning that it's about to do so.
Problem | When you upload a file into the Liquid Data server repository via the Administration Console, you do will not get a prompt asking you to confirm an overwrite if the file already exists in the respository.
Platform | All
Workaround | Before uploading a file into the Liquid Data server repository, be sure to check whether the file already exists in the repository and determine whether you want that file overwritten or not. (See the topic "Uploading Files to the Server Repository" in Managing the Liquid Data Server Repository.)
CR085942 | Problems with undeploying Liquid Data on a WebLogic Server (WLS) domain
> Problem | During undeployment of LDS.ear, the following cleanup error message is displayed:
>     weblogic.management.NoAccessRuntimeException: Access not allowed
>     for subject: principals=[], on ResourceType: LDI:name=monitoring
>     Action: unregister, Target: null
This does not affect Liquid Data or any other Weblogic components.
Platform | All
Workaround | Disregard the error message.
CR086713 | If the WebLogic Server (WLS) thread count is greater than Maximum Connections set for a Liquid Data relational database data source, the Liquid Data server will respond with "No Connection Available" message.
Problem | When you run a query, if the WLS thread count is greater than the maximum connections set for a Liquid Data relational database data source, the Liquid Data server will respond with a"No Connection Available" message.
Platform | All
Workaround | In the Administration Console on the Liquid Data relational database data source, set "Maximum Connections" to 0 ( unlimited), or to some number greater than or equal to the WLS thread count. (See Configuring Access to Relational Databases in the Liquid Data Administration Guide.)
CR086826 | Liquid Data JSP tag libraries cannot be used to run queries on a remote domain.
Problem | Liquid Data JSP tag libraries cannot be used to run queries on a remote domain because JSP tag library API does not allow the programmer to specify security credentials.
Platform | All
Workaround | We recommend deploying Liquid Data in the domain where the JSP presentation layer is deployed. For example, if the JSP presentation layer is WebLogic Portal domain then deploy Liquid Data with the Portal. If the JSP presentation layser is some other portal solution or simple JSP pages, deploy Liquid Data in that domain. If for some reason the above solution is not feasible, we recommend that you wrap the Liquid Data EJB APIs into a tag library that allows you to specify the security parameters.
CR087058 | The Liquid Data installer overrides the beahomelist file
Problem | If you are using a NIS/NFS based file system and have Liquid Data installed on multiple systems, each time you run the installer it will rewrite the beahomelist file. The existing BEA homes from the previous install will not be listed in the new beahomelist. (The most recent installation will have its bea home in the list and it will be the only one listed).
Platform | All when using NIS/NFS based file system with Liquid Data installed on multiple systems.
Workaround | Edit the beahomelist file to include the appropriate BEA homes.
CR087295 | jaxa.exe error can occur during the Liquid Data server startup due to low memory resources when using the - server JVM argument
Problem | In some cases, when you start the Liquid Data Samples server you may encounter an error similar to the following: java.exe has generated errors and will be closed by Windows This will generally occur when your system memory resources are running low.
Platform | Windows only
Workaround | Since this error occurs when system memory resources are low, one of the following workarounds should get you past the error: Close some of the applications running on your machine. Increase your system memory. Edit the startWebLogic.cmd script and comment out the java option -server to get past this error. With -server option removed, Liquid Data will use fewer system resources. However, you will not be able to execute large queries or run multiple queries simultaneously in this mode.
CR087410, CR087443 | Removing a generated Web service from the Liquid Data web_services_gen directory does not automatically remove it from the WebLogic Server (WLS) Web services table as expected.
Problem | When a generated Web service is removed from the Liquid Data repository web_services_gen directory, it is undeployed and removed from the directory. At this point, Liquid Data console management should also automatically remove the Web service from the Web services table in the WLS Administration Console. But the Web service is not automatically removed—it still shows up in the WLS Web services table even after removal from the web_services_gen directory.
Platform | All
Workaround | Follow these steps to remove a generated Web service for a stored query in Liquid Data: 1. Use Administration Console to browse the web_services_gen directory in the Liquid Data server repository. (Click the Liquid Data node in the Administration Console, then click the Repository tab.) 2. Click the trashcan icon (Delete) next to the EAR file for the generated Web service that you intend to remove and confirm. 3. On the left pane of the Administration Console, click the Web Service Components folder to display the table of WLS Web service components. 4. In the table, click the trashcan icon (Delete) next to the EAR file for the generated Web service that you removed earlier from Liquid Data and confirm.
CR087574 | If you want to deploy a Liquid Data generated Web service, you must add CR084935_70sp1_3.jar to your CLASSPATH.
Problem | CR084935_70sp1_3.jar is required for deploying Liquid Data in an existing Weblogic/WLI/Workshop/etc domain. This JAR file is a Weblogic patch that fixes a Web service bug. Without it, Liquid Data generated Web services will throw the following exception message: java.lang.Error: NYI
Platform | All
Workaround | Add CR084935_70sp1_3.jar to your CLASSPATH before weblogic.jar before weblogic.jar. (When you install Liquid Data, the JAR fille CR084935_70sp1_3.jar is automatically copied to your system in <LD_HOME>/server/lib/ directory. You simply need to add it to your CLASSPATH to be able to deploy generated Web services.)
CR087708 | To grant Liquid Data administrative privileges to users, you must add each user individually to the LDAdmin group.
Problem | LDAdmin group members must be added as "users", not as "groups". For example, the steps in the following scenario would not give a user administrative privileges to on the Liquid Data Administration console. 1. Add ldsystem into the Administrators group 2. Add Administrators group as the members to the LDAmin When these users open the Liquid Data Administration Console, they will not get the Apply buttons indicating Administrative privileges.
Platform | All
Workaround | To grant LDAdmin group members administrative privileges in Liquid Data, add each user individually to the LDAdmin group.
CR088010 | Attempting to delete a stored query that does not have a .xq extension will cause a StringIndexOutOfBoundsException, and you will not be able to delete the query.
Problem | If you rename a stored query without specifying a .xq extension then attempt to delete the stored query, the Liquid Data Administration Console throws an exception (StringIndexOutOfBoundsException) and you will not be able to delete the query.
Platform | All
Workaround | Save all stored queries with appropriate .xq extension. If you have inadvertently renamed a stored query without the proper .xq extension, rename it with the .xq extension, and then delete it. (To get to the screen where you can rename a stored query, on the Administration Console click the Liquid Data node in left pane, click Repository tab, click stored_queries folder.)
CR090898 | A "JDBC pool connection leak" or "max open cursors exceeded" error messages are reported if an incorrect schema name is specified in a Liquid Data database data source definition.
Problem | If an invalid schema name is provided for a Liquid Data data source definition during data source configuration Liquid Data reports the following error messages: A JDBC connecton pool leak error message similar to the following: <Nov 13, 2002 7:55:40 PM CST> <Warning> <JDBC> <001074> <A JDBC pool connection leak was detected. A "max open cursors exceeded" error similar to the following: <Jun 25, 2002 3:03:49 PM PDT> <Error> <LiquidData> <000000> <arkets.xmediator.ad min.user - Query Execution Error (Run Time) 1-2-3-9: Problem while accessing relational database. (No Cursor Available)>
Platform | All
Workaround | If you encounter "JDBC connection leak" or "max open cursors exceeded" errors, verify that the database schema name you specified in the Administration Console is valid for a given data source. (For information about defining a schema for a database, see the figure Configuring a Liquid Data Source Description for a Relational Database and the accompanying table in the Administration Guide.) For example if you are using an Oracle database, the default schema name corresponds to the user name in upper case. So for an Oracle database identified as mydb/mydbpassword, the default schema associated with this user is MYDB. In Liquid Data relational database data source configuration, the schema name should be MYDB.
CR091015 | Problem in WebLogic Workshop with JNDI lookup of EJBs for creating EJB controls. This is caused by enabling Liquid Data in a WebLogic Platform domain.
Problem | If you have a WebLogic Platform domain enabled with Liquid Data and attempt to create a new EJB control in WebLogic Workshop, browsing the JNDI tree for the EJB will result in the following error message: WebLogic Workshop cannot find any JNDI entries for an Enterprise Java Bean. Please add an Enterprise Java Bean to your application server and try again.
Platform | All
Workaround | Two patches are available from BEA Customer Support to address this problem. Ask for the patches associated with the BEA WebLogic Workshop change request: CR091000. You need the following two jar files: CR091000_70sp1.jar is for the runtime. The jar file must be placed as the first entry in the classpath of the startweblogic script. CR091000_70sp1_workshop.jar is for the WebLogic Workshop development environment and must be placed in the /weblogic700/workshop folder. The cp entry in the winLaunch.cfg or the workshop.sh file must be updated to have this file as the first entry in the classpath. With this patch in place, WebLogic Workshop can find and display JNDI names of all EJBs deployed on the server including EJBs which have only local JNDI names.

Where to Get Liquid Data Product Documentation

Documentation for this product is available on an Online Documentation CD-ROM that ships with the product, and is also available on the Web at the BEA edocs documentation site at:

>     http://download.oracle.com/docs/cd/E13190_01/liquiddata/docs10/index.html

To access the PDFs on either platform, open the Liquid Data documentation Home page in a Web browser as described above, click the PDF files button, and select the document that you want to view or print. Alternatively, from within an HTML document, click the View as PDF link on the top navigation bar to open a PDF version of the currently displayed document.

If you do not have the Adobe Acrobat Reader, you can get it for free from the Adobe Web site at http://www.adobe.com/.