Sun Java System Application Server Enterprise Edition 8.1 2005Q2 High Availability Administration Guide

- Previous: Getting Device Information
- Next: Maintaining HADB Machines

## Getting Runtime Resource Information

The `hadbm resourceinfo` command displays HADB runtime resource information. You can use this information to help identify resource contention, and reduce performance bottlenecks. For details, see Tuning HADB in Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Performance Tuning Guide.

The command syntax is:

    hadbm resourceinfo  [--databuf]  [--locks]  [--logbuf]  [--nilogbuf]
    [--adminpassword=password | --adminpasswordfile=file]
    [--agent=maurl]
    [dbname]

The dbname operand specifies the database name. The default is `hadb`.

The following table describes the `hadbm resourceinfo` special command options. See General Options for a description of other command options.

For more information, see hadbm-resourceinfo(1).

Table 3–15 hadbm resourceinfo Command Options

Option | Description
--- | ---
--databuf -d | Display data buffer pool information. See Data Buffer Pool Information below for more information.
--locks -l | Display lock information. See Lock Information below for more information.
--logbuf -b | Display log buffer information. See Log Buffer Information below for more information.
--nilogbuf -n | Display node internal log buffer information. See Node Internal Log Buffer Information below for more information.

### Data Buffer Pool Information

Data buffer pool information contains the following:

- `NodeNo`: Node number.

- `Avail`: Total space available in the pool, in MBytes.

- `Free`: Free space available, in MBytes.

- `Access`: Cumulative number of accesses to the data buffer from database, from start until now.

- `Misses`: Cumulative number of page faults that have occurred from database start until now.

- `Copy-on-Write`: Cumulative number of pages copied internally in the data buffer due to checkpointing.

When a user transaction performs an operation on a record, the page containing the record must be in the data buffer pool. If it is not, a `miss` or a page fault occurs. The transaction then has to wait until the page is retrieved from the data device file on the disk.

If the miss rate is high, increase the data buffer pool. Since the misses are cumulative, run `hadbm resourceinfo` periodically and use the difference between two runs to see the trend of miss rate. Do not be concerned if free space is very small, since the checkpointing mechanism will make new blocks available.

##### Example 3–17 Example data buffer pool information

For example:

    NodeNO Avail Free Access Misses Copy-on-Write
    0 256 128 100000 50000 10001 256 128 110000 45000 950

### Lock Information

Lock information is as follows:

- `NodeNo`: Node Number.

- `Avail`: Total number of locks available on the node.

- `Free`: Number of free locks.

- `Waits`: Number of transactions waiting to acquire locks. This is cumulative.

One single transaction cannot use more than 25% of the available locks on a node. Therefore, transactions performing operations in large scale should be aware of this limitation. It is best to perform such transactions in batches, where each batch must be treated as a separate transaction, that is, each batch commits. This is needed because read operations running with `repeatable read` isolation level, and `delete`, `insert`, and `update` operations use locks that are released only after the transaction terminates.

To change the `NumberOfLocks`, see Clearing and Archiving History Files

##### Example 3–18 Example lock information

For example:

    NodeNO Avail Free Waits
    0 50000 20000 101 50000 20000 0

### Log Buffer Information

Log buffer information is:

- `NodeNo`: Node Number

- `Available`: amount of memory allocated for the log buffer in MB

- `Free`: amount of free memory in MB

Do not worry if free space is very small, since HADB starts compressing the log buffer. HADB starts compression from the head of the ring buffer and performs it on consecutive log records. Compression cannot proceed when HADB encounters a log record that has not been executed by the node and received by the mirror node

##### Example 3–19 Example of log buffer information

For example:

    NodeNO Avail Free
    0 16 21 16 3

### Node Internal Log Buffer Information

Node internal log buffer information is:

- Node Number

- Available: amount of memory allocated for the log device in MB

- Free: amount of free memory in MB

##### Example 3–20 Example of internal log buffer information

For example:

`NodeNO Avail Free`

`0 16 21 16 3`

- Previous: Getting Device Information
- Next: Maintaining HADB Machines

- © 2010, Oracle Corporation and/or its affiliates