Performance tuning with the Configuration Tool

To run the Performance Tuning tool with the Configuration Tool:

1. In the Configuration Tool, click Performance tuning in the task list on the left. The Performance tuning: administrator input window opens.

   Use this window to provide information that the Performance Tuning tool will use to calculate the following settings for the directory server instance:

   • Entry cache size
   • Filter cache size
   • Group Member Cache size
   • Group Member Cache Bypass Limit
   • DB2® LDAPDB buffer pool size
   • DB2 IBMDEFAULTDB buffer pool size
   Notes:
   1. The Performance Tuning tool backs up the ibmslapd.conf file and saves it in the logs/ibmslapd.conf.save file in the directory for this directory server instance.
   2. The information you provide is logged in the logs/perftune_input.conf file in the directory for this directory server instance.

   Additionally, if the directory server instance has been running for some time and a substantial amount of database activity has occurred, the tool monitors the performance of the directory server instance and displays database "health check" information about the following DB2 parameters:

   • DB2 NUM_IOSERVERS
   • DB2 NUM_IOCLEANERS
   • CATALOGCACHE_SZ
   • PCKCACHESZ
   • LOGFILSIZ
   • LOCKLIST
2. Type the percentage of system memory you want allocated to this directory server instance in the Percentage of available system memory to be allocated to this directory instance field. This allows available system memory to be divided between multiple instances of Tivoli Directory Server, or between Tivoli Directory Server and other servers you plan to run on this system. This information will be used for calculating the sizes of the entry and filter caches.
3. In the Planned number of groups field, type the estimated number of groups in the directory server instance. This information will be used for calculating sizes for the directory server caches.
4. In the Maximum number of members in a group that will be referenced frequently field, type the average number of members for groups that will be referenced frequently.
5. In the Number of entries and average entry size section, do one of the following:
   • If you want to estimate the number of entries in the directory and the average size of an entry, do the following:
     1. In the Planned number of entries field, type your estimate of the total number of entries planned for the directory server instance. The Performance Tuning tool attempts to discover the number of entries in the directory server instance. If it cannot, it uses a default of 10,000 entries. This information will be used for calculating sizes for the directory server caches.
     2. In the Average size of an entry (Bytes) field, type the estimated average size of an entry in the directory server instance. The Performance Tuning tool attempts to compute the size of an entry in the directory server instance. If it cannot, it uses a default of 2650 bytes. This information will be used for calculating sizes for the directory server caches.
   • If you want the Configuration Tool to obtain the total number of entries and average entry size for you, click Load from server instance database. The Configuration Tool will complete the Planned number of entries and Average size of an entry (Bytes) fields.
6. In the Update frequency section, click one of the following:
   • Frequent updates expected if there will be frequent updates to the directory server instance. (As a guideline, an average of more than one update for every 500 searches would be considered frequent updates.)
   • Batch updates if you expect less frequent updates or if updates are grouped and made at certain times during the day.

   This information is used to set the filter cache size. The filter cache is useful only when there are infrequent updates to the directory and the same searches are run more than once. If frequent updates are expected, the filter cache will be set to 0. If infrequent or batch updates are expected, the filter cache will be set to 1024 filter cache entries.

7. If you want the tool to provide the most thorough performance analysis, select the Enable collection of additional system data for extended tuning check box. The Performance Tuning tool will run for 5 minutes and collect and analyze data about the directory server instance, and then make recommendations about the settings for the following DB2 parameters in addition to the settings recommended when you do not enable extended tuning:
   • SORTHEAP
   • MAXFILOP
   • DBHEAP
   • CHNGPGS_THRESH
   • NUM_IOSERVERS
   • NUM_IOCLEANERS

   Recommendations for these DB2 parameters are provided in the perftune_stat.log file for the directory server instance.

   Notes:
   1. The directory server instance must have been running for some time before there will be enough DB2 data available to do the database health check analysis and make any recommendations for these settings.
   2. Selecting this check box enables the DB2 monitor switches BUFFERPOOL and SORTHEAP. The performance of the directory server instance is likely to degrade while these switches are enabled and the data is being collected.
   3. To get accurate data for the best tuning for your directory server instance, select the Enable collection of additional system data for extended tuning check box during a time when directory activity is typical for your environment. Running the database health check when the directory server is less busy than usual does not result in optimum performance recommendations.
8. Click Next. The Performance tuning: verification window opens. Use this window to verify that you want to use the performance tuning settings calculated by the Performance Tuning tool. You can also use this window to tune database parameters.
9. Inspect the settings recommended by the tool.

   The Database health status table is not completed if this is a new directory server instance with no database activity yet. The table is completed if the Performance Tuning tool has collected information about at least one DB2-related parameter. The information is also logged in the perftune_stat.log file.

   If the database is populated and has had enough activity, information about the following DB2 parameters is displayed:

   • DB2 NUM_IOSERVERS
   • DB2 NUM_IOCLEANERS
   • CATALOGCACHE_SZ
   • PCKCACHESZ
   • LOGFILSIZ
   • LOCKLIST

   If you selected the Enable collection of additional system data for extended tuning check box on the Performance tuning: administrator input window, information about the following DB2 parameters is also displayed:

   • SORTHEAP
   • MAXFILOP
   • DBHEAP
   • CHNGPGS_THRESH
   • NUM_IOSERVERS
   • NUM_IOCLEANERS

   The health status displayed for the DB2 parameters can be one of the following:

   • OK
   • Increase
   • Decrease
   • Not Collected

   Parameters not analyzed have a health status of Not Collected.

   Use the information to decide which DB2 parameters you can tune to obtain better performance.

10. To modify the values of database parameters, click Tune database parameters to display the Database input panel. On the Database input panel you can specify values for the following database parameters:

    Database heap

    The maximum memory to be used by database heap. The database heap contains control block information for tables, indexes, table spaces, and buffer pools. It also contains space for the log buffer and temporary memory used by utilities.

    Package cache size

    Used for caching of sections for static and dynamic SQL and XQuery statements on a database.

    Log buffer size (Pages)

    The size of the buffer allocated for log records. Specify the amount of the database heap to use as a buffer for log records.

    Maximum database files open per application

    The maximum number of file handles that can be open for each database agent.

    Changed pages threshold (Percentage)

    The level (percentage) of changed pages.

    Sort heap size (Pages)

    The maximum number of private memory pages to be used for private sorts, or the maximum number of shared memory pages to be used for shared sorts.

    Log file size (KB)

    The size to be allocated for the log files. This parameter defines the size of each primary and secondary log file.

    Database log path

    The location where you want the log files to be stored. You can click Browse to find the location.

    Click OK to save your selections and update the database parameters to the values specified. Any parameters you do not specify will be set to default values.
11. Do one of the following:
    • If you want to update the settings for your directory server instance to the settings recommended in the Calculated directory cache sizes and Calculated database buffer pool sizes boxes, click Yes, use the recommended values to update the directory and database configuration settings.
    • If you do not want to use the settings recommended, click No, keep the current settings. When you click Finish, no configuration settings will be updated. Your current settings will be kept.
12. Click Finish.

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