Performance Tuning for Content Manager

202 Performance Tuning for Content Manager

Figure 8-1 shows an example of a simple IBM Lotus 1-2-3® spreadsheet using

the snapshot elements to compute the buffer pool ratios.

Figure 8-1 Lotus 1-2-3 spreadsheet

If your server exceeds 1 GB RAM, consider increasing the default database

buffer pool sizes. This can improve performance for heavy loads. To see whether

increasing the buffer pool sizes could help, monitor buffer pool logical and

physical reads for both data and indexes as mentioned earlier; also monitor

committed memory and buffer pool hit ratios. In general, keep the total of all

buffer pools below 50% of total physical memory, and even less if a Resource

Manager or middle-tier server shares the same machine.

8.6 Parameter tuning

There are two types of DB2 configuration parameters that are typically the

subject of tuning: database manager (instance) and database. This section

provides a discussion of some of the more important of these configuration

parameters that you can tune to improve Content Manager performance. Each

parameter is discussed in detail, along with its default value and our

recommendation as to what the value should be set to based on our

experiences. Keep in mind that these are only recommendations and that your

specific system environment might require different values based on your tuning.

For each parameter, the type of parameter (dbm or db) as well as the relative

performance impact is provided:

High Can have a significant impact on performance.

Medium Can have some impact on performance.

Low Has a less general or less significant impact on performance.

Table 8-1 on page 203 lists in order the configuration parameters discussed in

this section.

Chapter 8. Tuning DB2 for Content Manager 203

Table 8-1 Configuration parameter table

Long name Short name Impact

Intra-partition parallelism INTRA_PARALLEL DBM - High

Maximum number of concurrently

active databases

NUMDB DBM - Low

Maximum number of active applications MAXAPPLS DB - Medium

Average number of active applications AVG_APPLS DB - Low

Maximum number of database

manager agents

MAXAGENTS DBM - Medium

Maximum number of client connections MAX_CONNECTIONS DBM - Medium

Maximum number of coordinating

agents

MAX_COORDAGENTS DBM - Medium

Initial number of agents in pool NUM_INITAGENTS DBM - Medium

Agent pool size NUM_POOLAGENTS DBM - High

Maximum number of fenced processes FENCED_POOL DBM - Medium

Keep fenced process KEEPFENCED DBM - Medium

Initial number of fenced processes NUM_INITFENCED DBM - Medium

Maximum database files open per

application

MAXFILOP DB - Medium

Maximum total files open MAXTOTFILOP DBM - Medium

Database heap DBHEAP DB - Medium

Catalog cache size CATALOGCACHE_SZ DB - High

Package cache size PCKCACHESZ DB - High

Log buffer size LOGBUFSZ DB - High

Maximum storage for lock list LOCKLIST DB - High

Application control heap size APP_CTL_HEAP_SZ DB - Medium

Application heap size APPLHEAPSZ DB - Medium

Sort heap size SORTHEAP DB - High

Sort heap threshold SHEAPTHRES DBM - High

Statement heap size STMTHEAP DB - Medium

204 Performance Tuning for Content Manager

You can tune some or all of the following parameters during the initial installation

of your Content Manager system. We also recommend maintenance tuning on a

regular basis to ensure that performance does not degrade over time. Many of

the parameters can be tuned without having to turn off your system. Remember

the general performance tuning guideline: change one parameter at a time.

Changing database manager configuration parameters

Use this generic procedure to retrieve and update database manager (DBM)

configuration parameters. The specific update command appears in the

respective parameters subsection.

Query heap size QUERY_HEAP_SZ DBM - Medium

Java interpreter heap size JAVA_HEAP_SZ DBM - High

Private memory threshold PRIV_MEM_THRESH DBM - Medium

Client I/O block size RQRIOBLK DBM - Medium

Application support layer heap size ASLHEAPSZ DBM - High

Changed pages threshold CHNGPGS_THRESH DB - High

Number of asynchronous page

cleaners

NUM_IOCLEANERS DB - High

Number of I/O servers NUM_IOSERVERS DB - High

Maximum percent of lock list before

escalation

MAXLOCKS DB - High

Lock timeout LOCKTIMEOUT DB - Medium

Size of the log files LOGFILSIZ DB - Medium

Number of primary logs LOGPRIMARY DB - Medium

Number of secondary log files LOGSECOND DB - Medium

Minimum commits before write logs to

disk

MINCOMMIT DB - High

Connection concentrator MAX_CONNECTIONS

MAXAGENTS

NUM_INITAGENTS

NUM_INITFENCED

MAX_COORDAGENTS

NUM_POOLAGENTS

DBM -

Medium/High

Long name Short name Impact