Recommended Settings for DBM CFG Parameters
DB2® default installation manages all the memory automatically. You do not have to set values explicitly for these parameters INSTANCE_MEMORY, FCM_NUM_BUFFERS, and FCM_NUM_CHANNELS.
Enabling the following monitor switches is recommended in production:
| Parameter | Mandatory or Recommended | Recommended Value |
|---|---|---|
| DFT_MON_BUFPOOL | Recommended | ON |
| DFT_MON_LOCK | Recommended | ON |
| DFT_MON_SORT | Recommended | ON |
| DFT_MON_STMT | Recommended | ON |
| DFT_MON_TABLE | Recommended | ON |
| DFT_MON_TIMESTAMP | Recommended | ON |
| DFT_MON_UOW | Recommended | ON |
| MON_HEAP_SZ | Recommended | AUTOMATIC |
| MAXAGENTS | Recommended |
Limits the number of database manager agents (both coordinator or subagents) that can run concurrently. Pick a high enough number so that the combined connection requirements from the application servers, agents, monitoring tools, and so on do not exceed the MAXAGENTS limit during peak processing periods. If you do, you must restart the DB2 instance to increase this limit. Recommend value: Must be greater than the number of connections needed by Sterling B2B Integrator (that is, the sum of transactional (local) plus NoTrans pools in jdbc.properties file) plus the connections needed by operational management tools. With the use of connection pooling in the NoApp Server, the number of database connections is less than the number of users who are logged in. Depending on your anticipated peak workload traffic, this parameter may range from a small number such as 25 to a large number in the thousands. Monitor the number of concurrent connections in production (especially during peak periods) to ensure that it does not reach the maximum. When the MAXAGENTS limit is reached, DB2 refuses to establish new connection requests. |
Estimation Guidelines for Number of Connections
You can roughly estimate the number of concurrent user connections required for Sterling B2B Integrator with this formula:
Concurrent (DB2) connections = A + B + C + D
| Variable | Description |
|---|---|
| A | Maximum number of UI-based connections |
| B | Maximum NoApp Server connection pool max size times the number of NoApp Server instances (as in a cluster) |
| C | Any additional connections that are opened by customized code or user exits that do not go through the NoApp Server connection pools. This connection requirement is specific to your implementation. |
| D | Number of connections required by the containers. |
Benchmarking
Benchmarking your system to validate assumptions and estimates prior to a production implementation is strongly recommended. During the test, monitor the connection pool usage levels in each of the application server instances, the number of agents to run to meet your processing and service levels, and the actual DB2 database connections established.