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Changes in the db2hmon process in DB2 UDB Version 8.2

Question & Answer


Question

The db2hmon process has changed in DB2 Universal Database Version 8.2 and is no longer associated with the HEALTH_MON database manager configuration parameter.

Answer

In DB2® Universal Database™ (DB2 UDB) Version 8.1, the db2hmon process was controlled by the HEALTH_MON database manager configuration parameter. When HEALTH_MON was set to ON, a single-threaded independent coordinator process named db2hmon would start. This process would terminate if HEALTH_MON was set to OFF.

In DB2 UDB Version 8.2, the db2hmon process is no longer controlled by the HEALTH_MON database manager configuration parameter. Rather, it is a stand-alone process that is part of the database server so when DB2 is started, the db2hmon process starts. db2hmon is a special multi-threaded DB2FMP process that is named db2hmon on UNIX/Linux platforms and DB2FMP on Windows.

There are two main functions, health monitor and automatic maintenance, that run in the db2hmon process. The following outlines the activity that occurs in the db2hmon process:

  • If HEALTH_MON=ON, the health monitor starts and health indicators will be evaluated. Automatic maintenance evaluation will also occur to report the need for maintenance for any enable automatic maintenance health indicators (any of db.db_backup_req, db.tb_reorg_req, or db.tb_runstats_req).
  • If the appropriate AUTO_* database configuration parameter is set to ON, automatic maintenance evaluation will occur and automatic utilities will be run within the appropriate policy-defined maintenance windows.
  • If HEALTH_MON=OFF and all AUTO_* database configuration parameters are OFF, the db2hmon process will "wake-up" approximately every 2 hours to check for active databases. For any active database, the db2hmon process will connect, check the in-memory database configuration parameter settings for automatic maintenance, and disconnect.

Note that if the db2hmon process is manually terminated, it will automatically restart. It is a standard database server process that must always be running.

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Document Information

Modified date:
16 June 2018

UID

swg21221119