Lotus Domino Administrator 8 Help - Monitoring the database cache

PERFORMANCE

Monitoring the database cache
Monitor the effectiveness of the database cache by occasionally checking cache statistics. You can view the following statistics by viewing Mail & Database Statistic Reports or by using the server command:

Show Stat Database.DbCache.*

Statistic Description

Database.DbCache.CurrentEntries Number of databases currently in the cache. If this number frequently approaches the value of Database.DbCache.MaxEntries, increase the number of databases the cache can hold.

Database.DbCache.HighWaterMark Maximum number of databases in the cache during this running of the server program. This number may be artificially high because of startup activity, so it may not be a genuine indicator of cache performance.

Database.DbCache.Hits The number of times an "InitialDbOpen" is satisfied by finding the database in the cache. A high "hits-to-opens" ratio indicates that the database cache is working effectively. If the ratio is low, increase the number of databases the cache can hold.

Database.DbCache.InitialDbOpens The number of times a user/server opened a database that was not already being used by another user/server. For example, if a user opens a mail file while it is being used by the Replicator, this number does not increase. Compare this number to Database.DbCache.Hits to gauge the effectiveness of the cache.

Database.DbCache.Lookups The number of lookups to the database cache. A high "Database.DbCache.Hit" to "Database.DbCache.Lookups" ratio means the database cache is effective. If the ratio is low, increase the number of databases the cache can hold.

Database.DbCache.MaxEntries The number of databases the server can currently hold in its cache at once. To change this value, use the NOTES.INI file setting, NSF_DbCache_Maxentries, or increase physical memory.

Database.DbCache.OvercrowdingRejections Number of times a database is not placed into the cache when it is closed because Database.DbCache.CurrentEntries equals or exceeds Database.DbCache.MaxEntries times 1.5. This number should stay low. If it begins to rise, increase the number of databases the cache can hold.

See also

The database cache

Managing the database cache

Glossary

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Glossary

Statistic	Description
Database.DbCache.CurrentEntries	Number of databases currently in the cache. If this number frequently approaches the value of Database.DbCache.MaxEntries, increase the number of databases the cache can hold.
Database.DbCache.HighWaterMark	Maximum number of databases in the cache during this running of the server program. This number may be artificially high because of startup activity, so it may not be a genuine indicator of cache performance.
Database.DbCache.Hits	The number of times an "InitialDbOpen" is satisfied by finding the database in the cache. A high "hits-to-opens" ratio indicates that the database cache is working effectively. If the ratio is low, increase the number of databases the cache can hold.
Database.DbCache.InitialDbOpens	The number of times a user/server opened a database that was not already being used by another user/server. For example, if a user opens a mail file while it is being used by the Replicator, this number does not increase. Compare this number to Database.DbCache.Hits to gauge the effectiveness of the cache.
Database.DbCache.Lookups	The number of lookups to the database cache. A high "Database.DbCache.Hit" to "Database.DbCache.Lookups" ratio means the database cache is effective. If the ratio is low, increase the number of databases the cache can hold.
Database.DbCache.MaxEntries	The number of databases the server can currently hold in its cache at once. To change this value, use the NOTES.INI file setting, NSF_DbCache_Maxentries, or increase physical memory.
Database.DbCache.OvercrowdingRejections	Number of times a database is not placed into the cache when it is closed because Database.DbCache.CurrentEntries equals or exceeds Database.DbCache.MaxEntries times 1.5. This number should stay low. If it begins to rise, increase the number of databases the cache can hold.