Servlet session counters
Use this page as a reference for properties of servlet session counters.
Data counters for this category contain usage information for HTTP sessions.
Counter definitions
Name | Key | ID | Description | Granularity | Type | Level | Overhead |
---|---|---|---|---|---|---|---|
CreateCount | servletSessionsModule.createdSessions | 1 | The number of sessions that were created | Per web application | CountStatistic | All | Low |
InvalidateCount | servletSessionsModule.invalidatedSessions | 2 | The number of sessions that were invalidated | Per web application | CountStatistic | All | Low |
LifeTime | servletSessionsModule.sessionLifeTime | 4 | The average session life time in milliseconds (time invalidated - time created) | Per web application | TimeStatistic | Extended | Medium |
ActiveCount | servletSessionsModule.activeSessions | 6 | The number of concurrently active sessions. A session is active if the WebSphere® Application Server is currently processing a request that uses that session. | Per web application | RangeStatistic | All | High |
LiveCount | servletSessionsModule.liveSessions | 7 | The number of local sessions that are currently cached in memory from the time at which this metric is enabled. | Per web application | RangeStatistic | Basic | High |
NoRoomForNewSessionCount | servletSessionsModule.noRoomForNewSession | 8 | Applies only to session in memory with AllowOverflow=false. The number of times that a request for a new session cannot be handled because it exceeds the maximum session count. | Per web application | CountStatistic | Extended | Low |
CacheDiscardCount | servletSessionsModule.cacheDiscards | 9 | The number of session objects that have been forced out of the cache. A least recently used (LRU) algorithm removes old entries to make room for new sessions and cache misses. Applicable only for persistent sessions. | Per web application | CountStatistic | All | Low |
ExternalReadTime | servletSessionsModule.externalReadTime | 10 | The time (milliseconds) taken in reading the session data from the persistent store. For multirow sessions, the metrics are for the attribute; for single row sessions, the metrics are for the entire session. Applicable only for persistent sessions. When using a JMS persistent store, you can choose to serialize the replicated data. If you choose not to serialize the data, the counter is not available. | Per web application | TimeStatistic | Extended | Medium |
ExternalReadSize | servletSessionsModule.externalReadSize | 11 | Size of the session data read from persistent store. Applicable only for (serialized) persistent sessions; similar to external Read Time. | Per web application | TimeStatistic | Extended | Medium |
ExternalWriteTime | servletSessionsModule.externalWriteTime | 12 | The time (milliseconds) taken to write the session data from the persistent store. Applicable only for (serialized) persistent sessions. Similar to external Read Time. | Per web application | TimeStatistic | Extended | Medium |
ExternalWriteSize | servletSessionsModule.externalWriteSize | 13 | The size of the session data written to persistent store. Applicable only for (serialized) persistent sessions. Similar to external Read Time. | Per web application | TimeStatistic | Extended | Medium |
AffinityBreakCount | servletSessionsModule.affinityBreaks | 14 | The number of requests that are received for sessions that were last accessed from another web application. This value can indicate failover processing or a corrupt plug-in configuration. | Per web application | CountStatistic | All | Low |
TimeSinceLastActivated | servletSessionsModule.timeSinceLastActivated | 15 | The time difference in milliseconds between previous and current access time stamps. Does not include session time out. | Per web application | TimeStatistic | All | Medium |
TimeoutInvalidationCount | servletSessionsModule.invalidatedViaTimeout | 16 | The number of sessions that are invalidated by timeout. | Per web application | CountStatistic | All | Low |
ActivateNonExistSessionCount | servletSessionsModule.activateNonExistSessions | 17 | The number of requests for a session that no longer exists, presumably because the session timed out. Use this counter to help determine if the timeout is too short. | Per web application | CountStatistic | All | Low |
SessionObjectSize | servletSessionsModule.serializableSessObjSize | 18 | The size in bytes of (the serializable attributes of ) in-memory sessions. Only session objects that contain at least one serializable attribute object is counted. A session can contain some attributes that are serializable and some that are not. The size in bytes is at a session level. | Per web application | TimeStatistic | All | Max |