Details

    • Type: Explanation
    • Status: Obsolete
    • Affects Version/s: EXASolution 5.0, EXASOL 6.0.0, Exasol 6.1.0
    • Fix Version/s: None
    • Component/s: EXASolution
    • Labels:
      None
    • Explanation:
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      Note: This solution is no longer maintained. For the latest information, please refer to our documentation:

      https://docs.exasol.com/database_concepts/session_management.htm

       

      EXASolution is able to handle 10.000 sessions per node. These sessions can be either active or inactive.
      Session is defined as active if matches at least one of the following conditions:

      • doing login authorization
      • doing query execution
      • has open transaction
      • has open prepared statement
      • has open resultset
      • has open subconnection

      Each active session occupies one active slot. The number of the active slots is limited per default to 100 (globally, not per node). In inactive to active transition the session may wait for active slot to becomes available. In such case the status QUEUED will be shown for all waiting sessions in the STATUS column of EXA_*SESSIONS. All waiting for _active slot sessions are served in FIFO manner.

      Since EXASolution 5.0.11 there are 100 additional active but blocked session slots available for sessions that are waiting for another session. Typically they are waiting for commit and have status "Waiting for session" in the ACTIVITY column of EXA_*_SESSIONS. If the number of the blocked sessions exceeds the
      active but blocked session slots count then the remaining free active slots are used for them (see EXASOL-1531).

      Since EXASolution 5.0.12 an EXAoperation warning is generated if 80% of the maximum allowed active session slots are in use:

      Query queue limit of active sessions nearly reached, 
      running: <<active_sessions>> of 100 (+ <<blocked_sessions>> WAIT FOR COMMIT) are in use. 
      Total number of sessions: <<all_sessions>>.
      

      If a login request can't be processed and has to wait because no free active session slots are available, an EXAoperation warning will be periodically logged until all requests have been processed:

      Limit of active sessions has been reached.
      


      Note: Before EXASolution 5.0 a session is counted always as active after setting AUTOCOMMIT OFF. In order to free the used active session slot, an explicit COMMIT needs to be done right after the AUTOCOMMIT OFF command.

      Show
      Note: This solution is no longer maintained. For the latest information, please refer to our documentation: https://docs.exasol.com/database_concepts/session_management.htm   EXASolution is able to handle 10.000 sessions per node. These sessions can be either active or inactive. Session is defined as active if matches at least one of the following conditions: doing login authorization doing query execution has open transaction has open prepared statement has open resultset has open subconnection Each active session occupies one active slot . The number of the active slots is limited per default to 100 (globally, not per node). In inactive to active transition the session may wait for active slot to becomes available. In such case the status QUEUED will be shown for all waiting sessions in the STATUS column of EXA_* SESSIONS. All waiting for _active slot sessions are served in FIFO manner. Since EXASolution 5.0.11 there are 100 additional active but blocked session slots available for sessions that are waiting for another session. Typically they are waiting for commit and have status "Waiting for session" in the ACTIVITY column of EXA_*_SESSIONS. If the number of the blocked sessions exceeds the active but blocked session slots count then the remaining free active slots are used for them (see EXASOL-1531 ). Since EXASolution 5.0.12 an EXAoperation warning is generated if 80% of the maximum allowed active session slots are in use: Query queue limit of active sessions nearly reached, running: <<active_sessions>> of 100 (+ <<blocked_sessions>> WAIT FOR COMMIT) are in use. Total number of sessions: <<all_sessions>>. If a login request can't be processed and has to wait because no free active session slots are available, an EXAoperation warning will be periodically logged until all requests have been processed: Limit of active sessions has been reached. — Note: Before EXASolution 5.0 a session is counted always as active after setting AUTOCOMMIT OFF . In order to free the used active session slot , an explicit COMMIT needs to be done right after the AUTOCOMMIT OFF command.
    • Category 1:
      Database Administration
    • Category 2:
      Clients, Interfaces & Drivers

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            • Assignee:
              CaptainEXA Captain EXASOL
              Reporter:
              CaptainEXA Captain EXASOL
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                Updated:
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