DB Connections (DPC2)

Description

This probe measures the current number of simultaneous connections to the database server. This number should be constant, an increase may indicate a connection leak in some subsystem. There is a maximum number of connections allowed. If that number is reached, service will be impacted.

Release notes

Show release notes
Version 1.2 - General deployment
  • Improvement: Changed the gui type to be able to define this on cluster level
  • Dependency:
    • escaux-nagios-plugins version 1.1+ on the BMS. Contact escaux to find out which version is installed.

Version 1.1 - Deprecated
  • Changed the gui type to be able to define this on cluster level
  • Dependency:
    • escaux-nagios-plugins version 1.1+ on the BMS. Contact escaux to find out which version is installed.

Version 1.0 - General deployment
  • Initial version
  • Dependency:
    • escaux-nagios-plugins version 1.1+ on the BMS. Contact escaux to find out which version is installed.

Resource configuration interface

GUI unavailable.

Resource parameters

This probe has no configurable parameters.

Performance graphs

This probe generates a graph with following performance metrics:

  • Total: the total number of concurrent database connections allowed by the database server. This value is fixed and is normally set to 100 for Database Server 1.x and 150 Database Server 2.X.
  • Used: the number of open database connections to at this point in time.
  • Free: (Free = Total - Used)

Alarms

This probe can report following alarm states:

  • WARNING: there are less than 50 database connections available.
  • CRITICAL: there are less than 5 database connections available.
  • UNKNOWN: the test could not be performed.

Possible causes

  • A high number of used database connections is typically caused by a "connection leak" in any process that opens and (normally) closes database connections
  • Failure to detect number of available database connections

Possible consequences

If there are no more database connections available, any process that requires to open a new connection to the database will fail. This includes:
  • Basic telephony using STARTDYNAMICAPPLICATION
  • The XML API
  • netConsole 3.x login, netDesktop 2.x

Possible actions

Following actions may be taken in response to a high or growing number of database connections:

  • Look at the performance graph, how the number of connections evolves over time.
    • If it is steadily growing, you can predict when it will reach 100% and as such determine the urgency.
    • If it is high (but not 100%), but constant, the situation is stable an currently not service affecting.
    • If it is at 100%, services are affected.
  • Restart the Communication Server process:
    • SOP Shell > Diagnostics > Telephony > Communication Server console > CLI> restart now

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