Queue and buffer settings

The probe uses a queue to store traps before processing them. Once processed, the probe puts the resulting alerts in a buffer ready to send to the ObjectServer. Use the information in this topic to set appropriate values for the properties that define the characteristics of the trap queue and the output buffer.

Trap queue

The trap queue holds SNMP traps that are waiting for processing by the probe. When an event storm occurs, this queue can grow quickly and consume excessive amounts of memory. To prevent this, you can use the TrapQueueMax property to specify a maximum size to which the queue can grow before the probe starts to discard traps.

It is important that you set TrapQueueMax to a value appropriate for your environment, Using a value that is too low causes traps to be lost. Using a value that is too large, consumes memory and that can effect the efficiency of the probe.

Determining the appropriate value for your environment may be an iterative process. You can use the probe's facilities for logging performance data to monitor the size of the queue over a period of time. From that you can determine a value for the size of the queue in normal operation and add in extra capacity to allow for extraordinary circumstances, without adversely affecting the efficiency of the probe. See Logging performance data for information on logging performance data.

Note: The TrapQueueMax property is set to 20000 by default. If the value is set to 0, the probe generates the following warning message: Memory growth of the probe is unbounded.

Buffer settings

Use the following properties to help improve the efficiency of sending alerts to the ObjectServer:

  • Buffering - When set to 1, this property instructs the probe to send alerts when the internal alert buffer has reached the size specified by the BufferSize property.
  • BufferSize - This property specifies the size of the buffer that the probe uses to store alerts before sending them to the ObjectServer.
  • FlushBufferInterval - This property specifies an interval in seconds that the probe waits before flushing the alerts to the ObjectServer. This property limits the time that alerts wait in the buffer when the buffer has yet to reach the size specified by the BufferSize property.