Event publisher parameters

OMEGAMON® Data Connect event publisher parameters control aspects of internal OMEGAMON Data Connect processing.

    queue-capacity: <number_of_records>
The maximum number of records in the queue for each output of OMEGAMON Data Connect.

Default: 50000 (fifty thousand).

Each output of OMEGAMON Data Connect, including each TCP sink and each HTTP endpoint, has its own internal queue.

If a queue reaches capacity:

  • The queue rejects (drops) any new incoming records until the queue falls within capacity.
  • OMEGAMON Data Connect reports the warning message KAYC0084W.

OMEGAMON Data Connect continues to read incoming records, even if all queues are at capacity.

Queue capacity affects the required maximum heap size (-Xmx) of the Java™ virtual machine that runs OMEGAMON Data Connect.

Attention: If the storage required for all records referred to by all queues exceeds the maximum heap size, OMEGAMON Data Connect shuts down with an out-of-memory condition.

Calculating queue capacity (a number of records) for a given maximum heap size (a number of bytes), or vice versa, is not straightforward:

  • The storage, in bytes, depends on the length of each record. Different record types have different lengths.
  • The mixture of record lengths can vary over time and depends on site-specific factors such as the OMEGAMON attributes involved and their collection intervals.
  • The number of records in each queue can vary over time depending on site-specific factors such as data volume and the processing speed of each destination.

In practice, the default queue capacity of fifty thousand records meets typical requirements, and fits within the maximum heap size of 4096 MB that is set in the supplied sample files for running OMEGAMON Data Connect.