Monitor latency statistics using the CMC

Once you've enabled the recording of latency in record updates, the latency chain data is available in Liberator and can be accessed via JMX monitoring. You can view it using a JMX console, such as the Caplin Management Console (CMC). Here's how to do this with the CMC.

This feature is available in Liberator 6.2.7 and later.

When a liberator object has latency information recorded against it, you can view this data by examining the object's MBean attribute​ called latency-chain​ . The information's presented as a JSON map that contains latency data for a period (default 5 minutes) governed by the setting of the configuration item object-latency-stat-period  At the end of this period, the data is reset and the calculation (averaging) starts again.

The JSON map has the form:

{ "A->B" : { "min" : <min-millisec>, "max" : <max-millisec>, "avg" : <avg-millisec>, "count" : <count>} }

where A --> B identifies the hop to which the latency data applies. For example, datasource_X->Liberator_E is the hop where data for the object left the Integration Adapter called "datasource" (X for eXit) and entered the Liberator called "Liberator" (E for Entry).

  1. First set up your Integration Adapter(s), Transformer(s) and Liberator(s) to record latency information; see How can I... Record latency in record updates.
  2. Start the CMC (see step 3 in Installing the CMC).
  3. Double click on the Liberator box that's displayed in the initial CMC window and you should see a new CMC screen that shows the details of the Liberator and its connections to the other Platform components in your installation.

    For example:

Latency monitoring: CMC Detail view of Platform Components

  1. Select the Explorer tab, and in the MBean Explorer window at the top left, select the rttpd.cache.object entry. Drill down through the hierarchy to select the MBean for the object whose latency data you wish to view. For example, here's the Mbean for the object (in the test system we used) whose subject is /PLATYPUS/SUBSCRIBE/RECORD1

    The latency-chain attribute of the MBean contains the current latency information (highlighted in blue in the screenshot).

MBean detail showing latency-chain attrribute of a Liberator object


  1. Double click on the latency-chain attribute (anywhere on the line) to bring up the Attribute Viewer window:

CMC Attribute Viewer showing JSON content for latency-chain MBean attribute

You can now inspect the full JSON map containing the latency measurements, which in this example is:

{"<init>->datasource_X": { "min": "0", "max": "0", "avg": "0", "count": "2" }, "datasource_X->Liberator_E": { "min": "4", "max": "10", "avg": "7", "count": "2" }}

You can also select the text in the window and copy and paste it as required. 

See also: