See: Description
| Package | Description |
|---|---|
| com.lightstreamer.jmx |
Javadoc-like description of the MBeans available through Lightstreamer JMX interface.
Each of the documented interface classes represents a type of MBeans; one or more instances of each MBean type may be hosted by the JMX server. See in the introduction for each interface class the name or the name pattern by which the MBean instances of that type are registered in the JMX server.
Note that each documented "getXxxxx" method without arguments represents a property named "Xxxxx"
in an MBean instance of the related type; the property is read-only, unless a
corresponding "setXxxxx" method is also documented.
All other documented methods represent operations that can be invoked on an MBean instance of the related type.
The MBeans cover various aspects of the Server activity. The following is a resume of the role of each MBean type. For more detailed descriptions see the introduction for each related interface class.
ServerMBean contains information on the Server process context and configuration. It also provides metrics on the overall state of health of the Server and some runtime settings that can pose limitations on the overall activity.EditionDetailsMBean reports the kind of license in use and all the capabilities allowed and disallowed by license terms.ResourceMBean provides statistics about the client connections and requests and the consequent sessions and subscriptions handled. It reports the connections and requests aggregated for many of their characteristics.ServerSocketMBean's are one for each server port configured, and provide statistics about client connections, similarly to the ResourceMBean, but restricted to their port.StreamMBean provides statistics about the overall data push activity, counting events received from the Data Adapters, sent to the clients and also not sent, as conflated or lost. It also covers client "sendMessage" activity.PushNotificationsMBean covers the Mobile and Web Push Notification service, with activity statistics and a few runtime control operations.SessionMBean's are one for each client session currently active and report session characteristics. They also provide statistics on requests and data push activity, similarly to other MBeans, but restricted to their session.SessionMBean's can grow to a very large number, they have to be enabled through static configuration. When not enabed, a single MBean named FakeSession is present instead, as a reminder.AdapterSetMBean's are one for each Adapter Set configured, and mainly advise on queues of pending invocations to their Metadata Adapter (provided that specific thread pools are configured).DataAdapterMBean's are one for each Data Adapter configured among the various Adapter sets, and mainly provide statistics on subscriptions and data push activity, similarly to other MBeans, but restricted to their Data Adapter.LoadMBean reports the current load of the system, mainly in terms of queues of pending tasks on the various thread pools. A few other metrics that can indicate load issues are provided.ThreadPoolMBean's are one for each thread pool used internally by the Server to allocate most of the processing. They provide statistics on the current activity and the current state of the threads for their pool.For many of the metrics considered in the various MBeans, the provided statistics can be of various types; for instance:
With reference to the above cases, statistics that report the current frequency of some underlying metric (for instance, the frequency of events from a Data Adapter) are computed with reference to predefined sampling periods.
In fact, the execution time is divided into a sequence of sampling periods, whose length is configured through the <collector_millis> configuration setting.
In practice, for each sampling period, all the underlying metrics are counted (in our example, the number of events from a Data Adapter);
then, at the end of the period, the counts are divided by the period length, to find all the per-second rates;
these figures are then reported upon all inquiries of the frequency statistics, until the next sampling period terminates and new updated values are available.
Similarly, statistics that report the "new" occurrences of some metric refer to the number of occurrences counted in the last completed sampling period.
Edition Note: JMX manageability is an optional feature, available depending on Edition and License Type and may not be available at all with some License Types.
When not available, the JMX interface is still accessible, but only the ServerMBean is present and, moreover, it only offers a shutdown operation.
To know what features are enabled by your license, please see the License tab of the Monitoring Dashboard.