JMX Adapter Service

Definition

All administrative functions of the AS Java and all the parameters watched by monitors are provided by MBeans. The JMX Adapter Service manages the configuration and lifecycle of the MBeanServer and provides access to it for applications, services, and libraries. On each node in the cluster (both types: dispatcher and server), a local MBeanServer is created. The local MBeanServers communicate with each other so that clients running inside the AS Java only have to interact with its local MBeanServer. Each local MBeanServer provides a virtual view of all MBeans in the cluster, i.e. a client can access MBeans regardless of whether they are registered locally or on a remote cluster node.

The JMX API itself is provided by the library SAP JMX Implementation, which is used by the JMX Adapter Service.

Structure

●      DefaultDomain: the value for the MBeanServer default domain

●      MessageTimeout: timeout for synchronous requests sent to an MBeanServer on a remote cluster node

·        NotificationQueue: within the AS Java JMX notifications are usually sent asynchronously. The notifications are queued and get processed by several worker-threads.

○       NotificationQueueMaxThreads: max. number of worker-threads that process the notification queue

○       NotificationQueueEnqTimeout: timeout for adding a new item to the notification queue

○       NotificationQueueThreadThreshold: number of notification queue items that cause the creation of a new worker thread

●      ObjectNameCompletion: JMX ObjectNames have to meet certain conventions. There is a factory which supports the creation of ObjectNames that include the necessary location information. The factory uses a cache to optimize the naming process.

○       ObjectNameCompletionCacheMinSize: initial cache size for ObjectName completion

○       ObjectNameCompletionCacheMaxSize: maximum cache size for ObjectName completion

Logging of the JMX Adapter Service

The JMX Adapter Service logs exceptions that could not be passed on to the client. Three kinds of exceptions are written to the log files:

●      Exceptions thrown within an MBean

●      Exceptions occurring at cluster internal communication

·        Exceptions that indicate insufficient privileges for MBeanServer operations

Integration

The log files are displayed in the LogViewer:

• System_Server_Log (Exceptions text)
• Service_JMX_trc (stack trace)