Inspecting Vespa Java Services

JConsole

Determine the state of each running Java Vespa service using JConsole. JConsole is distributed along with the Java developer kit. It can be started as follows:

$ jconsole <host>:<port>
where the host and port determine which service to attach to. For security purposes the JConsole tool can not directly attach to Vespa services from external machines.

Connecting to a Vespa instance

To attach a JConsole to a Vespa service running on another host, create a tunnel from the JConsole host to the Vespa service host. This can for example be done by setting up two SSH tunnels as follows:

$ ssh -N -L<port1>:localhost:<port1> <service-host> &
$ ssh -N -L<port2>:localhost:<port2> <service-host> &
where port1 and port2 are determined by the type of service (see below). A JConsole can then be attached to the service as follows:
$ jconsole localhost:<port1>
Port numbers:
Service Port 1 Port 2
QRS 19015 19016
Docproc 19123 19124
Updated port information can be found by running:
$ vespa-model-inspect service <servicename>
where the resulting RMIREGISTRY and JMX lines determine port1 and port2, respectively.

Examining thread states

The state of each container is available in JConsole by pressing the Threads tab and selecting the thread of interest in the threads list. Threads of interest includes search, connector, closer, transport and acceptor (the latter four are used for backend communications):

Thread states in JConsole.