Apama 10.15.0 | Deploying and Managing Apama Applications | Correlator Utilities Reference | Inspecting correlator state
 
Inspecting correlator state
The engine_inspect tool lets you inspect the state of a running correlator. This means you can review the applications loaded and running on a correlator. The executable for this tool is located in the bin directory of the Apama installation. Running the tool in the Apama Command Prompt or using the apama_env wrapper (see Setting up the environment using the Apama Command Prompt) ensures that the environment variables are set correctly.
Synopsis
To inspect applications on a running correlator, run the following command:
engine_inspect [ options ]
When you run this command with the –h option, the usage message for this command is shown.
Description
The engine_inspect tool retrieves state information from a running correlator and sends it to stdout. By default, the tool outputs information on the monitors, JMon applications, event types and container types currently injected in a correlator.
Note:
Apama's in-process API for Java (JMon) is deprecated and will be removed in a future release.
You can filter this list by specifying command-line options. When you specify one or more of the -m, -j, -e, -t, -x, -P, or -R options, the engine_inspect tool displays only the information indicated by the option(s) you specify. See the table below for more information on these options.
Options
The engine_inspect tool takes the following options:
Option
Description
-m | --monitors
Displays the names of all EPL monitors in the correlator and the number of monitor instances each monitor has spawned.
-j | --java
Displays the names of all JMon applications in the correlator and the number of event listeners each JMon application has created.
Note:
Apama's in-process API for Java (JMon) is deprecated and will be removed in a future release.
-e | --events
Displays the names of all event types in the correlator and the number of templates of each type, as defined in listener specifications. This includes each event template in an on statement and each stream source template, for example, stream<A> := all A().
For more information about event types and listeners, see Introduction to Apama Event Processing Language.
-t | --timers
Displays the current EPL timers active within the system. The four types of timers which may be displayed here are wait, within, at, and stream. The stream timers are those set up to support the operation of a stream network.
-x | --contexts
Displays the names of any user-defined contexts, how many monitor instances are running in each context, what channels each context is subscribed to, and how many entries are on each context's input queue.
-a | --aggregates
Displays a list of the custom (user-defined) aggregate functions that have been injected. You use aggregate functions in stream queries. Apama built-in aggregate functions are not listed.
-P | --pluginReceivers
Displays the names of any plug-in receivers, the channels the plug-in is subscribed to, and the number of items on the plug-in's input queue. A plug-in receiver is an EPL plug-in that is subscribed to one or more channels.
-R | --receivers
Displays the names of any external receivers, each receiver's address, the channels each receiver is subscribed to, and the number of entries on each receiver's output queue.
-r | --raw
Indicates that you want raw output, which is more suitable for machine parsing. Raw output provides the name of each entity in the correlator followed by the number of instances associated with that entity. For a monitor, you get the number of its monitor instances. For a JMon application, you get the number of its listeners. For an event type, you get the number of its templates. For example:
com.apama.samples.stockwatch.StockWatch 1
Tick 1
-h | --help
Displays usage information.
-n host | --hostname host
Name of the host on which the correlator is running. The default is localhost. Non-ASCII characters are not allowed in host names.
-p port | --port port
Port on which the correlator is listening. The default is 15903.
-v | --verbose
Displays process names and versions in addition to application information. Optional. The default is to display only application information.
-V | --version
Displays version information for the engine_inspect tool.
Exit status
The engine_inspect tool returns the following exit values:
Value
Description
0
All status requests were processed successfully.
1
No connection to the correlator was possible or the connection failed.
2
Other error(s) occurred while requesting/processing status.