Wednesday, 6 December 2017

WebSphere Liberty Profile - Monitoring via JMX over REST using Jython

For this, I'm using two excellent IBM developerWorks articles as inspiration: -

Without reposting the entire pair of articles ( which would be a daft idea ), here's a short-cut of what I ended up doing.

For the record, I am using Liberty -

/opt/ibm/WebSphere/Liberty/bin/server version

WebSphere Application Server (1.0.18.cl170320170927-1854) on IBM J9 VM, version pxa6480sr3fp12-20160919_01 (SR3 FP12) (en_GB)

Java 8: -

java -fullversion

java full version JRE 1.8.0 IBM Linux build pxa6480sr3fp12-20160919_01(SR3 FP12)

and Jython 2.7.0: -

So I started by setting up the Jython runtime environment ( this is on the same Red Hat Enterprise Linux box that's hosting Liberty etc. ): -

Create the directory structure

mkdir /opt/ibm/WebSphere/Liberty/jython
cd /opt/ibm/WebSphere/Liberty/jython

Pull Jython 2.7.0

mv remotecontent\?filepath\=org%2Fpython%2Fjython-standalone%2F2.7.0%2Fjython-standalone-2.7.0.jar jython-standalone-2.7.0.jar

Copy the requisite REST Connector classes - both Jython and Java

cp /opt/ibm/WebSphere/Liberty/clients/jython/ .
cp /opt/ibm/WebSphere/Liberty/clients/restConnector.jar .

and then started the Jython environment: -

java -cp jython-standalone-2.7.0.jar:restConnector.jar org.python.util.jython

From there, I established connectivity to my Liberty runtime: -

from restConnector import JMXRESTConnector
JMXRESTConnector.trustStore = '/opt/ibm/WebSphere/Liberty/usr/servers/defaultServer/resources/security/key.jks'
JMXRESTConnector.trustStorePassword = 'passw0rd'
connector = JMXRESTConnector()
connection = connector.connect( '', 9443, 'appcenteradmin', 'admin')

Note that, contrary to the article, this code did not work: -

mconnection = connection.getMBeanServerConnection()

It instead returned: -

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'getMBeanServerConnection'

However, this code DID work: -


and I was able to validate connectivity etc. : -



['MBeanCount', 'PollingMode', 'ServerPollingThread', '__class__', '__copy__', '__deepcopy__', '__delattr__', '__doc__', '__ensure_finalizer__', '__eq__', '__format__', '__getattribute__', '__hash__', '__init__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', '__subclasshook__', '__unicode__', 'addNotificationListener', 'class', 'createMBean', 'defaultDomain', 'domains', 'equals', 'getAttribute', 'getAttributes', 'getClass', 'getDefaultDomain', 'getDomains', 'getMBeanCount', 'getMBeanInfo', 'getObjectInstance', 'hashCode', 'invoke', 'isInstanceOf', 'isRegistered', 'notify', 'notifyAll', 'queryMBeans', 'queryNames', 'removeNotificationListener', 'setAttribute', 'setAttributes', 'toString', 'unregisterMBean', 'wait']


<type ''>

The article then takes one through creating a pair of Python scripts: -

to create an importable library of functions, including: -

connection = connect()

Connecting to the server...
Successfully connected to the server ""

and: -

collect( connection, True,  "WebSphere:type=JvmStats,*")

 MBean details for WebSphere:type=JvmStats

   7 attributes
      UsedMemory [long] = 83109880
      FreeMemory [long] = 41080840
      Heap [long] = 124321792
      UpTime [long] = 22864299
      ProcessCPU [double] = 2.04226135228
      GcCount [long] = 1187
      GcTime [long] = 2457

   0 operations
array(java.lang.Object, [WebSphere:type=JvmStats])

So, in principle, I could use these via Nagios ……

That's the next step ….

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