More than you ever wanted to know about your Liberty configuration – overview

It all started with wanting to look at the MQ configuration within MQWEB and z/OS Connect. I could not find a way of displaying the Liberty configuration information. I could look at the *.xml files, but this did not give me the information which is not in the configuration files. I thought about writing a Liberty feature which printed out the configuration, but then I stumbled across OSGI and the ability to query configuration information from outside of Liberty.

What is OSGI ?

The OSGi specification describes a modular system and a service platform for the Java programming language that implements a complete and dynamic component model, something that does not exist in standalone Java/VM environments. Applications or components, coming in the form of bundles for deployment, can be remotely installed, started, stopped, updated, and uninstalled without requiring a reboot; management of Java packages/classes is specified in great detail. Application life cycle management is implemented via APIs that allow for remote downloading of management policies. The service registry allows bundles to detect the addition of new services, or the removal of services, and adapt accordingly.

Wikipedia

OSGI uses the term “bundle”. It looks like a bundle is a jar file, and the facilities within it. Listing one bundle had com.ibm.ws.ssl_1.3.41.cl200620200528-0414 [72] in it.

  • com.ibm.ws.ssl_1.3.41 is a jar file com.ibm.ws.ssl_1.3.41.jar
  • many files had cl200620200528-0414
  • [72] this was for bundle 72.

How does it work?

Each program package(jar file) contains a manifest.mf file. For example

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: MyService bundle
Bundle-SymbolicName: com.sample.myservice
Bundle-Version: 1.0.0
Bundle-Activator: com.sample.myservice.Activator
Import-Package:  org.apache.commons.logging;version="1.0.4"
Export-Package:  com.sample.myservice.api;version="1.0.0"

This gives information on

  • Information about your package (including its version number).
  • The entry point for the bundle.
  • What services it provide to other packages (com.sample.myservice.api).
  • What services it needs from other packages in order for it to work (com.sample.myservice.api).

OSGI sorts out all of these dependencies, provides access to the configuration in the *.xml files and additional configuration data hidden within the packages.

How can I use it to display configuration?

This is not very well documented. I think it is dangerous, as the osgi port allows unauthenticated access to start and stop services. I have not been able to restrict it to authorised users, or control what users have access to.

I found the following….

You need to specify in your Liberty *.xml files

<featureManager> 
<feature>osgiConsole-1.0</feature>
</featureManager>

and put

osgi.console=ip:port 

in the bootstrap.properties file. For example osgi.console=10.1.3.10:5471 . I found a reference to osgi.console.ssh=ip:port, but this port was not opened during liberty startup.

If you specify osgi.console=5471, this uses the localhost 127.0.0.1, so you can only access it from the local machine. For example TSO TELNET 127.0.0.1 5471. Telnet from TSO is not very usable – it is better to use a telnet session from off z/OS, for example Linux.

From Linux I used:

telnet 10.1.3.10 5471 |tee -i osgi.log

This allowed me to issue interactive commands, and have the output written to the osgi.log file.

There are a variety of commands to display, start stop etc.

The list bundle command lb gave over 200 entries like

177|Active | 12|com.ibm.ws.messaging.jmsspec.common... 
178|Active | 12|com.ibm.websphere.javaee.jms.2.0 ... 
179|Active | 12|WMQ Resource Adapter ... 

The command bundle 179 gave information about the WMQ Resource Adapter above.

I used the bundles command to list all information about all bundles. I then used some python script to process the log file and write information about each bundle to its own file. From the jca file I could see com.ibm.ws.jca.service.ConnectionFactoryService has properties

jndiName=jms/cf1
properties.0.CCSID=819
properties.0.cleanupLevel=SAFE
properties.0.cloneSupport=DISABLED
properties.0.config.referenceType=com.ibm.ws.jca.properties.wmqJms.jmsConnectionFactory
properties.0.connectionfactory-interface=javax.jms.ConnectionFactory
properties.0.failIfQuiesce=true
properties.0.headerCompression=NONE
properties.0.managedconnectionfactory-class=com.ibm.mq.connector.outbound.ManagedConnectionFactoryImpl
properties.0.messageCompression=NONE
properties.0.messageSelection=CLIENT
properties.0.port=1414
properties.0.providerVersion=unspecified
properties.0.pubAckInterval=25
properties.0.queueManager=CSQ9
properties.0.rescanInterval=5000
properties.0.resourceAdapterConfig.id=wmqJms
properties.0.shareConvAllowed=true
properties.0.sparseSubscriptions=false
properties.0.sslResetCount=0
properties.0.statusRefreshInterval=60000
properties.0.subscriptionStore=BROKER
properties.0.targetClientMatching=true
properties.0.transportType=BINDINGS
properties.0.wildcardFormat=TOPIC

and I could see the key properties for the queue manager connection.

For my MQ queue I could see

jndiName=jms/stockRequestQueue
properties.0.CCSID=1208
properties.0.adminobject-class=com.ibm.mq.connector.outbound.MQQueueProxy
properties.0.adminobject-interface=javax.jms.Queue
properties.0.arbitraryProperties=
properties.0.baseQueueManagerName=
properties.0.baseQueueName=STOCK_REQUEST
properties.0.config.referenceType=com.ibm.ws.jca.properties.wmqJms.jmsQueue
properties.0.encoding=NATIVE
properties.0.expiry=APP
properties.0.failIfQuiesce=true
properties.0.persistence=APP
properties.0.priority=APP
properties.0.putAsyncAllowed=DESTINATION
properties.0.readAheadAllowed=DESTINATION
properties.0.readAheadClosePolicy=ALL
properties.0.receiveConversion=CLIENT_MSG
properties.0.resourceAdapterConfig.id=wmqJms
properties.0.targetClient=MQ

and finally I found the connection pool information I was looking for:

connectionTimeout=30
id=ConMgr1
maxIdleTime=1800
maxPoolSize=5
purgePolicy=EntirePool
reapTime=180

Phew – what a lot of work to get this information.

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