{"id":41939,"date":"2015-07-26T15:00:31","date_gmt":"2015-07-26T12:00:31","guid":{"rendered":"http:\/\/www.javacodegeeks.com\/?p=41939"},"modified":"2015-07-21T12:05:13","modified_gmt":"2015-07-21T09:05:13","slug":"monitoring-devops-style-with-wildfly-9-and-jolokia","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/2015\/07\/monitoring-devops-style-with-wildfly-9-and-jolokia.html","title":{"rendered":"Monitoring DevOps Style With WildFly 9 And Jolokia"},"content":{"rendered":"

DevOps is among the hottest topic these days. And the wide range of topics around it makes it hard to actually find a complete description or something that covers everything on a decent granularity. One thing is for sure: One of the most important parts is to deliver the correct metrics and and information for monitoring of the application.
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Java EE and JMX<\/h2>\n

\"visual-vm\"<\/a><\/p>\n

The standard way of monitoring Java EE servers is JMX. This is possible with tools like JConsole, VisualVM or the Oracle Mission-Control Suite. There are a bunch of advantages to this approach and most of the operation teams actually used this a lot in the past. But it doesn’t exactly works the DevOps-way. It is a separate tooling and the DevOps-teams don’t have a good way to actually script this without having all the tooling and operational systems (Nagios, etc.) installed. Today it feels a lot more natural and is easier to use to have http endpoints which expose configuration and runtime information.<\/p>\n

Jolokia – JMX To HTTP With JSON<\/h2>\n

A very convenient way to do this for JMX is to use Jolokia<\/a>.\u00a0Jolokia is a JMX-HTTP bridge giving an alternative to JSR-160 connectors. It is an agent based approach with support for many platforms. In addition to basic JMX operations it enhances JMX remoting with unique features like bulk requests and fine grained security policies. It comes bundled with a lot of JBoss projects lately (e.g. WIldFly-Camel subsystem) and can be easily used in your own applications.<\/p>\n

A Simple Java EE 7 App Equipped With Jolokia<\/h2>\n

Just create a simple Java EE 7 project (maybe with Adam Bien’s maven artifact<\/a>) and add one dependency to it:<\/p>\n

<dependency>\r\n \u00a0 \u00a0 <groupId>org.jolokia<\/groupId>\r\n \u00a0 \u00a0 <artifactId>jolokia-core<\/artifactId>\r\n \u00a0 \u00a0 <version>1.3.1<\/version>\r\n <\/dependency><\/pre>\n
The next step is to configure the Jolokia AgentServlet in your web.xml and map it to a pattern which suits your needs:
 
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\u00a0 <servlet>\r\n\u00a0 \u00a0 \u00a0 \u00a0 <servlet-name>jolokia-agent<\/servlet-name>\r\n\u00a0 \u00a0 \u00a0 \u00a0 <servlet-class>org.jolokia.http.AgentServlet<\/servlet-class>\r\n\u00a0 \u00a0 \u00a0 \u00a0 <load-on-startup>1<\/load-on-startup>\r\n\u00a0 \u00a0 <\/servlet>\r\n\r\n\u00a0 \u00a0 <servlet-mapping>\r\n\u00a0 \u00a0 \u00a0 \u00a0 <servlet-name>jolokia-agent<\/servlet-name>\r\n\u00a0 \u00a0 \u00a0 \u00a0 <url-pattern>\/metrics\/*<\/url-pattern>\r\n\u00a0 \u00a0 <\/servlet-mapping><\/pre>\n
Build your application as usual and access the relevant metrics as you need them. The complete . Jolokia reference explains the different operations and types<\/a>.<\/p>\n
Deploy Your Application To WildFly 9<\/h2>\n
Download and unzip WildFly 9<\/a> to a folder of your choice. Startup with bin\/standalone.xml.<\/p>\n
Example Metrics<\/h2>\n
While you can access every JMX MBean, that is defined in the server, here is a list of metrics, that might help you out of the box.<\/p>\n
Heap memory usage:<\/p>\n