Support ClassLoadingMXBean

[DavidWhitlock]

So, I'm going to start a series of issues on the standard JDK MBeans that we want to make sure can be extracted and loaded. I'm also putting together the skeleton of fitnesse tests so that we can have automated tests for these MBeans.

The first one is "java.lang:type=ClassLoading" (http://docs.oracle.com/javase/6/docs/api/java/lang/management/ClassLoadingMXBean.html)) which has a boolean attribute, an int attribute, and two long attributes.

I would expect that the following XML can be used to extract the Class Loading MBean

<Settings>
  <pollingRate>2</pollingRate>
  <folderLocation>extractClassLoadingMXBeans</folderLocation>
  <url>service:jmx:rmi:///jndi/rmi://:8888/jmxrmi</url>
  <BeanList>
    <Bean>
      <name>java.lang:type=ClassLoading</name>
      <alias>ClassLoading</alias>
      <AttributeList>
        <Attribute>
          <dataType>BOOLEAN</dataType>
          <name>Verbose</name>
        </Attribute>
        <Attribute>
          <dataType>INT</dataType>
          <name>LoadedClassCount</name>
        </Attribute>
        <Attribute>
          <dataType>LONG</dataType>
          <name>UnloadedClassCount</name>
        </Attribute>
        <Attribute>
          <dataType>LONG</dataType>
          <name>TotalLoadedClassCount</name>
        </Attribute>
      </AttributeList>
      <enable>true</enable>
    </Bean>
  </BeanList>
</Settings>

At the moment, this XML blows up in the Extractor with the following exception.

Caused by: java.lang.IllegalArgumentException: No enum const class org.jmxdatamart.common.DataType.BOOLEAN
    at java.lang.Enum.valueOf(Enum.java:196)
    at com.thoughtworks.xstream.converters.enums.EnumConverter.unmarshal(EnumConverter.java:47)
    at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)

Which I believe is expected given other open issues.

[ankel]

Can you try remove all and re-run the above settings?

[ankel]

Scratch that. The error was because ms sql doesn't support boolean type, thus neither is extractor. How do you propose we should do to support Boolean?

[DavidWhitlock]

I don't know how to best represent boolean values in MS SQL Server. Google has a couple of ideas, though:

• http://stackoverflow.com/questions/1777257/how-do-you-create-a-yes-no-boolean-field-in-sql-server
• http://social.msdn.microsoft.com/Forums/en-US/sqlexpress/thread/9b167189-2ad2-4656-b8ca-00aa2ae4262e/

[ankel]

I think it should be best to ask your Datamart / MS SQL team since we don't want to introduce some new / different way into Tripwire's ecosystem, unless Tripwire is using some super-secret way, then we'll fall back to other ways.

As far as the actual change, let's say if we decided to use bit (as both link suggest) then it would be as simple as adding an extra case for bit type in loader, and a conversion true -> 1, false -> 0 in extractor.

[DavidWhitlock]

I'll ask the Data Mart guys what they do with boolean columns, but I'm pretty sure they'd use bit also.