JMXetricAgentIT fails with NumberFormatException about jmxetric HOT 3 CLOSED

It seems like this line

String sampleDMax = selectParameterFromNode(sample, "dmax", "0");

is causing trouble, its return value should be "0", since dmax isn't in the sample jmxetric_text.xml file. For somehow it returns "".

from jmxetric.

Think I've found the problem. In jmxetric_test.xml, we have the following doctype

   <!ELEMENT sample (mbean)*>
      <!ATTLIST sample delay CDATA #REQUIRED>
      <!ATTLIST sample dmax CDATA "" >

This meant that dmax is always going to be present, with a default value of "". Hence the method selectParameterFromNode in XMLConfigurationService:

            Node node = ganglia.getAttributes().getNamedItem(attributeName);
            if ( node != null ) {
                String value = node.getNodeValue();
                if ( value != null )
                    ret = value ;
            }

would return "", as node is never null for dmax, since a default value was given in the XML doctype.

2 ways to fix this:

1. remove that attribute from sample
2. give it a default string of "0", because that's what the code does anyway

Referencing the initialdelay attribute in etc/jmxetric.xml, it seems that 2. is a better way:

   <!ELEMENT sample (mbean)*>
      <!ATTLIST sample delay CDATA #REQUIRED>
      <!ATTLIST sample initialdelay CDATA "0">
      <!ATTLIST sample dmax CDATA "" >

and note that dmax has an empty default string here as well.

@dpocock which way would be suitable?

from jmxetric.

I would suggest two things:

• fix the default in the sample, change it to "0"
• some people may have already copied that sample and may not notice the fix. Therefore, I think that in the code it should check if sampleDMax.equals("") and if so replace it with 0

from jmxetric.