Description of problem:
Response Time (CallTime) metrics for an IIS VHost are not being collected and the following message is logged in the agent:

DEBUG [ResourceContainer.invoker.daemon-2] (org.rhq.plugins.iis.IISResponseTimeDelegate)- No log files exist yet


This failure is due to the plug-in looking for the wrong file name prefix. It appears that in IIS 7+ the default log file name begins with "u_ex" however, in IIS 6 (and the existing plug-in) "ex" was the prefix.

Version-Release number of selected component (if applicable):
4.4.0.JON311GA

How reproducible:
Always

Additional info:
From the support engineer who did some preliminary investigating:

After performing some tests locally, I have identified that the root cause should be related to the logging file name. As described in this page [2], "By Default IIS 7 log file format is stored using the u_ex prefix rather than ex prefix as seen in IIS 6." and there is a validation to check the logging file name, as follows:

**CLASS: IISResponseTimeDelegate

 -> This is a snippet of the class that contains the method responsible for validating the file name:

        private class IISResponseTimeLogFileFilter implements FileFilter {
            public boolean accept(File f) {
                String fileName = f.getName().toLowerCase();
                return fileName.startsWith("ex") && fileName.endsWith(".log");
            }
        }