21 May 2008

Monitoring Mongrels on an F5 BigIP

Almost a year after I raised the issue of problems monitoring Mongrel instances on an F5 BigIP, I still get occasional emails asking whether I got it working and how, etc. So, firing off this blog entry to hopefully provide a more findable solution for folks (the mailman mongrel-users archive seems broken, and clearly people find my initial query on the subject, but not the response with the solution).

So, if you need to monitor Mongrel instances with an F5 BigIP, and are doing so with an HTTP monitor health check, you want to set your Send String to be along the lines of the following:

GET /heartbeat/index HTTP/1.1

The key point here is to have the "\r\n" lines (the "\r" is what I was missing and many folks seem to get tripped up by the proper way to specify the line breaks needed for the HTTP request).

Here's a link to the solution provided by Jason Hoffman of Joyent, on the mongrel-users maiing list.

Note that I haven't worked with F5's since September 2007, so likely can't answer any further questions.


Lori MacVittie said...


Great stuff, and thanks for following up! I see you mention you haven't worked with BIG-IP since 2007 and can't answer other questions, so I thought I'd drop a line and let your readers know that if they have specific questions regarding iRules that the F5 DevCentral community may be a good place to start looking for answers. The DevCentral team is out there every day answering questions, and there's plenty of MVP members in the community who might be able to help as well.


Chris said...

Lori, good point. I agree, F5 DevCentral, as well as F5 support (which you're kind of an idiot to not have if you own F5's), are superb resources as well. I've had great luck with both in the past.