Trac taking a hammering

At work we have one VM which hosts all our project management software like Git, SVN, Trac and Bugzilla. However, recently it has been taking a hammering and essentially crashing. The issue was it was running out of RAM, and swapping like crazy. A little investigation into the situation uncovered that there were some Trac 0.10 CGI processes which were using >500MB of memory.

Using the ps ewww -p <pid> command to look at the enviornment variables of the processes we determined that each of them was serving the same kind of request, SVN changesets. And essentially all of them were being hit by spiders.

Essentially the issue was that the spiders were managing to create a large number of overlapping changeset requests, which were chewing up all the RAM on the VM. Increasing the amount of RAM wouldn’t only offset the problem. So, we now just block the spiders from the changeset areas of our tracs (robots.txt):

User-agent: *
Request-rate: 1/5
Disallow: /projects/data-activities/changeset
...

In the weeks since then we’ve had no issues. Besides, who wants their gaffs showing up on google

Interestingly we’ve not seen the same thing happen with Trac 0.11, so perhaps the issue is resolved now.

Zope3 Component Architecture (CA) style Adapters for Java

After programming for Zope3/Plone for the past year I’ve come to really
admire the flexibility and elegance that their implementation of the
adapter pattern gives us.
And, after Martin Aspeli put the call out almost a year ago, and it has not yet been answered, I thought it was time to give it a go.
How hard could it be.

So, what I’ve developed is a very simple, no dependency, maven available library which should greatly improve the flexibility of your code.

The project page is here
and the repository is at Git Hub.