Over the past couple of months the machine which hosts the Debian Administration website has been struggling with two distinct problems:
- The dreaded scheduler bug/issue
The machine would frequently hang with the messages of the form:
Task xxx blocked for more than 120 seconds
This would usually require the application of raised elephants to recover from.
- OOM-issues
The system would exhaust the generous 2Gb of memory it possessed, and start killing random tasks until the memory usage fell - at which point the server itself stopped functioning in a useful manner.
Hopefully these problems are now over:
- Bytemark have generously increased the memory installed upon this (donated) machine from 2Gb to 4Gb.
- I've cleaned up some of the site code and switched to using a combination of nginx & apache 2 to serve the site. (I've documented this upon the site itself : Speeding up dynamic websites via an nginx proxy.)
The combination of these two changes should resolve the memory issues, and I've installed a home-made 2.6.31.4 kernel which appears to have corrected the task-blocking scheduler issue.
ObTitle: Bridget Jones: The Edge of Reason
Tags: apache2, bytemark, debian-administration, nginx, performance 2 comments