To make better use of the Drupal.org servers we've set up PHP to utilize an opcode cache (APC). After a few tweaks, the cache is helping out by almost halving load and CPU usage. Drupal.org traffic has continued to grow over last year, nearly doubling. Additionally with sites such as themes.drupal.org, api.drupal.org, and groups.drupal.org, the two web nodes weren't too far from hitting their limits. APC ought to allow drupal.org and friends to run happily, longer, on the same hardware.

Attached is a graph showing the CPU usage before and after (about since 16:30) on drupal1.

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