Frozen apt-get can lead to very high memory consumption
OS: Ubuntu 8.04 LTS
ISPConfig periodically executes an
apt-get update command to update the package database before listing packages need to be upgraded. But now the Ubuntu servers seem to be hammered by high load or something else (at least the servers for the security updates), which causes apt-get update to hang. It causes dozens of stuck in php processes executing the server backend. Each of them consumes memory and this effect eventually leads to high memory consumption and swapping. I also observed delayed processing of changes by slave servers.
I use apt-proxy to "cache" the repository accesses, but it worked with the same configuration before. I tried to clear the caches of both apt-proxy and apt, but it did not help.
I think ISPConfig should not execute
apt-get update at all and let the system administrator to schedule that task separately. ISPConfig itself could add that as a daily cron script separately. It'd allow for limiting the effect of such repository failures.