Squid has “sum hash mismatch” errors with bz2 files

Question

Ive been experiencing problems with my squid3 recently, i am using 10.04.3 LTS. Configured squid as always have been configuring since 8.04.04, but its not working as it should be.

Ive been having issues with bz2 files, in my LAN when i try to do an apt-get update, it just says some indexex could not be downloaded cause of a sum hash mismatch.

If you check squid log, for that kind of file it says

TCP_REFRESH_UNMODIFIED/206 

Google around i read thats ssquid cache keeppin the files more than usual, so i add this hoping to solve the problem:

refresh_pattern -i \.bz2$       0       0%      60      override-lastmod refresh-ims override-expire

I dont know if thats well written or not, but it doesnt have solve the problem, and know squid log shows,

TCP_REFRESH_UNMODIFIED/304

but the same behaviour of the hash sum mismatch, please if someone could throw a ligth in here. The only fix to this problem so far is deleting all cache and recreate it every morning, which is far from a solution.

Any help will be greatly apreciate it.

regards.

Answer 1

I was recently reading an IRC log of a conversation between one of squid's authors and one of the Ubuntu archive admins and I believe there are actually issues with the way the archive sets the 'Expires:' header which sometimes causes this problem. It should not ever be a problem with the released version of Ubuntu, so it will only be a problem with -updates/-security and with the current dev release. Basically what happens is squid gets the Packages.bz2 from one mirror, and then later it is updated but your cache doesn't get it, leading to files missing or what appears to be a corrupt Packages.bz2.