[squid-users] Memory Leak Squid 3.4.9 on FreeBSD 10.0 x64

Doug Sampson dougs at dawnsign.com
Wed Dec 10 15:22:37 UTC 2014


> Nothing particularly stands out as leaking. Although the cache memory
> pages (mem_node) in-use size is suspiciously close to half what you
> say the OS is reporting.
> 
> That makes me suspect that your OS is rounding up its allocations to
> 8KB of memory for each node. If that is the case the simplest
> workaround is to reduce cache_mem size down to below the point where
> the box will swap.

Okay, I'll keep dropping the cache_mem down until the system stops swapping. Hopefully not too much.

Would it make sense to add additional memory in order to reduce the possibility of swapping? Say, 1GB more?

> If you are game for it I have been wondering if we need to enable
> chunking for 64-bit systems. To test that run squid with environment
> variable MEMPOOLS=1.
>  Memory should then be allocated in larger blocks, but utilized much
> more compactly within those blocks for an overall saving on objects
> like mem_node. It is currently a rarely used feature though, so I'm
> not sure if there are any issues hiding.
> 

I'm reluctant to do this on a production server. Interfacing with our customers via social media et al is an important part of our business.

Nevertheless, I looked into how the MEMPOOLS parameter could be implemented in a FreeBSD machine. I couldn't find a post that clearly indicates how to implement it. The nearest reference I could find was that FreeBSD implements UMA which apparently with my limited knowledge is a parallel memory implementation of MEMPOOLS. Correct me if I'm terribly mistaken.

~Doug


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