[squid-users] Memory leak in squid 2.5STABLE13?

I have four servers running 2.5STABLE13, each handling ~100 requests/second.
They're all running on RedHat Linux ES 2.1. Each of the four servers leaks
about 100 MB a week. It's been that way for years. I restart squid once a
month so I don't run out of memory.

Here's some cachemgr output:
Squid Object Cache: Version 2.5.STABLE13
Start Time: Sat, 15 Apr 2006 21:43:47 GMT
Current Time: Mon, 24 Apr 2006 19:22:37 GMT
Connection information for squid:
        Number of clients accessing cache: 0
        Number of HTTP requests received: 12318603
        Number of ICP messages received: 3718919
        Number of ICP messages sent: 3719279
        Number of queued ICP replies: 0
        Request failure ratio: 0.00
        Average HTTP requests per minute since start: 961.0
        Average ICP messages per minute since start: 580.3
        Select loop called: 102978835 times, 7.469 ms avg
Cache information for squid:
        Request Hit Ratios: 5min: 76.4%, 60min: 66.9%
        Byte Hit Ratios: 5min: 19.1%, 60min: 9.3%
        Request Memory Hit Ratios: 5min: 4.6%, 60min: 6.4%
        Request Disk Hit Ratios: 5min: 6.3%, 60min: 9.9%
        Storage Swap size: 31866372 KB
        Storage Mem size: 98444 KB
        Mean Object Size: 14.16 KB
        Requests given to unlinkd: 0
Median Service Times (seconds) 5 min 60 min:
        HTTP Requests (All): 0.00562 0.00767
        Cache Misses: 0.12783 0.13498
        Cache Hits: 0.00463 0.00463
        Near Hits: 0.06640 0.07409
        Not-Modified Replies: 0.00379 0.00463
        DNS Lookups: 0.03223 0.03374
        ICP Queries: 0.00137 0.00185
Resource usage for squid:
        UP Time: 769130.108 seconds
        CPU Time: 49356.840 seconds
        CPU Usage: 6.42%
        CPU Usage, 5 minute avg: 21.48%
        CPU Usage, 60 minute avg: 26.74%
        Process Data Segment Size via sbrk(): 492179 KB
        Maximum Resident Size: 0 KB
        Page faults with physical i/o: 2439
Memory usage for squid via mallinfo():
        Total space in arena: 492179 KB
        Ordinary blocks: 454101 KB 344150 blks
        Small blocks: 0 KB 0 blks
        Holding blocks: 19968 KB 12 blks
        Free Small blocks: 0 KB
        Free Ordinary blocks: 38077 KB
        Total in use: 474069 KB 93%
        Total free: 38077 KB 7%
        Total size: 512147 KB
Memory accounted for:
        Total accounted: 258504 KB
        memPoolAlloc calls: 1436813623
        memPoolFree calls: 1431954945
File descriptor usage for squid:
        Maximum number of file descriptors: 4096
        Largest file desc currently in use: 389
        Number of file desc currently in use: 226
        Files queued for open: 0
        Available number of file descriptors: 3870
        Reserved number of file descriptors: 100
        Store Disk files open: 1
Internal Data Structures:
        2263720 StoreEntries
         18309 StoreEntries with MemObjects
         18288 Hot Object Cache Items
        2250084 on-disk objects

Notice that the memory usage "Total in Use:" is 474 MB, while the
Memory accounted for is only 258 MB. I've tried configuring with
--enable-dlmalloc and that didn't have any affect on the memory leak.
I've also tried replacing the version of dlmalloc (2.6.4) that's
shipped with squid with a newer version (2.7.2), but that didn't
have any affect either.

Does anyone have an idea of what I should try next?

Mike Mitchell
SAS Institute Inc.
Mike.Mitchell@sas.com
(919) 531-6793
Received on Mon Apr 24 2006 - 13:47:32 MDT