Re: [squid-users] Impressions of 3.2.1

On 7/09/2012 8:49 p.m., Daniel Beschorner wrote:
>> On 7/09/2012 2:54 a.m., Daniel Beschorner wrote:
>>> The shared memory cache is harder to follow in its memory use than in 3.1,
>>> am I right that the "cached" value of the "free" output is somehow related
>>> due to shared mem?
>> Where are you spotting this?
> I'm trying to get the feel of tuning/monitoring the cache_mem parameter in 3.2 SMP.
> Little real mem used, don't know exactly where to look right.
>
> config: linux 64bit, workers 2, no disk cache, 3GB shared mem cache:
>
> Cache information for squid:
> Hits as % of all requests: 5min: 11.3%, 60min: 13.0%
> Hits as % of bytes sent: 5min: 2.1%, 60min: 1.4%
> Memory hits as % of hit requests: 5min: 55.3%, 60min: 52.8%
> Disk hits as % of hit requests: 5min: 25.2%, 60min: 12.7% (?without disk cache?)
> Storage Swap size: 0 KB
> Storage Swap capacity: 0.0% used, 0.0% free
> Storage Mem size: 2997120 KB

3GB cache_mem ^^^

> Storage Mem capacity: 95.3% used, 4.7% free
> Mean Object Size: 0.00 KB
> Requests given to unlinkd: 0
> Resource usage for squid:
> UP Time: 63270.597 seconds
> CPU Time: 2165.255 seconds
> CPU Usage: 3.42%
> CPU Usage, 5 minute avg: 12.62%
> CPU Usage, 60 minute avg: 11.93%
> Process Data Segment Size via sbrk(): 117432 KB
> Maximum Resident Size: 6111728 KB
> Page faults with physical i/o: 0
> Memory usage for squid via mallinfo():
> Total space in arena: 117696 KB
> Ordinary blocks: 105553 KB 3734 blks
> Small blocks: 0 KB 0 blks
> Holding blocks: 2816 KB 8 blks
> Free Small blocks: 0 KB
> Free Ordinary blocks: 12143 KB
> Total in use: 12143 KB 10%
> Total free: 12143 KB 10%
> Total size: 120512 KB
> Memory accounted for:
> Total accounted: 61336 KB 51%

61MB accounted for by MemPools feature in Squid. This is most of the
memory used by Squid, but not everything, and does seem to omit the 3GB
of shared memory cache.

> memPool accounted: 61336 KB 51%
> memPool unaccounted: 59176 KB 49%

59MB in that omitted group. Counted by mallinfo() but not by Squid MemPools.

Total of about 100MB other memory. Its not clear from here whether that
is across al processes, or for just one. But ...

> memPoolAlloc calls: 495209534
> memPoolFree calls: 497771963
> Internal Data Structures:
> 5509 StoreEntries
> 5509 StoreEntries with MemObjects
> 93660 Hot Object Cache Items
> 0 on-disk objects
>
>
> free output: (only 300M "normal" mem used? but also only 1,4GB in "cached", if shared mem is accounted there?)
>
> total used free shared buffers cached
> Mem: 3926544 1841484 2085060 0 103584 1434028
> -/+ buffers/cache: 303872 3622672
> Swap: 2095100 0 2095100
>
>
> top output:
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> 8118 nobody 20 0 3167m 724m 676m S 7 18.9 18:02.57 squid
> 8119 nobody 20 0 3189m 783m 713m S 5 20.4 18:44.31 squid

3.2GB of virtual memory used by each process. That would be 3GB memory
cache and ~100MB of other memory use by each Squid process.

Amos
Received on Sat Sep 08 2012 - 00:07:57 MDT