I have some Dell 1950 servers dedicated to squid in my production
environment. Each with 16GB RAM and 300G disk
As the website traffic grows, the load of squid becomes high at high
traffic time. Average load is higher than 10.
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz
avgqu-sz await svctm %util
sda 0.00 0.01 0.06 0.13 1.23 1.45 28.87
0.00 4.13 2.19 0.04
sda1 0.00 0.01 0.06 0.11 1.23 1.45 31.59
0.00 4.52 2.40 0.04
sdb 0.07 0.07 0.01 0.01 0.33 0.32 59.88
0.00 19.75 15.74 0.03
sdc 0.00 2.08 9.13 104.44 81.30 1066.74
20.22 0.50 11.95 1.73 19.63
avg-cpu: %user %nice %system %iowait %steal %idle
3.50 0.00 3.75 24.34 0.00 68.41
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz
avgqu-sz await svctm %util
sda 0.00 0.00 0.50 0.00 2.00 0.00 8.00
0.04 70.00 70.00 3.50
sda1 0.00 0.00 0.50 0.00 2.00 0.00 8.00
0.04 70.00 70.00 3.50
sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0.00 0.00 0.00 0.00
sdc 0.00 0.00 21.50 186.00 204.00 3106.25
31.91 17.76 100.55 2.63 54.65
Here is the squidclient mgr:info output
Squid Object Cache: Version 3.1.12
Start Time: Sun, 14 Aug 2011 19:39:15 GMT
Current Time: Thu, 18 Aug 2011 04:41:20 GMT
Connection information for squid:
Number of clients accessing cache: 77651
Number of HTTP requests received: 40449309
Number of ICP messages received: 0
Number of ICP messages sent: 0
Number of queued ICP replies: 0
Number of HTCP messages received: 0
Number of HTCP messages sent: 0
Request failure ratio: 0.00
Average HTTP requests per minute since start: 8319.3
Average ICP messages per minute since start: 0.0
Select loop called: 476454933 times, 0.612 ms avg
Cache information for squid:
Hits as % of all requests: 5min: 30.7%, 60min: 32.1%
Hits as % of bytes sent: 5min: 40.5%, 60min: 43.2%
Memory hits as % of hit requests: 5min: 88.3%, 60min: 88.8%
Disk hits as % of hit requests: 5min: 1.6%, 60min: 1.9%
Storage Swap size: 120792244 KB
Storage Swap capacity: 90.0% used, 10.0% free
Storage Mem size: 5191632 KB
Storage Mem capacity: 100.0% used, 0.0% free
Mean Object Size: 20.61 KB
Requests given to unlinkd: 0
Median Service Times (seconds) 5 min 60 min:
HTTP Requests (All): 0.00865 0.00865
Cache Misses: 0.01035 0.01035
Cache Hits: 0.00000 0.00000
Near Hits: 0.00091 0.00091
Not-Modified Replies: 0.00000 0.00000
DNS Lookups: 0.00000 0.00000
ICP Queries: 0.00000 0.00000
Resource usage for squid:
UP Time: 291725.519 seconds
CPU Time: 37204.391 seconds
CPU Usage: 12.75%
CPU Usage, 5 minute avg: 19.42%
CPU Usage, 60 minute avg: 18.20%
Process Data Segment Size via sbrk(): 1012440 KB
Maximum Resident Size: 28552368 KB
Page faults with physical i/o: 2957
Memory usage for squid via mallinfo():
Total space in arena: -1265560 KB
Ordinary blocks: -1308538 KB 264611 blks
Small blocks: 0 KB 0 blks
Holding blocks: 20708 KB 9 blks
Free Small blocks: 0 KB
Free Ordinary blocks: 42978 KB
Total in use: -1287830 KB 103%
Total free: 42978 KB -3%
Total size: -1244852 KB
Memory accounted for:
Total accounted: -1781767 KB 143%
memPool accounted: 6606841 KB -531%
memPool unaccounted: -7851693 KB 0%
memPoolAlloc calls: 10008474163
memPoolFree calls: 10065124847
File descriptor usage for squid:
Maximum number of file descriptors: 20480
Largest file desc currently in use: 4828
Number of file desc currently in use: 4703
Files queued for open: 178
Available number of file descriptors: 15599
Reserved number of file descriptors: 100
Store Disk files open: 22
Internal Data Structures:
5860834 StoreEntries
256880 StoreEntries with MemObjects
256646 Hot Object Cache Items
5860661 on-disk objects
related parameters
cache_mem 5120 MB
maximum_object_size 51200 KB
maximum_object_size_in_memory 1024 KB
log_icp_queries off
cache_swap_low 90
cache_swap_high 95
hosts_file /etc/squid/hosts
cache_dir aufs /export/squid/cache 131072 32 256
Is there any idea I can tune my squid performance?
