Is it possible to set specific times to run cache removal (lru)?
Reason being, at random times the squid process cpu is a high 40% and greater. Sometimes the squid process uses 99% cpu, but this is more rare.
Normally the squid process uses 10% or less of cpu.
Is it possible that the cache is causing the high cpu and if so, could the users use cache without lru running? And then later in evening/night activate cache removal lru?
Should I switch the cache replacement policy from "lru" to GDSF or LFUDA ?
The high cpu has occured for quite some time - with no difference on which squid version or system machines. I've always checked cache log, but it has no errors. Just a lot of "sslReadServer: FD 149: read failure: (104) Connection reset by peer". The random high cpu for squid process is occurring on our main parent squid cache system. We've got 20 remote systems running squid caches that then proxy thru to our main parent system.
I just placed squid in debug mode (while the squid process was using a lot of cpu). Lots of log info to look at.
Squid Cache: Version 2.5.STABLE2-20030402
configure options: --prefix=/s1/squid2.5.2 --enable-delay-pools --enable-snmp --enable-basic-auth-helpers=LDAP --enable-basic-auth-helpers=NCSA --enable-storeio=aufs
System OS is RedHat 7.1.2 with kernel 2.4.9-31smp. cpu is AMD Athlon with cpu MHz 1533.431. Mem: 1027936K av, 1022528K used, 5408K free.
system has raid.
Any suggestions or ideas would be great. I've never been able to figure out why squid process sometimes uses a lot of cpu. Listed is the Store Dir Stats and cache mgr info.
Thank you !
Store Directory Statistics: Store Entries : 428328 Maximum Swap Size : 5242880 KB Current Store Swap Size: 4718588 KB Current Capacity : 90% used, 10% free
Store Directory #0 (aufs): /d1/squid_cache FS Block Size 4096 Bytes First level subdirectories: 16 Second level subdirectories: 256 Maximum Size: 5242880 KB Current Size: 4718588 KB Percent Used: 90.00% Filemap bits in use: 428190 of 524288 (82%) Filesystem Space in use: 11910012/17488652 KB (68%) Filesystem Inodes in use: 453971/2223872 (20%) Flags: SELECTED Removal policy: lru LRU reference age: 4.91 days
Squid Object Cache: Version 2.5.STABLE2-20030402
Start Time: Mon, 08 Sep 2003 17:14:09 GMT
Current Time: Mon, 20 Oct 2003 17:44:54 GMT
Connection information for squid:
Number of clients accessing cache: 440
Number of HTTP requests received: 25319108
Number of ICP messages received: 18278
Number of ICP messages sent: 18278
Number of queued ICP replies: 0
Request failure ratio: 0.00
Average HTTP requests per minute since start: 418.4
Average ICP messages per minute since start: 0.6
Select loop called: 366800967 times, 9.898 ms avg
Cache information for squid:
Request Hit Ratios: 5min: 32.9%, 60min: 32.0%
Byte Hit Ratios: 5min: 6.8%, 60min: 7.2%
Request Memory Hit Ratios: 5min: 2.0%, 60min: 1.0%
Request Disk Hit Ratios: 5min: 15.1%, 60min: 19.1%
Storage Swap size: 4718588 KB
Storage Mem size: 8152 KB
Mean Object Size: 11.08 KB
Requests given to unlinkd: 0
Median Service Times (seconds) 5 min 60 min:
HTTP Requests (All): 0.16775 0.15888
Cache Misses: 0.20843 0.22004
Cache Hits: 0.01387 0.01387
Near Hits: 0.12783 0.14252
Not-Modified Replies: 0.00865 0.00865
DNS Lookups: 0.00779 0.00669
ICP Queries: 0.00000 0.00000
Resource usage for squid:
UP Time: 3630645.350 seconds
CPU Time: 200231.640 seconds
CPU Usage: 5.52%
CPU Usage, 5 minute avg: 14.85%
CPU Usage, 60 minute avg: 15.72%
Process Data Segment Size via sbrk(): 90135 KB
Maximum Resident Size: 0 KB
Page faults with physical i/o: 9365
Memory usage for squid via mallinfo():
Total space in arena: 90135 KB
Ordinary blocks: 67305 KB 2854 blks
Small blocks: 0 KB 0 blks
Holding blocks: 324 KB 2 blks
Free Small blocks: 0 KB
Free Ordinary blocks: 22829 KB
Total in use: 67629 KB 75%
Total free: 22829 KB 25%
Total size: 90459 KB
Memory accounted for:
Total accounted: 53066 KB
memPoolAlloc calls: 3782602115
memPoolFree calls: 3781280094
File descriptor usage for squid:
Maximum number of file descriptors: 1024
Largest file desc currently in use: 409
Number of file desc currently in use: 335
Files queued for open: 0
Available number of file descriptors: 689
Reserved number of file descriptors: 100
Store Disk files open: 0
Internal Data Structures:
426041 StoreEntries
1770 StoreEntries with MemObjects
1759 Hot Object Cache Items
425934 on-disk objects