Re[2]: [squid-users] Frequent cache rebuilding

>> For 6 days uptime:
>> # vmstat
>> procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
>> r b swpd free buff cache si so bi bo in cs us sy id wa st
>> 2 0 92 104052 235704 2309956 0 0 3 43 24 33 10 16 73 1 0
>>
>> As you can see system has spent only 1% of CPU time in I/O wait.
>> (cpu-wa column).
>>

> This also shows the CPU has been 73% idle. If I'm not mistaken, you
> stated that you had a two CPU (core) system, which would still leave one
> of the cores at 50% idle. Running "vmstat 2" while you are experiencing
> load will give more insight.

It's because at night time squid doesn't use so much CPU (around 10%
of 1 core).

Here is the output from "vmstat 2":
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
 r b swpd free buff cache si so bi bo in cs us sy id wa st
 2 0 92 704676 274360 2354952 0 0 3 34 7 20 10 16 74 0 0
 1 0 92 703800 274364 2355312 0 0 0 0 1722 123 22 35 42 0 0
 1 0 92 703552 274392 2355476 0 0 2 378 1732 162 20 36 43 0 0
 1 0 92 703180 274396 2355912 0 0 0 45 1670 132 20 35 45 0 0
 2 0 92 702436 274412 2356408 0 0 6 482 1758 124 20 37 42 1 0
 1 0 92 701576 274432 2356792 0 0 4 20 1687 122 21 43 35 0 0
 1 0 92 701204 274440 2357016 0 0 4 8 1645 130 18 34 47 0 0
 1 0 92 700584 274452 2357160 0 0 2 474 1696 150 21 37 40 1 0
 1 0 92 700088 274484 2357460 0 0 16 8 1656 166 21 34 45 0 0
 1 0 92 699220 274516 2357508 0 0 10 388 1722 146 22 36 41 2 0
 1 0 92 698724 274532 2357660 0 0 8 26 1670 129 22 41 37 0 0
 1 0 92 698352 274536 2357992 0 0 2 0 1743 122 20 36 44 0 0
 2 0 92 697484 274556 2358036 0 0 4 304 1743 141 22 37 41 1 0
 1 0 92 696972 274592 2358480 0 0 16 30 1667 161 21 38 42 1 0
 2 0 92 696352 274628 2358732 0 0 14 420 1702 151 20 36 42 1 0
 3 0 92 695096 274640 2359052 0 0 4 26 1624 193 27 57 16 0 0
 1 0 92 695220 274660 2359200 0 0 10 40 1635 138 22 40 38 1 0
 1 0 92 694840 274688 2359464 0 0 8 432 1625 175 21 34 43 2 0
 1 0 92 694228 274700 2359788 0 0 4 2 1670 163 21 35 44 1 0
 1 0 92 693616 274708 2360052 0 0 2 454 1730 141 20 36 45 0 0
 1 0 92 692872 274736 2360232 0 0 14 26 1630 158 21 34 44 1 0
 1 0 92 692252 274748 2360408 0 0 6 2 1634 143 24 42 34 0 0
 1 0 92 691756 274764 2360680 0 0 2 388 1655 126 22 34 43 1 0
 1 0 92 691508 274768 2360684 0 0 0 232 1753 118 25 36 39 0 0
 1 0 92 691136 274772 2360804 0 0 0 254 1640 118 21 35 45 0 0
 1 0 92 690888 274776 2361028 0 0 0 26 1647 134 19 35 46 0 0
 1 0 92 690392 274780 2361248 0 0 2 0 1719 116 20 44 36 0 0
 1 0 92 689772 274784 2361300 0 0 0 320 1678 164 21 46 32 0 0
 1 0 92 689772 274792 2361452 0 0 2 60 1792 129 18 36 46 0 0
 1 0 92 689276 274812 2361632 0 0 4 272 1744 130 19 37 44 0 0
 3 0 92 688384 274820 2361788 0 0 0 14 1700 117 22 40 38 0 0
 1 0 92 688276 274824 2361952 0 0 0 46 1600 153 26 56 18 0 0
 1 0 92 688028 274832 2362144 0 0 0 238 1655 118 20 34 46 1 0
 1 0 92 687780 274844 2362256 0 0 2 70 1648 128 19 34 46 0 0
 1 0 92 687408 274860 2362372 0 0 4 212 1640 130 20 34 46 0 0
 1 0 92 687292 274864 2362508 0 0 2 0 1694 102 18 34 48 0 0

>> My cache dir directive looks like:
>> cache_dir ufs /var/spool/squid 16384 64 1024
>>

> Make sure your Squid can support it (check the output of "squid -v" for
> aufs) and change this line to...

> cache_dir aufs /var/spool/squid 16384 64 1024

> ...to enable asynchronous cache accesses.

Did it. But the same thing (1 core load ~100%).

>> # vmstat -d
>> vmstat -d
>> disk- ------------reads------------ ------------writes----------- -----IO------
>> total merged sectors ms total merged sectors ms cur sec
>> ram0 0 0 0 0 0 0 0 0 0 0
>> ram1 0 0 0 0 0 0 0 0 0 0
>> ram2 0 0 0 0 0 0 0 0 0 0
>> ram3 0 0 0 0 0 0 0 0 0 0
>> ram4 0 0 0 0 0 0 0 0 0 0
>> ram5 0 0 0 0 0 0 0 0 0 0
>> ram6 0 0 0 0 0 0 0 0 0 0
>> ram7 0 0 0 0 0 0 0 0 0 0
>> ram8 0 0 0 0 0 0 0 0 0 0
>> ram9 0 0 0 0 0 0 0 0 0 0
>> ram10 0 0 0 0 0 0 0 0 0 0
>> ram11 0 0 0 0 0 0 0 0 0 0
>> ram12 0 0 0 0 0 0 0 0 0 0
>> ram13 0 0 0 0 0 0 0 0 0 0
>> ram14 0 0 0 0 0 0 0 0 0 0
>> ram15 0 0 0 0 0 0 0 0 0 0
>> sda 50114 8198 1197972 239114 771044 986524 13061742 1616345 0 1239
>> sdb 125 1430 2383 100 3 20 184 43 0 0
>> sdc 547181 13909 6116481 6209599 2893943 6771249 77505040 42580590 0 8027
>> dm-0 6659 0 143594 45401 528574 0 4228592 1248409 0 269
>> dm-1 13604 0 408122 82828 883993 0 7071944 3118925 0 677
>> dm-2 150 0 1132 387 2 0 10 2 0 0
>> dm-3 36240 0 639146 173982 178529 0 1428232 540632 0 229
>> dm-4 164 0 1136 610 35 0 76 155 0 0
>> dm-5 216 0 1240 817 166439 0 332884 262910 0 185
>> hda 0 0 0 0 0 0 0 0 0 0
>> fd0 0 0 0 0 0 0 0 0 0 0
>> md0 0 0 0 0 0 0 0 0 0 0
>>

> Right. Unless it's mounted as part of a logical volume, NFS doesn't
> show up here.

Squid cache is on sdc disk. There is no other partitions on sdc except
squid cache.

Regards,
Nikita.
Received on Mon Jan 26 2009 - 04:45:07 MST