[squid-users] TCP response time | Proxy efficiency | Paging .. pending questions

From: <vincent.blondel_at_ing.be>
Date: Tue, 25 Aug 2009 12:45:14 +0200

Hello all,

when looking on the good working of one of my squid proxies, I see some
values I think somewhat relevant for increasing the cache_mem.

next to my investigations I can see this machine receives some 130req/s,
sends some 80 req/s, caches some 1.2 million objects on disk. this is
the very basic part of it.

$ squidclient mgr:info
Internal Data Structures:
        1182755 StoreEntries
         70431 StoreEntries with MemObjects
         70365 Hot Object Cache Items
        1174685 on-disk objects

$ squidclient mgr:5min |egrep 'http|fault'
client_http.requests = 127.388482/sec
client_http.hits = 45.899453/sec
client_http.errors = 0.000000/sec
client_http.kbytes_in = 95.962190/sec
client_http.kbytes_out = 1820.344974/sec
client_http.all_median_svc_time = 0.021898 seconds
client_http.miss_median_svc_time = 0.042766 seconds
client_http.nm_median_svc_time = 0.001789 seconds
client_http.nh_median_svc_time = 0.020695 seconds
client_http.hit_median_svc_time = 0.004626 seconds
server.http.requests = 78.912393/sec
server.http.errors = 0.000000/sec
server.http.kbytes_in = 1285.901343/sec
server.http.kbytes_out = 66.245877/sec
page_faults = 0.043333/sec

we can also see a correct hit (36%) and byte (20%) rate on this server
but ...

* what does it mean "Proxy efficiency 46.01" ??
* and what does it mean "Average speed increase 24.27% " ??
* what does it mean "TCP response time of 100%% requests" ..
         ? the maximum time taken to make the SYN SYN/ACK ACK when
asking for a socket on the parent cahe
         ? the maximum time taken for getting an object from the parent
cache
         ???

Summary
Calamaris statistics
   
lines parsed: lines 15855657
invalid lines: lines 0
parse time: sec 4145
parse speed: lines/sec 3825
   
Proxy statistics
   
Total amount: requests 15855657
Total Bandwidth: Byte 165G
Proxy efficiency (HIT [kB/sec] / DIRECT [kB/sec]): factor 46.01
Average speed increase: % 24.27
TCP response time of 100%% requests: msec 1900
   
Cache statistics
   
Total amount cached: requests 5627335
Request hit rate: % 35.49
Bandwidth savings: Byte 33781M
Bandwidth savings in Percent (Byte hit rate): % 19.96
Average cached object size: Byte 6294
Average direct object size: Byte 13885
Average object size: Byte 11191

the machine squid is running on is a Sun Solaris 8 V210 with 2Gb memory.

$ prtconf
System Configuration: Sun Microsystems sun4u
Memory size: 2048 Megabytes
System Peripherals (Software Nodes):
SUNW,Sun-Fire-V210

concerning the memory usage this becomes much more unclear for me ... if
I good understand I see the process size is some 700mb and get some
600mb allocated. when going deeper in the vmstat stats pi and po column
respectively give 825 and 236 at some time ...

* is this not some too big value ??
* cache_mem is currently defined at 400mb, don't you think increasing
this value to a bigger value (let's say some 500-600 mb) would not be
better ??

$ squidclient mgr:info
Squid Object Cache: Version 2.7.STABLE4
Start Time: Mon, 17 Aug 2009 02:00:38 GMT
Current Time: Thu, 20 Aug 2009 10:48:06 GMT
Connection information for squid:
        Number of clients accessing cache: 2264
        Number of HTTP requests received: 11355087
        Number of ICP messages received: 11553839
        Number of ICP messages sent: 11564676
        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: 2342.5
        Average ICP messages per minute since start: 4769.2
        Select loop called: 94346313 times, 3.083 ms avg
Cache information for squid:
        Request Hit Ratios: 5min: 38.8%, 60min: 30.9%
        Byte Hit Ratios: 5min: 21.8%, 60min: 29.7%
        Request Memory Hit Ratios: 5min: 27.4%, 60min: 27.1%
        Request Disk Hit Ratios: 5min: 23.4%, 60min: 18.0%
        Storage Swap size: 29196377 KB
        Storage Mem size: 409632 KB
        Mean Object Size: 24.85 KB
        Requests given to unlinkd: 114
Median Service Times (seconds) 5 min 60 min:
        HTTP Requests (All): 0.02190 0.01035
        Cache Misses: 0.04047 0.03622
        Cache Hits: 0.00463 0.00379
        Near Hits: 0.01955 0.02317
        Not-Modified Replies: 0.00179 0.00179
        DNS Lookups: 0.00190 0.00190
        ICP Queries: 0.00221 0.00221
Resource usage for squid:
        UP Time: 290848.297 seconds
        CPU Time: 26579.690 seconds
        CPU Usage: 9.14%
        CPU Usage, 5 minute avg: 30.92%
        CPU Usage, 60 minute avg: 32.65%
        Process Data Segment Size via sbrk(): 693792 KB
        Maximum Resident Size: 0 KB
        Page faults with physical i/o: 19875
Memory accounted for:
        Total accounted: 603121 KB
        memPoolAlloc calls: 1390282241
        memPoolFree calls: 1384735607
File descriptor usage for squid:
        Maximum number of file descriptors: 8192
        Largest file desc currently in use: 801
        Number of file desc currently in use: 697
        Files queued for open: 0
        Available number of file descriptors: 7495
        Reserved number of file descriptors: 100
        Store Disk files open: 0
        IO loop method: poll

$ vmstat 5 5
 procs memory page disk faults
cpu
 r b w swap free re mf pi po fr de sr m0 m1 m3 m4 in sy cs us
sy id
 0 0 0 2614824 634360 62 277 76 29 29 0 0 3 0 3 5 4294967261 276
176 10 9 81
 0 0 0 2442720 414768 145 128 568 236 236 0 0 0 0 0 60 3418 15771 2959
31 30 39
 2 1 0 2442304 418104 296 851 739 75 75 0 0 27 0 1 20 2862 58159 2199
41 45 14
 0 0 0 2442720 423744 229 0 825 180 180 0 0 0 0 0 8 2749 36179 2911
36 28 36
 0 0 0 2442720 428832 146 0 452 96 96 0 0 0 0 1 4 3825 13153 2585
26 30 45

$ vmstat -i
interrupt total rate
--------------------------------
clock 1582676343 100
--------------------------------
Total 1582676343 100

$ vmstat -s
        0 swap ins
        0 swap outs
        0 pages swapped in
        0 pages swapped out
119188729 total address trans. faults taken
 63414018 page ins
 33261045 page outs
150679474 pages paged in
 57581487 pages paged out
985466858 total reclaims
985358256 reclaims from free list
        0 micro (hat) faults
119188729 minor (as) faults
 34878720 major faults
1518806042 copy-on-write faults
655083663 zero fill page faults
   187523 pages examined by the clock daemon
        0 revolutions of the clock hand
 57477049 pages freed by the clock daemon
 47526220 forks
   149015 vforks
 49086268 execs
3171912755 cpu context switches
1401743919 device interrupts
3042943801 traps
2429831033 system calls
1065243178 total name lookups (cache hits 87%)
151392974 user cpu
148588621 system cpu
1165931599 idle cpu
116763714 wait cpu

many thks to help me and do not hesitate to give me any comment about
the files give above.

Vincent.
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Received on Tue Aug 25 2009 - 10:45:25 MDT

This archive was generated by hypermail 2.2.0 : Wed Aug 26 2009 - 12:00:04 MDT