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How to diagnose a “context-switching ”

From: RD黄永卫 <yongwei_huang(at)temp(dot)gtmc(dot)com(dot)cn>
To: <pgsql-performance(at)postgresql(dot)org>,<pgsql-bugs-owner(at)postgresql(dot)org>
Subject: How to diagnose a “context-switching ”
Date: 2010-04-12 06:35:32
Message-ID: EDA3764BC9DBA043AABB8FF57D73237801B5CEE8@QFWA0016.gtmcl.com (view raw or flat)
Thread:
Lists: pgsql-performance
Hi,

    My database server get sluggish suddenly ,I check the vmstat as below:

 

2010-04-07 04:03:15 procs                      memory      swap          io     system         cpu

2010-04-07 04:03:15  r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa

2010-04-07 14:04:27  3  0      0 2361272 272684 3096148    0    0     3  1445  973 14230  7  8 84  0

2010-04-07 14:05:27  2  0      0 2361092 272684 3096220    0    0     3  1804 1029 31852  8 10 81  1

2010-04-07 14:06:27  1  0      0 2362236 272684 3096564    0    0     3  1865 1135 19689  9  9 81  0

2010-04-07 14:07:27  1  0      0 2348400 272720 3101836    0    0     3  1582 1182 149461 15 17 67  0

2010-04-07 14:08:27  3  0      0 2392028 272840 3107600    0    0     3  3093 1275 203196 24 23 53  1

2010-04-07 14:09:27  3  1      0 2386224 272916 3107960    0    0     3  2486 1331 193299 26 22 52  0

2010-04-07 14:10:27 34  0      0 2332320 272980 3107944    0    0     3  1692 1082 214309 24 22 54  0

2010-04-07 14:11:27  1  0      0 2407432 273028 3108092    0    0     6  2770 1540 76643 29 13 57  1

2010-04-07 14:12:27  9  0      0 2358968 273104 3108388    0    0     7  2639 1466 10603 22  6 72  1

 

   My postgres version: 8.1.3; 

My OS version: Linux version 2.4.21-47.Elsmp((Red Hat Linux 3.2.3-54)

My CPU:

processor       : 7

vendor_id       : GenuineIntel

cpu family      : 15

model           : 6

model name      : Intel(R) Xeon(TM) CPU 3.40GHz

stepping        : 8

cpu MHz         : 3400.262

cache size      : 1024 KB

physical id     : 1

 

 

I donnt know what make the “context-switching”  storm ? 

How should I investigate <javascript:;>   the real reason ?

Could you please give me some advice ? 

 

Best regards,

Ray Huang

 

 

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