Oralceswap100 % Case Analysis

Operating system version: CentOS5.864bit. Recently, the database is added with 32 GB memory, and the MEMORY_MAX_SIZE parameter is increased to 28 GB, And the MEMORY_TARGET parameter is 24 GB. Run

Operating system version: CentOS 5.8 64bit. Recently, the database is added with 32 GB of memory, and the MEMORY_MAX_SIZE parameter is increased to 28 GB, And the MEMORY_TARGET parameter is 24 GB. Run

Operating system version: CentOS 5.8 64bit

Database Version: 11.2.0.1

Problem description:

Recently, the database was added to 32 GB of memory, and the MEMORY_MAX_SIZE parameter was increased to 28 GB, And the MEMORY_TARGET parameter was changed to 24 GB. After a short operation, no major problems were found, the usage of swap monitored by nagios to the master and slave databases is high, but this does not happen before the memory is added. The operating system memory size before adjustment is 16 GB, after adjustment, the MEMORY_MAX_SIZE and MEMORY_TARGET parameters are both 11 GB!

Swap partition usage before adjustment:

1: The average usage of swap partitions in the master database is 7.11%.
[Root @ db1 ~] # Sar-f/var/log/sa/sa11-r
11:41:01 kbmemfree kbmemused % memused kbbuffers kbcached kbswpfree kbswpused % swpused kbswpcad
11:42:01 93760 16332056 99.43 124792 13621548 7610880 582260 7.11 280
11:43:01 87104 16338712 99.47 125084 13622556 7610880 582260 7.11 280
11:44:01 79484 16346332 99.52 125384 13624140 7610880 582260 7.11 280
11:45:01 77632 16348184 99.53 125684 13625580 7610880 582260 7.11 280
11:46:01 62852 16362964 99.62 125936 13634280 7610880 582260 7.11 280
11:47:01 58452 16367364 99.64 126484 13635080 7610880 582260 7.11 280
11:48:01 61328 16364488 99.63 126856 13639772 7610880 582260 7.11 280
11:49:01 64116 16361700 99.61 127040 13630580 7610880 582260 7.11 280
11:50:01 65820 16359996 99.60 127268 13625496 7610880 582260 7.11 280
11:51:01 59888 16365928 99.64 127148 13588072 7610880 582260 7.11 280
11:52:01 84152 16341664 99.49 127412 13589552 7610880 582260 7.11 280
11:53:01 102492 16323324 99.38 127716 13590332 7610880 582260 7.11 280
11:54:01 96444 16329372 99.41 128076 13602516 7610880 582260 7.11 280
11:55:01 88752 16337064 99.46 128408 13607108 7610880 582260 7.11 280
11:56:01 78936 16346880 99.52 128708 13608816 7610880 582260 7.11 280
11:57:01 57192 16368624 99.65 128936 13609668 7610880 582260 7.11 280
11:58:01 64308 16361508 99.61 129192 13611012 7610880 582260 7.11 280
11:59:01 62620 16363196 99.62 129476 13612704 7610880 582260 7.11 280
Average: 94185 16331631 99.43 125388 13559392 7610581 582559 7.11 289

2: The average usage of swap partitions in the standby database is 12.27%.
11:41:01 kbmemfree kbmemused % memused kbbuffers kbcached kbswpfree kbswpused % swpused kbswpcad
11:42:01 97084 16328732 99.41 283368 14770184 7187548 1005592 12.27 23924
11:43:01 95968 16329848 99.42 283396 14770264 7187548 1005592 12.27 23924
11:44:01 96760 16329056 99.41 283440 14770392 7187548 1005592 12.27 23924
11:45:01 94872 16330944 99.42 283480 14770532 7187548 1005592 12.27 23924
11:46:01 95392 16330424 99.42 283520 14770680 7187548 1005592 12.27 23924
11:47:01 90196 16335620 99.45 283568 14776592 7187548 1005592 12.27 23924
11:48:01 91524 16334292 99.44 283596 14778728 7187548 1005592 12.27 23924
11:49:01 91256 16334560 99.44 283648 14778792 7187552 1005588 12.27 23920
11:50:01 92560 16333256 99.44 283712 14778824 7187552 1005588 12.27 23920
11:51:01 90748 16335068 99.45 283772 14778912 7187552 1005588 12.27 23920
11:52:01 91484 16334332 99.44 283800 14779068 7187552 1005588 12.27 23920
11:53:01 89964 16335852 99.45 283844 14779136 7187572 1005568 12.27 23944
11:54:01 80092 16345724 99.51 283980 14790212 7187572 1005568 12.27 23944
11:55:01 72728 16353088 99.56 284052 14792660 7187572 1005568 12.27 23944
11:56:01 72300 16353516 99.56 284092 14792844 7187612 1005528 12.27 23936
11:57:01 72264 16353552 99.56 284152 14792908 7187612 1005528 12.27 23936
11:58:01 73680 16352136 99.55 284248 14793040 7187612 1005528 12.27 23936
11:59:01 73836 16351980 99.55 284300 14793172 7187612 1005528 12.27 23936
Average: 71240 16354576 99.57 265982 14818731 7172819 1020321 12.45 23450

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