Now let me reply it myself.
When I changed memory.limit_in_bytes=300M， it worked.
memeory before sql statment execution and after sql statement execution is:
[postgres@cent6 Desktop]$ free -m
total used free shared buffers cached
Mem: 2006 537 1469 0 30 242
-/+ buffers/cache: 265 1741
Swap: 4031 0 4031
[postgres@cent6 Desktop]$ free -m
total used free shared buffers cached
Mem: 2006 687 1318 0 27 388
-/+ buffers/cache: 272 1734
Swap: 4031 129 3902
[postgres@cent6 Desktop]$
Best Regards
2013/9/9 高健 <luckyjackgao@xxxxxxxxx>
Hello:Sorry for disturbing,In order to make my question clear,I wrote this one as a seperate question.If using cgroup, I can find wget work well.But , for postgresql, when I deal huge amount of data, it still report out of memory error. In fact I hope postgresql can work under a limit amount of memory.My test is as this:Step 1:To make memory limit through cgroup:[postgres@cent6 Desktop]$ cat /etc/cgconfig.conf...mount {cpuset = /cgroup/cpuset;cpu = /cgroup/cpu;cpuacct = /cgroup/cpuacct;memory = /cgroup/memory;devices = /cgroup/devices;freezer = /cgroup/freezer;net_cls = /cgroup/net_cls;blkio = /cgroup/blkio;}group test1 {perm {task{uid=postgres;gid=postgres;}admin{uid=root;gid=root;}} memory {memory.limit_in_bytes=30M;}}[postgres@cent6 Desktop]$[postgres@cent6 Desktop]$ cat /etc/cgrules.conf# /etc/cgrules.conf...#<user> <controllers> <destination>postgres memory test1/
#[postgres@cent6 Desktop]$[postgres@cent6 Desktop]$ chkconfig --list cgconfigcgconfig 0:off 1:off 2:on 3:on 4:on 5:on 6:off[postgres@cent6 Desktop]$ chkconfig --list cgredcgred 0:off 1:off 2:on 3:on 4:on 5:on 6:off[postgres@cent6 Desktop]$Step 2 :To see memory :[postgres@cent6 Desktop]$ free -mtotal used free shared buffers cachedMem: 2006 384 1622 0 26 138-/+ buffers/cache: 219 1787Swap: 4031 87 3944[postgres@cent6 Desktop]$
Step3: To start postgresql and deal with data:postgres=# select count(*) from test01;count-------0(1 row)postgres=# insert into test01 values(generate_series(1,614400),repeat( chr(int4(random()*26)+65),1024));Then, In psql client, I got:The connection to the server was lost. Attempting reset: Failed.!>In postgresql's log, I found:[postgres@cent6 pgsql]$ LOG: database system was shut down at 2013-09-09 16:20:29 CSTLOG: database system is ready to accept connectionsLOG: autovacuum launcher startedLOG: server process (PID 2697) was terminated by signal 9: KilledDETAIL: Failed process was running: insert into test01 values(generate_series(1,614400),repeat( chr(int4(random()*26)+65),1024));LOG: terminating any other active server processesWARNING: terminating connection because of crash of another server processDETAIL: The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.HINT: In a moment you should be able to reconnect to the database and repeat your command.FATAL: the database system is in recovery modeLOG: all server processes terminated; reinitializingLOG: database system was interrupted; last known up at 2013-09-09 17:35:42 CSTLOG: database system was not properly shut down; automatic recovery in progressLOG: redo starts at 1/9E807C90LOG: unexpected pageaddr 1/946BE000 in log file 1, segment 159, offset 7069696LOG: redo done at 1/9F6BDB50LOG: database system is ready to accept connectionsLOG: autovacuum launcher startedWhen I see dmesg, I can see:[postgres@cent6 Desktop]$ dmesg | grep post[ 2673] 500 2673 64453 200 0 0 0 postgres[ 2675] 500 2675 64494 79 0 0 0 postgres[ 2676] 500 2676 64453 75 0 0 0 postgres[ 2677] 500 2677 64453 77 0 0 0 postgres[ 2678] 500 2678 64667 80 0 0 0 postgres[ 2679] 500 2679 28359 72 0 0 0 postgres[ 2697] 500 2697 64764 100 0 0 0 postgres[ 2673] 500 2673 64453 200 0 0 0 postgres[ 2675] 500 2675 64494 79 0 0 0 postgres[ 2676] 500 2676 64453 75 0 0 0 postgres[ 2677] 500 2677 64453 77 0 0 0 postgres[ 2678] 500 2678 64667 80 0 0 0 postgres[ 2679] 500 2679 28359 72 0 0 0 postgres[ 2697] 500 2697 64764 100 0 0 0 postgres[ 2673] 500 2673 64453 208 0 0 0 postgres[ 2675] 500 2675 64494 79 0 0 0 postgres[ 2676] 500 2676 64453 98 0 0 0 postgres[ 2677] 500 2677 64453 782 0 0 0 postgres[ 2678] 500 2678 64667 133 0 0 0 postgres[ 2679] 500 2679 28359 86 0 0 0 postgres[ 2697] 500 2697 73075 3036 0 0 0 postgresMemory cgroup out of memory: Kill process 2697 (postgres) score 1000 or sacrifice childKilled process 2697, UID 500, (postgres) total-vm:292300kB, anon-rss:8432kB, file-rss:3712kB[postgres@cent6 Desktop]$Although I encountered the out of memory , but it is cgroup out of memory.I think that cgroup really influenced postgresql.But not by the means I hope: I hope PG can work under limit , not to be killed by OOM.My above sql statement quickly failed. that is: PG 's main process is killed by OOM because it is going to use memory more than 30M,which is limited by cgroup.But If I run wget, wget can work well under memory limit:So My question is:Wen under cgroup's memory limit , Why PG crashed but wget do not?Best Regards
