1，测试环境
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www.htz.pw > !lsb_release -a LSB Version: :core-4.0-amd64:core-4.0-ia32:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-ia32:printing-4.0-noarch Distributor ID: RedHatEnterpriseServer Description: Red Hat Enterprise Linux Server release 4.8 (Tikanga) Release: 4.8 Codename: Tikanga
www.htz.pw > select * from v$version where rownum<3;
BANNER —————————————————————- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 – 64bi PL/SQL Release 10.2.0.5.0 – Production |
2，数据库中修改指定进程的调度策略
linux环境中进程调度的策略有如下几种：
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普通的分时策略 TS SCHED_OTHER 实时FIFO的策略 FF SCHED_FIFO 实时时间片策略 RR SCHED_RR 普通批处理策略 B SCHED_BATCH |
下面lgwr为例在数据库中修改进程的调度策略
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[root@www.htz.pw ~]#ps -Acfl|head -1;ps -Acfl|grep lgwr F S UID PID PPID CLS PRI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22959 1 TS 24 – 70706 – Jul17 ? 00:00:00 asm_lgwr_+ASM 0 S oracle 26054 1 TS 41 – 190806 – 05:26 ? 00:00:00 ora_lgwr_asm10g 0 R root 26227 26114 TS 21 – 15296 – 05:53 pts/4 00:00:00 grep lgwr
www.htz.pw > alter system set "_high_priority_processes"="LMS*|LGWR" scope=spfile;
System altered.
www.htz.pw > startup force; ORACLE instance started.
Total System Global Area 599785472 bytes Fixed Size 2098112 bytes Variable Size 163580992 bytes Database Buffers 427819008 bytes Redo Buffers 6287360 bytes Database mounted. Database opened. www.htz.pw > show parameter high
NAME TYPE ———————————— ———– VALUE —————————— _high_priority_processes string LMS*|LGWR
[root@www.htz.pw ~]#ps -Acfl|head -1;ps -Acfl|grep lgwr F S UID PID PPID CLS PRI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22959 1 TS 24 – 70706 – Jul17 ? 00:00:00 asm_lgwr_+ASM 0 S oracle 26054 1 RR 41 – 190806 – 05:26 ? 00:00:00 ora_lgwr_asm10g 0 R root 26227 26114 TS 21 – 15296 – 05:53 pts/4 00:00:00 grep lgwr |
这里可以看到lgwr的调试策略已经更改为RR模式。
3，操作系统更改进程调度模式
在操作以上面我们也可以通过chrt来更改进程的调度模式，不过只能在root用户下面执行，下面以dbw为例
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[root@www.htz.pw ~]#chrt -r -p 1 26052 [root@www.htz.pw ~]#ps -Afl|head -1;ps -Afl|grep dbw F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22957 1 0 75 0 – 71540 – Jul17 ? 00:00:00 asm_dbw0_+ASM 0 S oracle 26052 1 0 58 – – 186310 – 05:26 ? 00:00:00 ora_dbw0_asm10g 0 R root 26555 26114 0 79 0 – 15296 – 06:42 pts/4 00:00:00 grep dbw [root@www.htz.pw ~]#ps -Afcl|head -1;ps -Afcl|grep dbw F S UID PID PPID CLS PRI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22957 1 TS 24 – 71540 – Jul17 ? 00:00:00 asm_dbw0_+ASM 0 S oracle 26052 1 RR 41 – 186310 – 05:26 ? 00:00:00 ora_dbw0_asm10g 0 R root 26559 26114 TS 20 – 15296 – 06:42 pts/4 00:00:00 grep dbw |
下面将dbw进程调度模式从RR更改TS
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[root@www.htz.pw ~]#chrt –other -p 0 26052 [root@www.htz.pw ~]#ps -Afcl|head -1;ps -Afcl|grep dbw F S UID PID PPID CLS PRI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22957 1 TS 24 – 71540 – Jul17 ? 00:00:00 asm_dbw0_+ASM 0 S oracle 26052 1 TS 29 – 186310 – 05:26 ? 00:00:00 ora_dbw0_asm10g 0 R root 26586 26114 TS 20 – 15296 – 06:47 pts/4 00:00:00 grep db |
3，renice更改进程优先级
renice只能在root用户下才能提高进程优先级，普通用户下只能降低进程的优化先级
下面两样以dbw进程为例
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[root@www.htz.pw ~]#ps -Afcl|head -1;ps -Afcl|grep dbw F S UID PID PPID CLS PRI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22957 1 TS 24 – 71540 – Jul17 ? 00:00:00 asm_dbw0_+ASM 0 S oracle 26052 1 TS 29 – 186310 – 05:26 ? 00:00:00 ora_dbw0_asm10g 0 R root 26532 26114 TS 20 – 15296 – 06:37 pts/4 00:00:00 grep dbw [root@www.htz.pw ~]#ps -Afl|head -1;ps -Afl|grep dbw F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22957 1 0 75 0 – 71540 – Jul17 ? 00:00:00 asm_dbw0_+ASM 0 S oracle 26052 1 0 75 0 – 186310 – 05:26 ? 00:00:00 ora_dbw0_asm10g 0 R root 26522 26114 0 79 0 – 15296 – 06:36 pts/4 00:00:00 grep dbw |
这里看到DBW进程的调度策略为TS，NI的值为0，下面我们将NI的更改为–5
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[root@www.htz.pw ~]#renice -5 -p 26052 26052: old priority 0, new priority -5 [root@www.htz.pw ~]#ps -Afl|head -1;ps -Afl|grep dbw F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22957 1 0 75 0 – 71540 – Jul17 ? 00:00:00 asm_dbw0_+ASM 0 S oracle 26052 1 0 70 -5 – 186310 – 05:26 ? 00:00:00 ora_dbw0_asm10g |
这里看到renice已经修改成功。
不过这里需要注意的是，renice修改进程的调试模式为RR时，提示修改成功，但是使用命令无法查看。
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[root@www.htz.pw ~]#ps -Afcl|head -1;ps -Afcl|grep lgw F S UID PID PPID CLS PRI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22959 1 TS 24 – 70706 – Jul17 ? 00:00:00 asm_lgwr_+ASM 0 S oracle 26054 1 RR 80 – 190806 – 05:26 ? 00:00:00 ora_lgwr_asm10g 0 R root 26541 26114 TS 20 – 15296 – 06:39 pts/4 00:00:00 grep lgw [root@www.htz.pw ~]#renice -5 -p 26054 26054: old priority -5, new priority -5 [root@www.htz.pw ~]#ps -Afl|head -1;ps -Afl|grep lgw F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 0 S oracle 22959 1 0 75 0 – 70706 – Jul17 ? 00:00:00 asm_lgwr_+ASM 0 S oracle 26054 1 0 19 – – 190806 – 05:26 ? 00:00:00 ora_lgwr_asm10g 0 R root 26546 26114 0 79 0 – 15296 – 06:40 pts/4 00:00:00 grep lgw |
linux环境ORACLE进程调度策略与优先级：等您坐沙发呢！