合 Oracle新建实例后需要做哪些基本优化操作
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OS配置
关闭透明大页
不建议对数据库工作负载使用 THP （Oracle、MySQL、PostgreSQL、MongoDB均建议关闭THP），因为THP在运行时动态分配内存，而运行时的内存分配会有延迟，对于数据库的管理来说并不友好，会导致数据库性能抖动，所以建议关闭THP。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | cat /sys/kernel/mm/transparent_hugepage/defrag cat /sys/kernel/mm/transparent_hugepage/enabled echo never > /sys/kernel/mm/transparent_hugepage/enabled echo never > /sys/kernel/mm/transparent_hugepage/defrag cat >> /etc/rc.local <<"EOF" if test -f /sys/kernel/mm/transparent_hugepage/enabled; then echo never > /sys/kernel/mm/transparent_hugepage/enabled fi if test -f /sys/kernel/mm/transparent_hugepage/defrag; then echo never > /sys/kernel/mm/transparent_hugepage/defrag fi EOF chmod +x /etc/rc.d/rc.local |
开启标准大页
Huge Page使用2MB的大页代替传统小页4KB来管理内存，这样页表大小就可以得到控制。
参考：https://www.xmmup.com/oracleshujukupeizhidaye.html
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | -- 页表大小 [root@app-rac1 ~]# cat /proc/meminfo | grep PageTables PageTables: 38461088 kB cat >> /etc/security/limits.conf <<"EOF" * soft memlock -1 * hard memlock -1 EOF cat /etc/security/limits.conf alter system set MEMORY_TARGET=0 scope=spfile sid='*'; alter system set MEMORY_MAX_TARGET=0 scope=spfile sid='*'; alter system reset memory_target scope=spfile ; alter system reset memory_max_target scope=spfile ; cat > hugepages_settings.sh <<"EOF" #!/bin/bash # # hugepages_settings.sh # # Linux bash script to compute values for the # recommended HugePages/HugeTLB configuration # on Oracle Linux # # Note: This script does calculation for all shared memory # segments available when the script is run, no matter it # is an Oracle RDBMS shared memory segment or not. # # This script is provided by Doc ID 401749.1 from My Oracle Support # http://support.oracle.com # Welcome text echo " This script is provided by Doc ID 401749.1 from My Oracle Support (http://support.oracle.com) where it is intended to compute values for the recommended HugePages/HugeTLB configuration for the current shared memory segments on Oracle Linux. Before proceeding with the execution please note following: * For ASM instance, it needs to configure ASMM instead of AMM. * The 'pga_aggregate_target' is outside the SGA and you should accommodate this while calculating the overall size. * In case you changes the DB SGA size, as the new SGA will not fit in the previous HugePages configuration, it had better disable the whole HugePages, start the DB with new SGA size and run the script again. And make sure that: * Oracle Database instance(s) are up and running * Oracle Database 11g Automatic Memory Management (AMM) is not setup (See Doc ID 749851.1) * The shared memory segments can be listed by command: # ipcs -m Press Enter to proceed..." read # Check for the kernel version KERN=`uname -r | awk -F. '{ printf("%d.%d\n",$1,$2); }'` # Find out the HugePage size HPG_SZ=`grep Hugepagesize /proc/meminfo | awk '{print $2}'` if [ -z "$HPG_SZ" ];then echo "The hugepages may not be supported in the system where the script is being executed." exit 1 fi # Initialize the counter NUM_PG=0 # Cumulative number of pages required to handle the running shared memory segments for SEG_BYTES in `ipcs -m | cut -c44-300 | awk '{print $1}' | grep "[0-9][0-9]*"` do MIN_PG=`echo "$SEG_BYTES/($HPG_SZ*1024)" | bc -q` if [ $MIN_PG -gt 0 ]; then NUM_PG=`echo "$NUM_PG+$MIN_PG+1" | bc -q` fi done RES_BYTES=`echo "$NUM_PG * $HPG_SZ * 1024" | bc -q` # An SGA less than 100MB does not make sense # Bail out if that is the case if [ $RES_BYTES -lt 100000000 ]; then echo "***********" echo "** ERROR **" echo "***********" echo "Sorry! There are not enough total of shared memory segments allocated for HugePages configuration. HugePages can only be used for shared memory segments that you can list by command: # ipcs -m of a size that can match an Oracle Database SGA. Please make sure that: * Oracle Database instance is up and running * Oracle Database 11g Automatic Memory Management (AMM) is not configured" exit 1 fi # Finish with results case $KERN in '2.4') HUGETLB_POOL=`echo "$NUM_PG*$HPG_SZ/1024" | bc -q`; echo "Recommended setting: vm.hugetlb_pool = $HUGETLB_POOL" ;; '2.6') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '3.8') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '3.10') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '4.1') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '4.14') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '4.18') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '5.4') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; *) echo "Kernel version $KERN is not supported by this script (yet). Exiting." ;; esac # End EOF chmod +x hugepages_settings.sh ./hugepages_settings.sh echo -e 'vm.nr_hugepages=81922' >> /etc/sysctl.conf -- echo 81922 > /proc/sys/vm/nr_hugepages -- 重启数据库和主机 cat /proc/meminfo | grep PageTables cat /proc/meminfo |grep Huge free -h |
参数配置
修改sga_target、processes等
1 2 3 4 5 6 7 8 9 10 11 | alter system set memory_max_target=0 scope=spfile; alter system set memory_target=0 scope=spfile; alter system set sga_max_size=10g scope=spfile; alter system set sga_target=10g scope=spfile; alter system set PGA_AGGREGATE_TARGET=5g; alter system set processes=10000 scope=spfile sid='*'; startup force |
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