[20181112]11g 日志传输压缩模式.txt

[20181112]11g 日志传输压缩模式.txt --//由于主备库不在一个局域网内,一样采用级联模式,先传输日志到一台主机,然后在由这台备库传输日志到远端的dataguard备库. --//这样一定程度减轻主库负担,另外加快日志应用,这样影响小一点,另外一种方式日志传输模式采用压缩模式.以前自己也测试过. --//链接:http://blog.itpub.net/267265/viewspace-1143480/ --//工作需要,重复验证看看. 1.环境: SCOTT@book> @ ver1 PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production SCOTT@book> show parameter log_archive_dest_2 NAME               TYPE   VALUE ------------------ ------ ----------------------------------------------------------------------------------------------- log_archive_dest_2 string SERVICE=bookdg LGWR ASYNC AFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=bookdg SCOTT@book> alter system set log_archive_dest_2='SERVICE=bookdg LGWR ASYNC AFFIRM compression=enable VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=bookdg'; System altered. --//这样就ok了. 2.如何验证日志传输是压缩的呢? --//首先在主备库打开归档跟踪: --//主库: SCOTT@book> alter system set log_archive_trace=16; ystem altered. --//备库: SCOTT@bookdg> alter system set log_archive_trace=16; System altered. SYS@book> alter system archive log current; System altered. $ ps -ef | egrep "ns[a]|UI[D]" UID        PID  PPID  C STIME TTY          TIME CMD oracle   44236     1  0 09:05 ?        00:00:24 ora_nsa2_book --//nsa进程号44236 $ ls -l *44236*.trc -rw-r----- 1 oracle oinstall 46407479 2018-11-12 15:10:24 book_nsa2_44236.trc --//发现log_archive_trace=16;记录信息有点多. SYS@book> alter system set log_archive_trace=1; System altered. $ tail -f book_nsa2_44236.trc *** 2018-11-12 15:11:36.093 *** 2018-11-12 15:11:36.093 1274 krsu.c RFS message number 23059 (RFSWRITE) RTC: Compression ratio for this I/O is 81% *** 2018-11-12 15:11:37.094 *** 2018-11-12 15:11:37.094 1274 krsu.c RFS message number 23060 (RFSWRITE) RTC: Compression ratio for this I/O is 82% *** 2018-11-12 15:11:38.095 *** 2018-11-12 15:11:38.095 1274 krsu.c RFS message number 23061 (RFSWRITE) RTC: Compression ratio for this I/O is 80% *** 2018-11-12 15:11:39.096 *** 2018-11-12 15:11:39.096 1274 krsu.c RFS message number 23062 (RFSWRITE) RTC: Compression ratio for this I/O is 81% $ grep "RTC:" book_nsa2_44236.trc | sort|uniq -c       1 RTC: Compression ratio for this I/O is 77%       5 RTC: Compression ratio for this I/O is 79%      16 RTC: Compression ratio for this I/O is 80%      50 RTC: Compression ratio for this I/O is 81%      26 RTC: Compression ratio for this I/O is 82%       3 RTC: Compression ratio for this I/O is 83%       1 RTC: Compression ratio for this I/O is 85% --//可以发现压缩率非常高.产生一些事务看看: SCOTT@book> create table t as select * from dba_objects ; Table created. SCOTT@book> update t set OBJECT_NAME=lower(OBJECT_NAME); 86993 rows updated. SCOTT@book> commit ; Commit complete. $ grep "RTC:" book_nsa2_44236.trc | sort|uniq -c       1 RTC: Compression ratio for this I/O is 46%       1 RTC: Compression ratio for this I/O is 48%       1 RTC: Compression ratio for this I/O is 50%       4 RTC: Compression ratio for this I/O is 55%       1 RTC: Compression ratio for this I/O is 56%       1 RTC: Compression ratio for this I/O is 57%       3 RTC: Compression ratio for this I/O is 58%       1 RTC: Compression ratio for this I/O is 59%       1 RTC: Compression ratio for this I/O is 63%       1 RTC: Compression ratio for this I/O is 64%       2 RTC: Compression ratio for this I/O is 68%       1 RTC: Compression ratio for this I/O is 69%       4 RTC: Compression ratio for this I/O is 72%       3 RTC: Compression ratio for this I/O is 74%       1 RTC: Compression ratio for this I/O is 75%       5 RTC: Compression ratio for this I/O is 76%       5 RTC: Compression ratio for this I/O is 77%       6 RTC: Compression ratio for this I/O is 78%      20 RTC: Compression ratio for this I/O is 79%      66 RTC: Compression ratio for this I/O is 80%      99 RTC: Compression ratio for this I/O is 81%      50 RTC: Compression ratio for this I/O is 82%      19 RTC: Compression ratio for this I/O is 83%      21 RTC: Compression ratio for this I/O is 84%       4 RTC: Compression ratio for this I/O is 85% --//压缩率也能达到50%以上. 3.在备库观察: SYS@bookdg> @ &r/dg/dg PROCESS       PID STATUS       CLIENT_P GROUP#  THREAD#  SEQUENCE#     BLOCK#     BLOCKS DELAY_MINS --------- ------- ------------ -------- ------- ------- ---------- ---------- ---------- ---------- RFS         28207 IDLE         ARCH     N/A           0          0          0          0          0 ARCH        28364 CONNECTED    ARCH     N/A           0          0          0          0          0 RFS         28205 IDLE         LGWR     1             1        731        251          1          0 ARCH        28362 CLOSING      ARCH     4             1        727          1        513          0 ARCH        28360 CLOSING      ARCH     5             1        728      73728       1902          0 ARCH        28366 CLOSING      ARCH     5             1        730      88064       1750          0 MRP0        28162 APPLYING_LOG N/A      N/A           1        731        251     102400          0 7 rows selected. --//可以确定接收的进程当前是28205. 备库: $ grep RTC: bookdg_rfs_28205.trc | less ... RTC: decompressed 232440 bytes to 1048576 bytes RTC: decompressed 785 bytes to 3072 bytes RTC: decompressed 222314 bytes to 1048576 bytes RTC: decompressed 1396 bytes to 5120 bytes RTC: decompressed 217892 bytes to 1048576 bytes RTC: decompressed 1564 bytes to 5632 bytes RTC: decompressed 223295 bytes to 1048576 bytes RTC: decompressed 115 bytes to 512 bytes RTC: decompressed 189832 bytes to 1048576 bytes RTC: decompressed 2941 bytes to 14848 bytes RTC: decompressed 192267 bytes to 1048576 bytes RTC: decompressed 610 bytes to 2560 bytes RTC: decompressed 192315 bytes to 1048576 bytes RTC: decompressed 531 bytes to 2048 bytes RTC: decompressed 191932 bytes to 1048576 bytes RTC: decompressed 597 bytes to 2560 bytes RTC: decompressed 193008 bytes to 1048576 bytes RTC: decompressed 655 bytes to 2560 bytes RTC: decompressed 5732 bytes to 28160 bytes RTC: decompressed 194474 bytes to 1048576 bytes RTC: decompressed 591 bytes to 2560 bytes RTC: decompressed 174682 bytes to 1048576 bytes RTC: decompressed 505 bytes to 2560 bytes RTC: decompressed 4911 bytes to 27648 bytes RTC: decompressed 159418 bytes to 1048576 bytes RTC: decompressed 249 bytes to 1024 bytes RTC: decompressed 4773 bytes to 27648 bytes RTC: decompressed 162834 bytes to 1048576 bytes RTC: decompressed 532 bytes to 2560 bytes RTC: decompressed 162426 bytes to 1048576 bytes RTC: decompressed 566 bytes to 2560 bytes RTC: decompressed 4941 bytes to 28160 bytes RTC: decompressed 160794 bytes to 1048576 bytes RTC: decompressed 279 bytes to 1024 bytes RTC: decompressed 5578 bytes to 32256 bytes RTC: decompressed 163626 bytes to 1048576 bytes RTC: decompressed 561 bytes to 2560 bytes RTC: decompressed 4761 bytes to 27136 bytes RTC: decompressed 159520 bytes to 1048576 bytes RTC: decompressed 559 bytes to 2560 bytes RTC: decompressed 4918 bytes to 28672 bytes RTC: decompressed 160996 bytes to 1048576 bytes RTC: decompressed 281 bytes to 1024 bytes RTC: decompressed 159494 bytes to 1048576 bytes RTC: decompressed 160961 bytes to 1048576 bytes RTC: decompressed 13209 bytes to 84992 bytes RTC: decompressed 159411 bytes to 1048576 bytes RTC: decompressed 154267 bytes to 836608 bytes RTC: decompressed 205968 bytes to 1048576 bytes RTC: decompressed 192858 bytes to 1048576 bytes RTC: decompressed 201346 bytes to 1048576 bytes RTC: decompressed 15110 bytes to 78336 bytes RTC: decompressed 202438 bytes to 1048576 bytes RTC: decompressed 204217 bytes to 1048576 bytes --//从解压看,压缩比率还是蛮大的 4.RTC表示什么,猜测一下: --//RTC应该表示redo transport compression 5.收尾: SCOTT@book> alter system reset log_archive_trace; System altered. SYS@bookdg> alter system reset log_archive_trace; System altered. SYS@book> alter system set log_archive_dest_2='SERVICE=bookdg LGWR ASYNC AFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=bookdg'; System altered. --//重启主备库.略.