目前ClickHouse的表引擎主要有下麵四個系列，合併樹家族、日誌引擎系列、集成的表引擎和其他特殊的引擎。 #合併樹家族 Clickhouse中最強大的表引擎當屬MergeTree（合併樹）引擎及該系列（MergeTree）中的其他引擎。 MergeTree系列的引擎被設計用於插入極大量的數據到一 ...
[20221020]奇怪的增量備份.txt
--//生產系統做增量備份遇到的怪異問題,給奇葩的運維人員狠狠地涮了一把,做一個記錄:
1.環境:
[email protected]:1521/orcl> @ pr
==============================
PORT_STRING : x86_64/Linux 2.4.xx
VERSION : 19.0.0.0.0
BANNER : Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
BANNER_FULL : Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
BANNER_LEGACY : Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
CON_ID : 0
PL/SQL procedure successfully completed.
2.問題:
--//在rman下查看:
RMAN> list backupset 7868;
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
7868 Incr 1 4.47G SBT_TAPE 00:35:56 2022-10-20 00:26:15
BP Key: 8615 Status: AVAILABLE Compressed: NO Tag: 2022_10_19_23_50_13
Handle: ORDB_ORCL_7894_1_1118533819 Media:
List of Datafiles in backup set 7868
File LV Type Ckp SCN Ckp Time Abs Fuz SCN Sparse Name
---- -- ---- ---------- ------------------- ----------- ------ ----
1 1 Incr 42592240372 2022-10-19 23:50:19 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/system01.dbf
2 1 Incr 42592240372 2022-10-19 23:50:19 42592296511 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data.dbf
3 1 Incr 42592240372 2022-10-19 23:50:19 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/sysaux01.dbf
4 1 Incr 42592240372 2022-10-19 23:50:19 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/undotbs01.dbf
5 1 Incr 42592240372 2022-10-19 23:50:19 42592295965 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_data.dbf
7 1 Incr 42592240372 2022-10-19 23:50:19 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/users01.dbf
8 1 Incr 42592240372 2022-10-19 23:50:19 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data01.dbf
9 1 Incr 42592240372 2022-10-19 23:50:19 42592244778 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_data02.dbf
10 1 Incr 42592240372 2022-10-19 23:50:19 42592295898 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data02.dbf
11 1 Incr 42592240372 2022-10-19 23:50:19 42592268142 NO /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data03.dbf
--//不知道虛擬磁帶庫是否有文件大小的限制.目前4.47G.
[email protected]:1521/orcl> @ dashtop sql_id,module1 1=1 &day
Total
Seconds AAS %This SQL_ID MODULE1 FIRST_SEEN LAST_SEEN
--------- ------- ------- ------------- -------------------- ------------------- -------------------
7030 .1 22% 2022-10-11 10:56:18 2022-10-12 10:00:29
5090 .1 16% w3wp.exe 2022-10-11 10:56:18 2022-10-12 10:00:19
2180 .0 7% backup incr datafile 2022-10-11 23:50:09 2022-10-12 00:26:24
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1530 .0 5% backup archivelog 2022-10-12 00:27:04 2022-10-12 02:32:11
--//很明顯發現問題在於運維人員沒有打開塊跟蹤特性,導致要掃描整個數據文件,不然做增量level=1不會使用這麼長時間.
--//ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;
[email protected]:1521/orcl> SELECT * FROM V$BLOCK_CHANGE_TRACKING
2 @ pr
==============================
STATUS : DISABLED
FILENAME :
BYTES :
CON_ID :
PL/SQL procedure successfully completed.
[email protected]:1521/orcl> alter database enable block change tracking using file '/u01/app/oracle/oradata/orcl/changetracking/block_change_tracking.f' reuse;
Database altered.
[email protected]:1521/orcl> SELECT * FROM V$BLOCK_CHANGE_TRACKING
2 @pr
==============================
STATUS : ENABLED
FILENAME : /u01/app/oracle/oradata/orcl/changetracking/block_change_tracking.f
BYTES : 11599872
CON_ID : 0
PL/SQL procedure successfully completed.
--//幾天後檢查發現增量備份時間並沒有減少,我開始以為我自己禁用了塊跟蹤,但是我清晰的記得當時下班前我是打開的了.
--//我接著再次執行(我的工作筆記記錄的是上個星期4做的操作2022/10/20):
alter database enable block change tracking using file '/u01/app/oracle/oradata/orcl/changetracking/block_change_tracking.f' reuse;
--//這次應該可以了把.因為星期6,7應該有1次level=0的全備份.
--//可是今天上班檢查(星期1 2022/10/24)發現增量備份還是需要很長時間.難道我對backup incr datafile理解有誤.
--//難道是接著做增量的第1次level=1的增量備份還是無法使用,我給在測試環境測試看看.
[email protected]:1521/orcl> SELECT * FROM V$BLOCK_CHANGE_TRACKING
2 @ pr
==============================
STATUS : DISABLED
FILENAME :
BYTES :
CON_ID :
PL/SQL procedure successfully completed.
--//發現居然變成了DISABLED,難道有人不讓我enable block change tracking嗎?而且這次我不可能犯錯.
3.檢查跟蹤文件發現:
--//檢查發現實際上對方寫的腳本有1個alter database disable block change tracking操作,奇葩!!alert*.log有記錄:
2022-10-18T23:50:12.040797+08:00
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
alter database disable block change tracking
2022-10-18T23:50:12.057827+08:00
stopping change tracking
2022-10-18T23:50:12.058898+08:00
Block change tracking service stopping.
Stopping background process CTWR
2022-10-18T23:50:13.112232+08:00
Deleted file /u01/app/oracle/oradata/orcl/changetracking/block_change_tracking.f
Completed: alter database disable block change tracking
2022-10-19T00:25:54.803845+08:00
Control autobackup written to SBT_TAPE device
--//很明顯對方的增量備份腳本在備份前禁用了塊跟蹤文件特性,執行時間也能對上2022-10-18T23:50.12.
--//奇葩的運維人員....我根本不知道這位同行是如何想的,難道這位同行遇到什麼bug或者遇到這類增量方式無法恢復的情況.
--//連續浪費好幾天的時間檢查該問題,如果一開始查詢alert文件,問題很快就可以定位了.
