| Bug #44068 | RESTORE can disable the MyISAM Key Cache | ||
|---|---|---|---|
| Submitted: | 3 Apr 2009 8:26 | Modified: | 25 Apr 2009 23:54 |
| Reporter: | Ingo Strüwing | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Backup | Severity: | S2 (Serious) |
| Version: | 6.0 | OS: | Any |
| Assigned to: | Ingo Strüwing | CPU Architecture: | Any |
[3 Apr 2009 8:31]
Ingo Strüwing
Suggested triage values: Defect: serious. Disabling the MyISAM key cache is a serious problem. Workaround: unacceptable. One could reactivate the cache after restore by setting a new cache size. Impact: widespread. MyISAM is in wide use. Restoring of MyISAM tables is expected to be a frequent operation.
[3 Apr 2009 9:45]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/71299 2810 Ingo Struewing 2009-04-03 Bug#44068 - RESTORE can disable the MyISAM Key Cache The test case myisam_keycache_coverage used to fail if it ran after backup_myisam_sync. The reason was that the latter test case disabled the key cache during RESTORE. The error injection in myisam_keycache_coverage became void as the key cache wasn't used any more. Reads of the index file bypassed the cache, and the statements succeeded. Fixed by avoiding de-initialization of the key cache if it was not initialized by the MyISAM log reading function mi_examine_log(). The function will initialize and de-initialize the key cache if it is used by the myisamlog utility. It won't touch the key cache any more, if it is called from inside the server. Additional change: To make the state of the key cache visible, I added cleanup for the status variables blocks_used and blocks_unused. This improves the testability. @ mysql-test/r/myisam_keycache_coverage.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/r/backup_myisam_sync.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/t/backup_myisam_sync.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added checks for the state of the key cache. @ mysql-test/t/myisam_keycache_coverage.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added debug variable initialization to be safe. Added FORCE INDEX to the reference statement to make it equal to the tested statement. Removed old attempts to stabilize the test case. @ mysys/mf_keycache.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Added cleanup for blocks_used and blocks_unused. Added DBUG. @ storage/myisam/mi_examine_log.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Added local variable key_cache_blocks to be used to call end_key_cache() only if init_key_cache() did in fact initialize the cache.
[7 Apr 2009 19:05]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/71579 2810 Ingo Struewing 2009-04-07 Bug#44068 - RESTORE can disable the MyISAM Key Cache The test case myisam_keycache_coverage used to fail if it ran after backup_myisam_sync. The reason was that the latter test case disabled the key cache during RESTORE. The error injection in myisam_keycache_coverage became void as the key cache wasn't used any more. Reads of the index file bypassed the cache, and the statements succeeded. Fixed by moving initialization and de-initialization of the key cache from mi_examine_log() to myisamlog. In the server, the initialization is already done. Additional change: To make the state of the key cache visible, I added cleanup for the status variables blocks_used and blocks_unused. This improves the testability. @ mysql-test/r/myisam_keycache_coverage.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/r/backup_myisam_sync.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/t/backup_myisam_sync.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added checks for the state of the key cache. @ mysql-test/t/myisam_keycache_coverage.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added FORCE INDEX to the reference statement to make it equal to the tested statement. Removed old attempts to stabilize the test case. Added proper set and unset of the debug variable to disturb debugging as little as possible. @ mysys/mf_keycache.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Added cleanup for blocks_used and blocks_unused. Added DBUG. @ storage/myisam/mi_examine_log.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from here to myisamlog.c @ storage/myisam/myisamlog.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from mi_examine_log.c to here.
[14 Apr 2009 10:36]
Rafal Somla
Good to push.
[14 Apr 2009 13:40]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/72007 2810 Ingo Struewing 2009-04-14 Bug#44068 - RESTORE can disable the MyISAM Key Cache The test case myisam_keycache_coverage used to fail if it ran after backup_myisam_sync. The reason was that the latter test case disabled the key cache during RESTORE. The error injection in myisam_keycache_coverage became void as the key cache wasn't used any more. Reads of the index file bypassed the cache, and the statements succeeded. Fixed by moving initialization and de-initialization of the key cache from mi_examine_log() to myisamlog. In the server, the initialization is already done. Additional change: To make the state of the key cache visible, I added cleanup for the status variables blocks_used and blocks_unused. This improves the testability. @ mysql-test/r/myisam_keycache_coverage.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/r/backup_myisam_sync.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/t/backup_myisam_sync.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added checks for the state of the key cache. @ mysql-test/t/myisam_keycache_coverage.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added FORCE INDEX to the tested statement. Removed old attempts to stabilize the test case. Added proper resetting of the debug variable to disturb debugging as little as possible. Removed clearing of the debug variable. @ mysys/mf_keycache.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Added cleanup for blocks_used and blocks_unused. Added DBUG. @ storage/myisam/mi_examine_log.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from here to myisamlog.c @ storage/myisam/myisamlog.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from mi_examine_log.c to here.
[14 Apr 2009 15:07]
Ingo Strüwing
Queued to 6.0-backup.
[23 Apr 2009 7:19]
Bugs System
Pushed into 6.0.11-alpha (revid:alik@sun.com-20090423070920-e5lq3vrrqi016z2c) (version source revid:alik@sun.com-20090423070920-e5lq3vrrqi016z2c) (merge vers: 6.0.11-alpha) (pib:6)
[25 Apr 2009 23:54]
Paul DuBois
Noted in 6.0.11 changelog. A RESTORE operation that restored a MyISAM table using the native MyISAM restore driver could cause the MyISAM key cache to be disabled.
[31 Dec 2009 19:09]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/95842 3020 Ingo Struewing 2009-12-31 WL#5101 - MySQL Backup back port - MS09 Merged revid:ingo.struewing@sun.com-20090414134006-e8sgm8i1ncf3hzkp Bug#44068 - RESTORE can disable the MyISAM Key Cache The test case myisam_keycache_coverage used to fail if it ran after backup_myisam_sync. The reason was that the latter test case disabled the key cache during RESTORE. The error injection in myisam_keycache_coverage became void as the key cache wasn't used any more. Reads of the index file bypassed the cache, and the statements succeeded. Fixed by moving initialization and de-initialization of the key cache from mi_examine_log() to myisamlog. In the server, the initialization is already done. Additional change: To make the state of the key cache visible, I added cleanup for the status variables blocks_used and blocks_unused. This improves the testability. @ mysql-test/r/myisam_keycache_coverage.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/r/backup_myisam_sync.result Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/suite/backup/t/backup_myisam_sync.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added checks for the state of the key cache. @ mysql-test/t/myisam_keycache_coverage.test Bug#44068 - RESTORE can disable the MyISAM Key Cache Added FORCE INDEX to the tested statement. Removed old attempts to stabilize the test case. Added proper resetting of the debug variable to disturb debugging as little as possible. Removed clearing of the debug variable. @ mysys/mf_keycache.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Added cleanup for blocks_used and blocks_unused. Added DBUG. @ storage/myisam/myisamlog.c Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from mi_examine_log.c to here. original changeset: 2599.130.19 @ mysql-test/r/backup_myisam2.result WL#5101 - MySQL Backup back port - MS09 Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/r/myisam_keycache_coverage.result WL#5101 - MySQL Backup back port - MS09 Bug#44068 - RESTORE can disable the MyISAM Key Cache Updated test result. @ mysql-test/t/backup_myisam2.test WL#5101 - MySQL Backup back port - MS09 Bug#44068 - RESTORE can disable the MyISAM Key Cache Added checks for the state of the key cache. @ mysql-test/t/myisam_keycache_coverage.test WL#5101 - MySQL Backup back port - MS09 Bug#44068 - RESTORE can disable the MyISAM Key Cache Added FORCE INDEX to the tested statement. Removed old attempts to stabilize the test case. Added proper resetting of the debug variable to disturb debugging as little as possible. Removed clearing of the debug variable. @ storage/myisam/mi_examine_log.c WL#5101 - MySQL Backup back port - MS09 Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from here to myisamlog.c @ storage/myisam/myisamlog.c WL#5101 - MySQL Backup back port - MS09 Bug#44068 - RESTORE can disable the MyISAM Key Cache Moved calls to init_key_cache() and end_key_cache() from mi_examine_log.c to here.
Description: When restoring a MyISAM table with the native MyISAM restore driver, the MyISAM Key Cache can be turned off. How to repeat: Run the test backup_myisam_sync before the test myisam_keycache_coverage. The latter will fail with "". The reason is that the former implicitly disables the key cache, so that the error injection in the latter test does not take effect. Suggested fix: --- storage/myisam/mi_examine_log.c 2009-02-22 18:02:16 +0000 +++ storage/myisam/mi_examine_log.c 2009-04-02 19:13:31 +0000 @@ -175,6 +175,7 @@ int mi_examine_log(MI_EXAMINE_LOG_PARAM { { 11, 14 }, { 15, 22 }, { 15, 22 }, { 11, 14 }, { 11, 14 }, { 11, 14 }, { 11, 14 }, { 11, 14 }, { 9, 16 }, { 9, 16 }, { 7, 12 } }; uint has_pid_and_result[]= {1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0}; + int key_cache_blocks; DBUG_ENTER("mi_examine_log"); DBUG_PRINT("myisamlog", ("max_files: %u update: %u", mi_exl->max_files, mi_exl->update)); @@ -208,8 +209,13 @@ int mi_examine_log(MI_EXAMINE_LOG_PARAM bzero(mi_exl->com_count,sizeof(mi_exl->com_count)); init_tree(&tree,0,0,sizeof(file_info),(qsort_cmp2) file_info_compare,1, (tree_element_free) file_info_free, NULL); - (void) init_key_cache(dflt_key_cache,KEY_CACHE_BLOCK_SIZE,KEY_CACHE_SIZE, - 0, 0); + /* + init_key_cache() returns the number of cache blocks allocated, if + *this* call allocated them. If the function fails, or if the cache + was already initialized before, it returns zero. + */ + key_cache_blocks= init_key_cache(dflt_key_cache, KEY_CACHE_BLOCK_SIZE, + KEY_CACHE_SIZE, 0, 0); /* Initialize members of file_info that are used for pointing to @@ -778,7 +784,9 @@ int mi_examine_log(MI_EXAMINE_LOG_PARAM } DBUG_PRINT("myisamlog", ("end loop access_time: %lu cmd_cnt: %lu", access_time, mi_exl->number_of_commands)); - end_key_cache(dflt_key_cache,1); + /* End the key cache only if it was initialized by this function. */ + if (key_cache_blocks) + end_key_cache(dflt_key_cache,1); delete_tree(&tree); (void) end_io_cache(&cache); (void) my_close(log_file,MYF(0)); @@ -803,7 +811,9 @@ int mi_examine_log(MI_EXAMINE_LOG_PARAM fflush(stderr); end: DBUG_PRINT("myisamlog", ("end label")); - end_key_cache(dflt_key_cache, 1); + /* End the key cache only if it was initialized by this function. */ + if (key_cache_blocks) + end_key_cache(dflt_key_cache, 1); delete_tree(&tree); (void) end_io_cache(&cache); (void) my_close(log_file,MYF(0));