Bug #51557 | LOCK_open and kernel_mutex are not happy together | ||
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Submitted: | 26 Feb 2010 15:41 | Modified: | 8 Jul 2010 17:38 |
Reporter: | Mark Callaghan | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Locking | Severity: | S2 (Serious) |
Version: | 5.0.84 | OS: | Any |
Assigned to: | Konstantin Osipov | CPU Architecture: | Any |
Tags: | Contribution, handler, innodb, kernel_mutex, LOCK_open, open, performance, table |
[26 Feb 2010 15:41]
Mark Callaghan
[26 Feb 2010 15:42]
Mark Callaghan
See http://mituzas.lt/2010/02/26/opening-tables-v2 and http://mituzas.lt/2009/12/26/opening-tables/
[26 Feb 2010 18:14]
Domas Mituzas
Antony says: "There is an old patch (you can search for it on the bk commits list) which safely releases the LOCK_open mutex before calling the storage engines ::open method. The patch was primarily for fixing DOS scenerio when using the Federated storage engine but it would be equally applicable in this case." May be useful!
[26 Feb 2010 19:22]
Davi Arnaut
WL#3983
[27 Mar 2010 12:13]
Konstantin Osipov
http://lists.mysql.com/commits/103808
[27 Mar 2010 15:09]
Domas Mituzas
Kostja, can that behavior be merged into 5.1 too?
[27 Mar 2010 15:11]
Domas Mituzas
(I mean, is it safe, if we merge it ourselves? :)
[28 Mar 2010 8:49]
Konstantin Osipov
No it depends on the architecture changes done by the new MDL in 5.5. If you promise to never use DDL under LOCK TABLES (inc. REPAIR) it can work in 5.1, otherwise it'll crash.
[28 Mar 2010 8:51]
Konstantin Osipov
I was merely discussing the approach, the patch won't apply to 5.1.
[28 Mar 2010 9:01]
Domas Mituzas
ah, thanks.
[21 Apr 2010 0:36]
Jimmy Yang
I agree with Mark in this aspect. A more reasonable fix for 5.1 will be calling ha_innobase::info() with HA_STATUS_TIME, HA_STATUS_NO_LOCK, HA_STATUS_VARIABLE, HA_STATUS_CONST after the table opening and releasing of the LOCK_open lock. And we will avoid index stats collection and other info activity in ha_innobase::open itself.
[23 Apr 2010 20:46]
Mark Callaghan
This is probably a duplicate of http://bugs.mysql.com/bug.php?id=49463 I don't know why I reported it twice.
[23 Apr 2010 22:17]
Mark Callaghan
Patch for 5.1 at http://bazaar.launchpad.net/~mysqlatfacebook/mysqlatfacebook/5.1/revision/3470 We can contribute this. I don't know if it is relevant given the changes in 5.5
[15 Jun 2010 8:19]
Bugs System
Pushed into 5.5.5-m3 (revid:alik@sun.com-20100615080459-smuswd9ooeywcxuc) (version source revid:mmakela@bk-internal.mysql.com-20100415070122-1nxji8ym4mao13ao) (merge vers: 5.1.47) (pib:16)
[15 Jun 2010 8:36]
Bugs System
Pushed into mysql-next-mr (revid:alik@sun.com-20100615080558-cw01bzdqr1bdmmec) (version source revid:mmakela@bk-internal.mysql.com-20100415070122-1nxji8ym4mao13ao) (pib:16)
[15 Jun 2010 15:15]
Konstantin Osipov
Queued into 5.5.5 runtime, tagged 5.5.5 3054 Konstantin Osipov 2010-06-11 WL#5419 "LOCK_open scalability: make tdc_refresh_version an atomic counter" Split the large LOCK_open section in open_table(). Do not call open_table_from_share() under LOCK_open. Remove thd->version. This fixes Bug#50589 "Server hang on a query evaluated using a temporary table" Bug#51557 "LOCK_open and kernel_mutex are not happy together" Bug#49463 "LOCK_table and innodb are not nice when handler instances are created". This patch has effect on storage engines that rely on ha_open() PSEA method being called under LOCK_open. In particular: 1) NDB is broken and left unfixed. NDB relies on LOCK_open being kept as part of ha_open(), since it uses auto-discovery. While previously the NDB open code was race-prone, now it simply fails on asserts. 2) HEAP engine had a race in ha_heap::open() when a share for the same table could be added twice to the list of shares, or a dangling reference to a share stored in HEAP handler. This patch aims to address this problem by 'pinning' the newly created share in the internal HEAP engine share list until at least one handler instance is created using that share. @ include/heap.h Add members to HP_CREATE_INFO. Declare heap_release_share(). @ sql/lock.cc Remove thd->version, use thd->open_tables->s->version instead. @ sql/repl_failsafe.cc Remove thd->version. @ sql/sql_base.cc - close_thread_table(): move handler cleanup code outside the critical section protected by LOCK_open. - remove thd->version - split the large critical section in open_table() that opens a new table from share and is protected by LOCK_open into 2 critical sections, thus reducing the critical path. - make check_if_table_exists() acquire LOCK_open internally. - use thd->open_tables->s->version instead of thd->refresh_version to make sure that all tables in thd->open_tables are in the same refresh series. @ sql/sql_base.h Add declaration for check_if_table_exists(). @ sql/sql_class.cc Remove init_open_tables_state(), it's now equal to reset_open_tables_state(). @ sql/sql_class.h Remove thd->version, THD::init_open_tables_state(). @ sql/sql_plugin.cc Use table->m_needs_reopen to mark the table as stale rather than manipulate with thd->version, which is no more. @ sql/sql_udf.cc Use table->m_needs_reopen to mark the table as stale rather than manipulate with thd->version, which is no more. @ sql/table.h Remove an unused variable. @ sql/tztime.cc Use table->m_needs_reopen to mark the table as stale rather than manipulate with thd->version, which is no more. @ storage/heap/CMakeLists.txt Add heap tests to cmake build files. @ storage/heap/ha_heap.cc Fix a race when ha_heap::ha_open() could insert two HP_SHARE objects into the internal share list or store a dangling reference to a share in ha_heap instance, or wrongly set implicit_emptied. @ storage/heap/hp_create.c Optionally pin a newly created share in the list of shares by increasing its open_count. This is necessary to make sure that a newly created share doesn't disappear while a HP_INFO object is being created to reference it. @ storage/heap/hp_open.c When adding a new HP_INFO object to the list of objects in the heap share, make sure the open_count is not increased twice. @ storage/heap/hp_test1.c Adjust the test to new function signatures. @ storage/heap/hp_test2.c Adjust the test to new function signatures.
[22 Jun 2010 13:08]
Bugs System
Pushed into 5.5.5-m3 (revid:alik@sun.com-20100622130139-u05awgya93zvbsop) (version source revid:marko.makela@oracle.com-20100603095032-v5ptkkzt1bhz0m1d) (merge vers: 5.1.48) (pib:16)
[22 Jun 2010 13:10]
Bugs System
Pushed into mysql-next-mr (revid:alik@sun.com-20100622130623-r7yhm89fz9n5t9nb) (version source revid:alik@sun.com-20100622130528-187gd949sa9b6pa6) (pib:16)
[8 Jul 2010 16:11]
Paul DuBois
Noted in 5.5.5 changelog. Previously, the server held a global mutex while performing file operations such as deleting an .frm or data file, or reading table metadata from an .frm file or index statistics from a data file. Now the mutex is not held for these operations. Instead, the server uses metadata locks.
[8 Jul 2010 17:38]
Mark Callaghan
=D> The applause emoticon according to http://www.muller-godschalk.com/yahoo.html
[13 May 2011 13:31]
Paul DuBois
Correction to changelog entry: Remove "reading table metadata from an .frm file"