Our production mysql server just crashed and won't come back up. It's giving a segfault error. I tried a reboot, and just don't know what else to try. Here is the stacktrace:
140502 14:13:05 [Note] Plugin 'FEDERATED' is disabled. InnoDB: Log scan progressed past the checkpoint lsn 108 1057948207 140502 14:13:06 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... InnoDB: Doing recovery: scanned up to log sequence number 108 1058059648 InnoDB: 1 transaction(s) which must be rolled back or cleaned up InnoDB: in total 15 row operations to undo InnoDB: Trx id counter is 0 562485504 140502 14:13:06 InnoDB: Starting an apply batch of log records to the database... InnoDB: Progress in percents: 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 InnoDB: Apply batch completed InnoDB: Starting in background the rollback of uncommitted transactions 140502 14:13:06 InnoDB: Rolling back trx with id 0 562485192, 15 rows to undo 140502 14:13:06 InnoDB: Started; log sequence number 108 1058059648 140502 14:13:06 InnoDB: Assertion failure in thread 1873206128 in file ../../../storage/innobase/fsp/fsp0fsp.c line 1593 InnoDB: Failing assertion: frag_n_used > 0 InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to http://bugs.mysql.com. InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.1/en/forcing-recovery.html InnoDB: about forcing recovery. 140502 14:13:06 - mysqld got signal 6 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=16777216 read_buffer_size=131072 max_used_connections=0 max_threads=151 threads_connected=0 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 345919 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. thd: 0x0 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = (nil) thread_stack 0x30000 140502 14:13:06 [Note] Event Scheduler: Loaded 0 events 140502 14:13:06 [Note] /usr/sbin/mysqld: ready for connections. Version: '5.1.41-3ubuntu12.10' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu) /usr/sbin/mysqld(my_print_stacktrace+0x2d) [0xb7579cbd] /usr/sbin/mysqld(handle_segfault+0x494) [0xb7245854] [0xb6fc0400] /lib/tls/i686/cmov/libc.so.6(abort+0x182) [0xb6cc5a82] /usr/sbin/mysqld(+0x4867e9) [0xb74647e9] /usr/sbin/mysqld(btr_page_free_low+0x122) [0xb74f1622] /usr/sbin/mysqld(btr_compress+0x684) [0xb74f4ca4] /usr/sbin/mysqld(btr_cur_compress_if_useful+0xe7) [0xb74284e7] /usr/sbin/mysqld(btr_cur_pessimistic_delete+0x332) [0xb7429e72] /usr/sbin/mysqld(btr_node_ptr_delete+0x82) [0xb74f4012] /usr/sbin/mysqld(btr_discard_page+0x175) [0xb74f41e5] /usr/sbin/mysqld(btr_cur_pessimistic_delete+0x3e8) [0xb7429f28] /usr/sbin/mysqld(+0x526197) [0xb7504197] /usr/sbin/mysqld(row_undo_ins+0x1b1) [0xb7504771] /usr/sbin/mysqld(row_undo_step+0x25f) [0xb74c210f] /usr/sbin/mysqld(que_run_threads+0x58a) [0xb74a31da] /usr/sbin/mysqld(trx_rollback_or_clean_all_without_sess+0x3e3) [0xb74ded43] /lib/tls/i686/cmov/libpthread.so.0(+0x596e) [0xb6f9f96e] /lib/tls/i686/cmov/libc.so.6(clone+0x5e) [0xb6d65a4e] The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash.
Check the suggested webpage: http://dev.mysql.com/doc/refman/5.1/en/forcing-recovery.html.
Basically, try to start the MySQL server in a recovery mode and make a backup of your crashed tables.
...to see if you can get into your database and get your data / find the corrupted table.
Usually, when this happens it's a re-build (at least of a corrupted table or two).
service mysql stop).
Add the following line into
(they suggest 4, but its best to start with 1 and increment if it won't start)
service mysql start).
mysqldump -A > dump.sql
service mysql stop).
mysqld. Look at mysql error log. By default it should be
/var/lib/mysql/server/hostname.com.errto see how it creates new
mysql < dump.sql