损坏的InnoDB表、mysqlcheck和mysqldump崩溃服务器

Question

我管理一个Percona XtraDB集群，它使用一个带有抖动连接的网络存储。周期性地，我们经历了一个高iowait与崩溃和重新装入的fs在只读。不幸的是，目前还不能选择替换存储空间。

最近，我注意到当运行mysqldump或mysqlcheck时，它们会导致节点上的MySQL服务器崩溃，并产生错误mysqlcheck: Got error: 2013: Lost connection to MySQL server during query when executing 'CHECK TABLE ... '。

以下是崩溃期间mysqld.log的内容：

InnoDB: Error in pages 9479 and 9480 of index "PRIMARY" of table "foobar"."quux"
InnoDB: broken FIL_PAGE_NEXT or FIL_PAGE_PREV links
2015-09-28 14:39:45 7f015813b700 InnoDB: Page dump in ascii and hex (16384 bytes):

(...)

InnoDB: End of page dump
2015-09-28 14:39:45 7f015813b700 InnoDB: uncompressed page, stored checksum in field1 4038097986, calculated checksums for field1: crc32 2787032309, innodb 4038097986, none 3735928559, stored checksum in field2 1190336748, calculated checksums for field2: crc32 2787032309, innodb 1190336748, none 3735928559, page LSN 4 3652646491, low 4 bytes of LSN at page end 3652646491, page number (if stored to page already) 9479, space id (if created with >= MySQL-4.1.1 and stored already) 18
InnoDB: Page may be an index page where index id is 67
InnoDB: (index "PRIMARY" of table "foobar"."quux")
2015-09-28 14:39:45 7f015813b700 InnoDB: Page dump in ascii and hex (16384 bytes):

(...) 

InnoDB: End of page dump
2015-09-28 14:39:46 7f015813b700 InnoDB: uncompressed page, stored checksum in field1 554678569, calculated checksums for field1: crc32 2178598661, innodb 554678569, none 3735928559, stored checksum in field2 1065260512, calculated checksums for field2: crc32 2178598661, innodb 1065260512, none 3735928559, page LSN 10 202985777, low 4 bytes of LSN at page end 202985777, page number (if stored to page already) 6792, space id (if created with >= MySQL-4.1.1 and stored already) 18
InnoDB: Page may be an index page where index id is 67
InnoDB: (index "PRIMARY" of table "foobar"."quux")
InnoDB: Corruption of an index tree: table "foobar"."quux", index "PRIMARY",
InnoDB: father ptr page no 55234, child page no 9479
PHYSICAL RECORD: n_fields 14; compact format; info bits 0
 0: len 30; hex 34616434393538322d353232372d653863302d326466662d353461663639; asc 4ad49582-5227-e8c0-2dff-54af69; (total 36 bytes);
 1: len 6; hex 000000000dd7; asc       ;;
 2: len 7; hex c8000001741ea1; asc     t  ;;
 3: len 5; hex 99951259cb; asc    Y ;;
 4: len 5; hex 99951259cb; asc    Y ;;
 5: len 30; hex 62633965323864352d383865382d343466322d393337322d353339303931; asc bc9e28d5-88e8-44f2-9372-539091; (total 36 bytes);
 6: len 30; hex 62633965323864352d383865382d343466322d393337322d353339303931; asc bc9e28d5-88e8-44f2-9372-539091; (total 36 bytes);
 7: len 1; hex 80; asc  ;;
 8: len 30; hex 64356664666538352d656431652d346465362d383363612d616439663164; asc d5fdfe85-ed1e-4de6-83ca-ad9f1d; (total 36 bytes);
 9: len 8; hex 436f6e7461637473; asc Contacts;;
 10: len 4; hex 6c696e6b; asc link;;
 11: len 30; hex 7b226f626a656374223a7b226e616d65223a224d72204a6f7264616e204e; asc {"object":{"name":"Mr John Hacker; (total 343 bytes);
 12: len 4; hex 80000000; asc     ;;
 13: len 30; hex 7b226e616d65223a22222c22646f635f6f776e6572223a22222c22757365; asc {"name":"","doc_owner":"","use; (total 72 bytes);
 n_owned: 0; heap_no: 2; next rec: 751
PHYSICAL RECORD: n_fields 2; compact format; info bits 0
 0: len 30; hex 34616435616262302d303535662d333939612d613038652d353439396461; asc 4ad5abb0-055f-399a-a08e-5499da; (total 36 bytes);
 1: len 4; hex 0000d7c2; asc     ;;
 n_owned: 0; heap_no: 277; next rec: 4688
InnoDB: You should dump + drop + reimport the table to fix the
InnoDB: corruption. If the crash happens at the database startup, see
InnoDB: http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html about
InnoDB: forcing recovery. Then dump + drop + reimport.
2015-09-28 14:39:46 7f015813b700  InnoDB: Assertion failure in thread 139643749381888 in file btr0btr.cc line 1492
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/5.6/en/forcing-innodb-recovery.html
InnoDB: about forcing recovery.
12:39:46 UTC - 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.
Please help us make Percona XtraDB Cluster better by reporting any
bugs at https://bugs.launchpad.net/percona-xtradb-cluster

key_buffer_size=25165824
read_buffer_size=131072
max_used_connections=7
max_threads=202
thread_count=10
connection_count=5
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 105204 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0xf4de780
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 = 7f015813ad38 thread_stack 0x40000
/usr/sbin/mysqld(my_print_stacktrace+0x35)[0x8fa965]
/usr/sbin/mysqld(handle_fatal_signal+0x4b4)[0x665644]
/lib64/libpthread.so.0(+0xf710)[0x7f0185a25710]
/lib64/libc.so.6(gsignal+0x35)[0x7f0183e6b625]
/lib64/libc.so.6(abort+0x175)[0x7f0183e6ce05]
/usr/sbin/mysqld[0xa10d84]
/usr/sbin/mysqld[0xa16cc8]
/usr/sbin/mysqld[0x917920]
/usr/sbin/mysqld(_ZN7handler8ha_checkEP3THDP15st_ha_check_opt+0x6a)[0x5a422a]
/usr/sbin/mysqld[0x835fc3]
/usr/sbin/mysqld(_ZN19Sql_cmd_check_table7executeEP3THD+0xc2)[0x836cd2]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x33d5)[0x6ed235]
/usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x658)[0x6f0958]
/usr/sbin/mysqld[0x6f0acd]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x19d5)[0x6f2de5]
/usr/sbin/mysqld(_Z10do_commandP3THD+0x22b)[0x6f42cb]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x17f)[0x6bc52f]
/usr/sbin/mysqld(handle_one_connection+0x47)[0x6bc717]
/usr/sbin/mysqld(pfs_spawn_thread+0x12a)[0xaf611a]
/lib64/libpthread.so.0(+0x79d1)[0x7f0185a1d9d1]
/lib64/libc.so.6(clone+0x6d)[0x7f0183f218fd]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (7efebc091d30): is an invalid pointer
Connection ID (thread ID): 2336
Status: NOT_KILLED

很明显，这张桌子的foobar.quux损坏严重。使用数据库的应用程序仍然工作(尽管性能下降)，SELECT语句也是如此。

mysqlcheck工具无法用于修复它，所以我所知道的解决方案是在下一个维护窗口中执行SELECT * FROM quux INTO OUTFILE、删除表和执行LOAD DATA INFILE。这种方式是否有缺点，还有其他方法来修复表吗？

编辑:我重新启动了MySQL服务器，将innodb_force_recovery值从1增加到4，结果总是一样的：

• mysqldump出现错误mysqldump: Error 2013: Lost connection to MySQL server during query when dumping table quux at row: 156915失败。
• MySQL命令SELECT * FROM quux INTO OUTFILE '/root/quux.sql';在错误ERROR 2013 (HY000): Lost connection to MySQL server during query后不久就失败了。

我要试试innodb_force_recovery=5和innodb_force_recovery=6吗？缺点是什么？

Answer 1

mysqlcheck不会修复InnoDB表中的损坏。您需要从表中转储数据并重新创建它。

使用MySQL选项启动innodb_force_recovery。尝试从1到6的值，直到MySQL启动。

用mysqldump转储表。

把桌子放下。

重新启动MySQL w/o innodb_force_recovery。

重新装填垃圾堆。

Answer 2

就其价值而言，我发现mysqlcheck -o可以有效地修复损坏的InnoDB表，因为它实际上进行了“重新创建+分析”。我有一个损坏的表，它阻止mysql启动。首先我试过：

mysqlcheck -r db_name table_name

返回：

db_name.table_name注意:表的存储引擎不支持修复

然后我试着：

mysqlcheck -o db_name table_name

还有..。

db_name.table_name注意:表不支持优化，而是重新创建+分析状态: OK

不确定这能弥补每一种腐败，但它对我有效。

Answer 3

我一直在处理无伤大雅的腐败。

我想在转储和重新输入数据库之前，我应该尝试几件事。

所有的检查数据库对我都不起作用，但这确实有效。

我使用了下面的命令，没有指定表名。

我相信这会检查/修复数据库中的每个表，这可能会非常冗长，取决于您的表数，但是总体上是这样的，所有的事情都已经恢复和运行了。

mysqlcheck -o db_name 

注意:登录到mysql并运行显示数据库；

要获取数据库列表，然后在上面的命令中插入名称，然后让它运行几个。

我和nextcloud有问题，它帮我解决了问题。