key_buffer_size=335544320
read_buffer_size=1048576
max_used_connections=149
max_threads=4000
threads_connected=43
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 8560336 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd: 0x2aac7c25b990
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 = 0x46ba6f20 thread_stack 0x40000

100721 11:01:42 mysqld_safe Number of processes running now: 0
100721 11:01:42 mysqld_safe mysqld restarted
InnoDB: Log scan progressed past the checkpoint lsn 63 1559628325
100721 11:01:43 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 63 1564041997
100721 11:01:44 InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 0 1 2 3 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 3
7 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 8
1 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed
InnoDB: Last MySQL binlog file position 0 906880987, file name /home/mysql/data/mysql/mysql-bin.000458
100721 11:01:54 InnoDB: Started; log sequence number 63 1564041997
100721 11:01:54 [Note] Recovering after a crash using /home/mysql/data/mysql/mysql-bin
100721 11:01:56 [Note] Starting crash recovery...
100721 11:01:56 [Note] Crash recovery finished.
100721 11:01:57 [Note] Slave SQL thread initialized, starting replication in log 'mysql-bin.000456' at position 409173074, relay log
'/home/mysql/data/mysql/slave-relay.001030' position: 251
100721 11:01:57 [Note] Slave I/O thread: connected to master 'replicator@10.247.63.2:3306',replication started in log 'mysql-bin.000
456' at position 409173074
100721 11:01:57 [Note] Event Scheduler: Loaded 0 events
100721 11:01:57 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.1.40-community-log' socket: '/tmp/mysql.sock' port: 3306 MySQL Community Server (GPL)

/VAR/LOG/MESSAGES 日志如下：
Jul 21 11:01:42 r21c05033 kernel: mysqld[29543]: segfault at 0000000000000038 rip 000000000077d825 rsp 0000000041fd5fa0 error 4

SLAVE MYSQL 日志报错如下：

100721 11:01:42 [ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)
100721 11:01:42 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.000458' at postion 906880987
100721 11:01:42 [ERROR] Slave I/O: error reconnecting to master 'replicator@10.247.63.1:3306' - retry-time: 60 retries: 86400, Error_code: 2013
100721 11:02:42 [Note] Slave: connected to master 'replicator@10.247.63.1:3306',replication resumed in log 'mysql-bin.000458' at position 906880987

网上很多朋友也碰到了类似的错误，但MS都没有找到原因。只知道BUG. 有没有朋友碰到过，一起分析下状况？

root@r21c05033.btc.aliyun.com # free
total used free shared buffers cached
Mem: 24677088 18645608 6031480 0 447856 16351076
-/+ buffers/cache: 1846676 22830412
Swap: 2096440 228 2096212

# /etc/my.cnf
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 8M
join_buffer_size = 16M
key_buffer_size = 320M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
innodb_additional_mem_pool_size = 300M
innodb_buffer_pool_size = 6G
innodb_log_buffer_size = 4M
innodb_file_per_table
innodb_doublewrite=1