Description:
When the XA support functions are enabled by a storage engine and binlog is not enabled, MySQL crashes on startup or shutdown
startup:
(gdb) bt
#0 TC_LOG_MMAP::recover (this=0x1317920) at /home/xzy/mysql-5.6.26-src/sql/log.cc:2910
#1 0x000000000064fe88 in TC_LOG_MMAP::open (this=0x1317920, opt_name=<value optimized out>) at /home/xzy/mysql-5.6.26-src/sql/log.cc:2565
#2 0x000000000059c0c8 in init_server_components () at /home/xzy/mysql-5.6.26-src/sql/mysqld.cc:4962
#3 0x00000000005a0d75 in mysqld_main (argc=23, argv=0x13682a0) at /home/xzy/mysql-5.6.26-src/sql/mysqld.cc:5446
#4 0x0000003748e1ed5d in __libc_start_main () from /lib64/libc.so.6
#5 0x00000000005930b9 in _start ()
shutdown:
(gdb) bt
#0 0x0000000000652adb in TC_LOG_MMAP::log_xid (this=0x1317920, thd=<value optimized out>, xid=16) at /home/xzy/mysql-5.6.26-src/sql/log.cc:2744
#1 0x0000000000652fbb in TC_LOG_MMAP::commit (this=<value optimized out>, thd=0x4c213e0, all=true) at /home/xzy/mysql-5.6.26-src/sql/log.cc:2677
#2 0x00000000006acb4e in THD::cleanup (this=0x4c213e0) at /home/xzy/mysql-5.6.26-src/sql/sql_class.cc:1535
#3 0x00000000006acd48 in THD::release_resources (this=0x4c213e0) at /home/xzy/mysql-5.6.26-src/sql/sql_class.cc:1580
#4 0x00000000005994dc in one_thread_per_connection_end (thd=0x4c213e0, block_pthread=true) at /home/xzy/mysql-5.6.26-src/sql/mysqld.cc:2751
#5 0x00000000006af863 in do_handle_one_connection (thd_arg=<value optimized out>) at /home/xzy/mysql-5.6.26-src/sql/sql_connect.cc:989
#6 0x00000000006af957 in handle_one_connection (arg=<value optimized out>) at /home/xzy/mysql-5.6.26-src/sql/sql_connect.cc:898
#7 0x000000000090b3ea in pfs_spawn_thread (arg=0x4cdf1d0) at /home/xzy/mysql-5.6.26-src/storage/perfschema/pfs.cc:1860
#8 0x0000003749207a51 in start_thread () from /lib64/libpthread.so.0
#9 0x0000003748ee89ad in clone () from /lib64/libc.so.6
this bug is already reported as http://bugs.mysql.com/bug.php?id=47134
bug the fix is not correct.
How to repeat:
see also: http://bugs.mysql.com/bug.php?id=47134
or with my migerated spider engine https://github.com/xiezhenye/mysql-plugin-spider-engine
with
log_bin=off
spider_support_xa=on
spider_internal_xa=off
Suggested fix:
this bug seems fixed in 5.7 branch, but still exists in 5.6 branch
my patch:
*** log.cc.old 2015-08-13 12:29:56.266711505 +0800
--- log.cc 2015-08-13 14:14:59.468927153 +0800
*************** int TC_LOG_MMAP::open(const char *opt_na
*** 2553,2564 ****
mysql_mutex_init(key_PAGE_lock, &pg->lock, MY_MUTEX_INIT_FAST);
mysql_cond_init(key_PAGE_cond, &pg->cond, 0);
pg->start=(my_xid *)(data + i*tc_log_page_size);
! pg->end=(my_xid *)(pg->start + tc_log_page_size);
pg->size=pg->free=tc_log_page_size/sizeof(my_xid);
}
pages[0].size=pages[0].free=
(tc_log_page_size-TC_LOG_HEADER_SIZE)/sizeof(my_xid);
pages[0].start=pages[0].end-pages[0].size;
pages[npages-1].next=0;
inited=4;
--- 2553,2566 ----
mysql_mutex_init(key_PAGE_lock, &pg->lock, MY_MUTEX_INIT_FAST);
mysql_cond_init(key_PAGE_cond, &pg->cond, 0);
pg->start=(my_xid *)(data + i*tc_log_page_size);
! pg->ptr=pg->start;
pg->size=pg->free=tc_log_page_size/sizeof(my_xid);
+ pg->end=pg->start + pg->size;
}
pages[0].size=pages[0].free=
(tc_log_page_size-TC_LOG_HEADER_SIZE)/sizeof(my_xid);
pages[0].start=pages[0].end-pages[0].size;
+ pages[0].ptr=pages[0].start;
pages[npages-1].next=0;
inited=4;
*************** int TC_LOG_MMAP::sync()
*** 2815,2821 ****
/* marking 'syncing' slot free */
mysql_mutex_lock(&LOCK_sync);
syncing=0;
! mysql_cond_signal(&active->cond); // wake up a new syncer
mysql_mutex_unlock(&LOCK_sync);
return err;
}
--- 2817,2826 ----
/* marking 'syncing' slot free */
mysql_mutex_lock(&LOCK_sync);
syncing=0;
! if (active)
! {
! mysql_cond_signal(&active->cond); // wake up a new syncer
! }
mysql_mutex_unlock(&LOCK_sync);
return err;
}
