database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-08 11:22:35 +03:00
Code Activity

MDEV-9510 Segmentation fault in binlog thread causes crash

Browse Source 
With combination of --log-bin and Galera the server may crash
reporting two characteristic stacks:

  /usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG13mark_xid_doneEmb+0xc7)[0x7f182a8e2cb7]
  /usr/sbin/mysqld(binlog_background_thread+0x2b5)[0x7f182a8e3275]

or

  /usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG21do_checkpoint_requestEm+0x9d)[0x7ff395b2dafd]
  /usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG20checkpoint_and_purgeEm+0x11)[0x7ff395b2db91]
  /usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG16rotate_and_purgeEb+0xc2)[0x7ff395b300b2]

The reason of the failure appears to be non-matching decrements for
  `xid_count_per_binlog::xid_count`
which can occur when a transaction is executed having its connection issued
`SET @@sql_log_bin=0`. In such case the xid count is not incremented but
its decrements still runs to turn `binlog_xid_count_list` into improper state
which the following FLUSH BINARY LOGS exposes through the crash.

*Note_1*: the regression test reuses an existing galera.sql_log_bin
which does not run stably (even in its base form) by mtr with --log-bin.

*Note_2*: 10.0-galera branch is free of this issue having missed MDEV-7205
fixes.
This commit is contained in:
Andrei Elkin
2017-10-16 19:32:02 +03:00
parent aae4932775
commit c7e38076f3
3 changed files with 33 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
mysql-test/suite/galera/r/sql_log_bin.result
View File

@@ -6,6 +6,7 @@ INSERT INTO t1 VALUES (1);
# Disable binary logging for current session
SET SQL_LOG_BIN=OFF;
INSERT INTO t1 VALUES (2);
FLUSH BINARY LOGS;
CREATE TABLE t2(c1 INT PRIMARY KEY) ENGINE=INNODB;
INSERT INTO t2 VALUES (1);
CREATE TABLE test.t3 AS SELECT * from t1;