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Bug#17327454:SEMI-SYNC REPLICATION MASTER CRASH WHEN SET

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RPL_SEMI_SYNC_MASTER_ENABLED OFF.

Problem:
=======
If master is waiting for a reply from slave, at this time
set global rpl_semi_sync_master_enabled=OFF, the master
server will crash.

Analysis:
========
When master is waiting for a reply from slave, at this time
if semi sync is switched off on master, during switch off if
active transactions are present the transactions will be
cleared and "active_tranxs_" variable will be set to NULL.

When the waiting master connection finds that semi sync is
switched of it tries to access "active_tranxs_" without
checking if the transaction list exists or not. Accessing
NULL transaction list causes the crash.

Fix:
===
A check has been added to see a valid list exists before
accessing the "active_tranxs_".
This commit is contained in:
Sujatha Sivakumar
2013-09-23 12:13:37 +05:30
parent d0941fbc4c
commit 5a5024a6bd
1 changed files with 2 additions and 1 deletions
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3
plugin/semisync/semisync_master.cc
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@ -752,7 +752,8 @@ int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
At this point, the binlog file and position of this transaction At this point, the binlog file and position of this transaction
must have been removed from ActiveTranx. must have been removed from ActiveTranx.
*/ */
assert(!active_tranxs_->is_tranx_end_pos(trx_wait_binlog_name, assert(!getMasterEnabled() ||
!active_tranxs_->is_tranx_end_pos(trx_wait_binlog_name,
trx_wait_binlog_pos)); trx_wait_binlog_pos));
/* Update the status counter. */ /* Update the status counter. */