MySQL Bugs: #67876: mysqlbackup generates aborted connection warning

Bug #67876	mysqlbackup generates aborted connection warning
Submitted:	11 Dec 2012 17:04	Modified:	5 Mar 2013 12:36
Reporter:	Simon Cheng	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Enterprise Backup	Severity:	S3 (Non-critical)
Version:	3.9	OS:	Linux
Assigned to:		CPU Architecture:	Any
Tags:	mysqlbackup generates aborted connection warning

Description:
with connection warnings enabled (log_warning=2), mysqlbackup will cause an aborted connection warning to be logged to mysqld.log

expected behaviour would be for the mysqlbackup tool to run without generating any warnings. 

How to repeat:
set log_warning=2, run mysqlbackup in any flavor, observe aborted connection warning in mysqld log

Suggested fix:
mysqlbackup should close and cleanup connection properly so warning is not logged

Thank you for the report.

Verified as described.

To repeat:

1. In any MySQL build or source tree:

./mtr --start --mysqld=--log-warnings=2 innodb &

2. Create single InnoDB table with single row, so we are sure backup will be fast.

3. Run mysqlbackup --user=root --host=127.0.0.1 --port=13000 --backup-dir=YOUR_DIR backup

4. $ tail var/log/mysqld.1.err 
121213  3:07:10 InnoDB: 1.1.8 started; log sequence number 1595675
121213  3:07:10 [Warning] /home/sveta/src/mysql-5.5/sql/mysqld: unknown variable 'loose-debug-sync-timeout=300'
121213  3:07:10 [Note] Server hostname (bind-address): '0.0.0.0'; port: 13000
121213  3:07:10 [Note]   - '0.0.0.0' resolves to '0.0.0.0';
121213  3:07:10 [Note] Server socket created on IP: '0.0.0.0'.
121213  3:07:10 [Note] Event Scheduler: Loaded 0 events
121213  3:07:10 [Note] /home/sveta/src/mysql-5.5/sql/mysqld: ready for connections.
Version: '5.5.30-log'  socket: '/home/sveta/src/mysql-5.5/mysql-test/var/tmp/mysqld.1.sock'  port: 13000  MySQL Community Server (GPL)
121213  3:07:18 [Warning] Aborted connection 1 to db: 'mysql' user: 'root' host: 'localhost' (Got an error reading communication packets)
121213  4:04:12 [Warning] Aborted connection 2 to db: 'mysql' user: 'root' host: 'localhost' (Got an error reading communication packets)

Backup team is working on this

Bug fixed in MEB3.9

Added to changelog for 3.9.0: 

Doing a backup with the mysqlbackup command could cause an aborted
connection warning to appear in the MySQL error log when connection
warnings were enabled (with the setting log_warning=2 on the server).
The database connection was not closed correctly after the backup
completed.