| Bug #41634 | Agent seems to fail to reconnect to database (and web ui events shown unclearly) | ||
|---|---|---|---|
| Submitted: | 19 Dec 2008 12:10 | Modified: | 6 Mar 2009 20:10 |
| Reporter: | Simon Mudd (OCA) | Email Updates: | |
| Status: | Duplicate | Impact on me: | |
| Category: | MySQL Enterprise Monitor: Agent | Severity: | S3 (Non-critical) |
| Version: | 2.0.0.7111 | OS: | Linux (CentOS 4 x86_64) |
| Assigned to: | CPU Architecture: | Any | |
[19 Dec 2008 12:10]
Simon Mudd
[19 Dec 2008 12:19]
Simon Mudd
change Synopsis to be more precise
[19 Dec 2008 12:47]
Simon Mudd
Same issue with another server. Same symptoms. Server rebooted for new memory to be added. # uptime 13:38:37 up 1 day, 33 min, 1 user, load average: 0.14, 0.04, 0.01 # mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 53904 Server version: 5.0.68-enterprise-gpl-log MySQL Enterprise Server (GPL) Type 'help;' or '\h' for help. Type '\c' to clear the buffer. root@master [(none)]> show status like 'uptime'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Uptime | 88388 | +---------------+-------+ 1 row in set (0.00 sec) root@master [(none)]> exit Bye # tail /opt/mysql/enterprise/agent/mysql-monitor-agent.log 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 86125' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 86126' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 88662' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 88700' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 89910' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 89912' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-17 15:49:43: (critical) network-io.c:843: response to 'command: collect_data, task-id: 89913' has was for old session-id: 1229447376672.143, current session-id: 1229525379213.93. Trashing it. 2008-12-18 12:00:00: (critical) agent_mysqld.c:600: agent connecting to mysql-server failed: mysql_real_connect(host = '127.0.0.1', port = 3306, socket = ''): Can't connect to MySQL server on '127.0.0.1' (111) (mysql-errno = 2003) 2008-12-18 12:39:01: (critical) agent_mysqld.c:600: agent connecting to mysql-server failed: mysql_real_connect(host = '127.0.0.1', port = 3306, socket = ''): Can't connect to MySQL server on '127.0.0.1' (111) (mysql-errno = 2003) 2008-12-18 13:05:25: (critical) agent_mysqld.c:600: agent connecting to mysql-server failed: mysql_real_connect(host = '127.0.0.1', port = 3306, socket = ''): Can't connect to MySQL server on '127.0.0.1' (111) (mysql-errno = 2003) The agent IS running. # /opt/mysql/enterprise/agent/etc/init.d/mysql-monitor-agent start Starting MySQL Enterprise agent service...(already running)[ OK ]
[22 Dec 2008 16:54]
Diego Medina
Hi Simon, Thanks for your bug report. Looking at your log, I see that you get the error about not being able to connect to the mysql server a few times, but the agent actually tries to reconnect to the mysql server once every minute if there is a problem. What I think happened in your case is that there were "some" connectivity problems, but the agent recovered. I say this because on the last log you posted, you get the error more or less every 30 minutes. I tried reproducing the bug but once I restarted the mysql server, the agent was able to connect to it. You have a valid point when asking for more event entries. I will file a separate feature request for it. Thank you.
[22 Dec 2008 19:41]
Diego Medina
See http://bugs.mysql.com/bug.php?id=41679 for the feature request
[23 Jan 2009 0:00]
Bugs System
No feedback was provided for this bug for over a month, so it is being suspended automatically. If you are able to provide the information that was originally requested, please do so and change the status of the bug back to "Open".
[23 Jan 2009 7:43]
Simon Mudd
You close this ticket saying it is a duplicate of 41679 which I wrote afterwards. If so please close the ticket and link the 2 bugs together. The agent failing to notify of a correct reconnection to the database is still a problem in 2.0.2.7133 IIRC so the bug and the feature request are 2 different things. Therefore I'm not sure it's appropriate to close this ticket.
[6 Feb 2009 7:55]
Simon Mudd
After recent upgrade to server 2.0.4.7138 and agent 2.0.4.7139 we still have the same issue. This is mainly manifested after a host/server restart. - the agent comes up before the mysqld server, so the mysql instance is NOT running - the mysqld comes up and works fine. - the agent does not realise (does not try again to check?) that the server is up and running. - hence reporting shown on the merlin server indicates that the mysql instance is not running when it is. This bug is shown as non-critical, but for successful monitoring it is critical as it provides misleading "mysql down" indications to the users of merlin. It thus wastes our time, and may lead us to ignore a real warning of the same type. Therefore please consider increasing the severity of this bug.
[18 Feb 2009 18:54]
Diego Medina
This is related to http://bugs.mysql.com/bug.php?id=42581
