Alan Bell sees correlation with the previous fork of Joomla from Mambo and has illustrated the potential impact that forking a project can have with a Google Trends chart, where Mambo is the blue line, and Joomla is the red line:

A similar chart for Debian (blue) and Ubuntu (red) is also instructive:

Or what about Nagios (blue) and Icinga (red):

Hmm. Maybe not the best example. After all, as we reported, the Icinga fork had some commercial motivations attached to it, and it’s not exactly the highest profile fork.

What about something a bit more comparable, like MySQL (blue) and MariaDB (red):

Oh.

Which is not to say that LibreOffice will not be a success, but when it comes to forking, creating the fork is clearly just the start. It takes time, and a lot of effort, to generate the momentum for a fork to be truly successful. There is bound to be an initial spike in developer and user interest. Turning that into a meaningful and productive community will be the hard part.

The server I was looking at runs some large local batch jobs aggregating data. Unfortunately, I was experiencing that replication was interfering with these batch jobs so decided to see if things would perform better if I stopped replication and let the batch jobs complete, restarting replication afterwards.

So the command STOP SLAVE was sent to the server, and this took some time. In the meantime SHOW SLAVE STATUS hangs. The STOP SLAVE command waits for the SQL replication thread to finish it’s task but that thread was waiting on the tables being used by the batch process, which was already running. The consequence of this was that STOP SLAVE waited, all calls to SHOW SLAVE STATUS blocked and with nagios, cacti, merlin and the local scripts all doing periodic SHOW SLAVE STATUS commands which would hang I ended up with the mysqld running out of user connections.  Nasty!

While I see if MySQL can do something about the behaviour of stopping the slave and showing the slave status I’m going to implement grants which limit the monitor users so they are only allowed to have a user concurrent connections open.  This is done using the syntax

GRANT whatever ON whereever TO some_user WITH MAX_USER_CONNECTIONS 5;

5 looks like a good number for nagios, merlin and the local scripts and 10 is probably sufficient as I collect a lot of graph data for the mysql server and the cacti requests are often done in parallel.

So if you monitor MySQL it may be worth you applying some sort of connection limit on your monitoring scripts, if not on other database users.

The server I was looking at runs some large local batch jobs aggregating data. Unfortunately, I was experiencing that replication was interfering with these batch jobs so decided to see if things would perform better if I stopped replication and let the batch jobs complete, restarting replication afterwards.

So the command STOP SLAVE was sent to the server, and this took some time. In the meantime SHOW SLAVE STATUS hangs. The STOP SLAVE command waits for the SQL replication thread to finish it’s task but that thread was waiting on the tables being used by the batch process, which was already running. The consequence of this was that STOP SLAVE waited, all calls to SHOW SLAVE STATUS blocked and with nagios, cacti, merlin and the local scripts all doing periodic SHOW SLAVE STATUS commands which would hang I ended up with the mysqld running out of user connections.  Nasty!

While I see if MySQL can do something about the behaviour of stopping the slave and showing the slave status I’m going to implement grants which limit the monitor users so they are only allowed to have a user concurrent connections open.  This is done using the syntax

GRANT whatever ON whereever TO some_user WITH MAX_USER_CONNECTIONS 5;

5 looks like a good number for nagios, merlin and the local scripts and 10 is probably sufficient as I collect a lot of graph data for the mysql server and the cacti requests are often done in parallel.

So if you monitor MySQL it may be worth you applying some sort of connection limit on your monitoring scripts, if not on other database users.

This worked fine, but recently I lost my IPv6 connectivity but thought no more about it. I’m trying to get it working again but that’s not happened yet.

Over the last few days I’ve had some intermittent issues logging in to my home pc from my laptop and I couldn’t figure out why. Eventually I had a look at the DNS requests and of course some requests were being made to my non-reachable name server. This generated some network delays while the resolver timed out and then tried talking to one of the IPv4 name servers and correctly retrieving the information.

So conclusion, if you setup yourself with a name server for your domain and include access on IPv6 then ensure that you monitor it. I do run nagios at home and intend to add some extra checks so that I can see if there are problems. Even when playing with IPv6 if you don’t have things setup properly it can affect non-IPv6 activity…

Once the unreachable IPv6 AAAA entry was removed from my name server things went back to normal.

When acquired by SpringSource a year ago, there was some question as to the real value of open source systems monitoring and management company Hyperic, which had taken the most pronounced and aggressive move toward the cloud. Flash forward to VMware’s latest SpringSource tc Server release and we see VMware, at the very least, still sees technical and market value in Hyperic, which continues to be its cloud appliation and infrastructure monitoring technology and brand. Hyperic and its acquisition by SpringSource also served as an early milestone in the devops trend.

As for GroundWork Open Source, the company just made an announcement for monitoring private clouds created with Eucalyptus Systems, which continues to gain buzz and attention itself with its recent hiring of former MySQL CEO Marten Mickos. The GroundWork-Eucalyptus joint offering, intended to provide one point of control for datacenters and cloud computing environments both private and public, is also intended for channel partners (which represent about half of GroundWork’s revenue) to offer Eucalyptus-based private clouds with monitoring as well.

Zenoss is another vendor that continues to leverage open source for systems management that is finding continued interest and traction in large part thanks to emergent models and strategies in cloud computing. In its case, Zenoss announced it will provide service assurance monitoring for private and public clouds based on Cisco’s Unified Computing System. The beta service promises enterprises and service providers fast and cost effective deployment of a unified operations console for UCS services, which could include physical, virtual and/or cloud computing environments.

There are also others that are still growing in the enterprise systems monitoring and management space with open source software: Nagios Enterprises and OpenNMS Group in particular. Nagios Enterprises, which shares the same name as the popular open source monitoring project, continues to grow its enterprise and cloud presence despite a fork and check on its development last year.

OpenNMS Group, among the most community and project-oriented of the open source commercial plays in systems management, is part of an interesting effort toward a cloud service broker (CSB), aimed at enabling service providers to connect to various cloud providers, along with British Telecom and others.

Given much of the efficiency and rewards of cloud computing center on driving greater utilization and efficiency, it is not surprising that monitoring is a big part of it. Given the trend toward using open source pieces for cloud computing, particularly as we consider the current wave of investment and building of private cloud infrastructures where open source is very well-suited, it is not surprising to see open source a big part of it, too.

http://code.google.com/p/check-mysql-all/wiki/check_mmm

You can call this plugin over nrpe. I'm already working on to fork a version which more useful with passive checks.

This plugin was developed by Ryan Lowe (Percona).

NOTE: Some answers included multiple products, these are all counted separately in the above figures.

There are a few products that are not listed at Monitoring MySQL in this list.

If you want to list what you use, please continue to use the MySQL Alert Monitoring Survey. Thanks to all those that replied.

There is no excuse to not have some MySQL Monitoring on your production system. At the worse case, you should be logging important MySQL information for later analysis. I use my own Logging and Analyzing scripts on every client for an immediate assessment regardless of what’s available. I combine that with my modified statpack to give me immediate text based analysis, broken down by hour chunks for quick reference. These help me in troubleshooting, but they are not a complete solution.

The most popular options I see and are also reflected in the results are:

• Cacti with MySQL Cacti Templates – Open Source
• Nagios used in conjunction with Cacti for alert monitoring – Open Source
• MONyog – Commercial with Free trial

There is a good list, including some products I did not know. My goal is to get this information included in the Monitoring-MySQL information site.

I have some additional information on Cacti and MONyog, and I’ll be sharing this information in upcoming posts.