MySQL Administration Tools / News: Recent posts

The MyCAT project is an open-source tool-set for managing MySQL/Linux servers, currently composed of tools that: monitor replication, monitor and rotate binary logs, and allow remote shell access to arbitrary groups of servers.

Release 0.3.1 fixes a few critical bugs in both rep_mon and binlog_mon. In particular, binlog_mon could fail to delete logs even when disk space reaches 100%. Anyone using 0.3.0 should update right away.

I've uploaded some new screenshots to display the new tool (binlog_mon) and the improved output formatting in v0.3.0.

This is the first release that I consider beta quality, and the first release of the binary log monitoring tool, binlog_mon!

See the CHANGELOG for details of the many other improvements I've made.

Many thanks to David Lenwell of Digital Produce Inc. for building this web site (http://mycat.sourceforge.net/) in his spare time! He and I go a long way back, helping each other out with various projects and jobs. I look forward to seeing more great work come from him.

Some people are reporting that rep_mon is unable to connect to their MySQL server, or that it reports errors of being unable to authenticate. I've tracked this down to a conflict between the authentication methods used by Perl DBD::mysql and MySQL.

My suggestion is, if rep_mon is unable to authenticate with your MySQL server(s), check your Perl DBD::mysql version and the mysql libraries it was compiled against. If you can not install DBD::mysql 2.9004 and (re)compile it against mysql 4.1.7 or newer libraries, then you must adjust the password within MySQL for the user account that rep_mon will connect with. In brief, it is done like this:... read more

This morning I got word that there is a memory leak in 0.2.3's rep_mon (thanks Trevor!). I've uploaded 0.2.4 which fixes this critical problem.

I stronly urge anyone who has installed a previous version of Mycat to upgrade to 0.2.4 to avoid further memory leaks.

Bug fixes and more documentation in 0.2.3.

Over the next few weeks, I will be developing the database backup module, so check back soon!

I just uploaded 0.2.2. Changes are minor but noteworthy, mostly including more documentation and better handling of config file and command line options.

I just updated the README with more descriptive information about rcall and rep_mon, and a link to a how-to by O'Reilly on creating quick SSH logins (http://hacks.oreilly.com/pub/h/66).

http://mycat.sourceforge.net/README

Just completed the "rcall" tool, aka "Remote Call". This is extremely useful in situations where a sysadmin has many logical groups of servers (ie, web, database, etc), and needs to quickly run commands across them and view the ouput.

It does require a minor amount of configuration, but that is thoroughly discussed in the README. Essentailly, it is just a matter of specifying, in XML format, which servers are members of which groups, and what their respective hostnames are.

Just completed the replication monitor. Lots of info in the README and POD documentation! It runs very well for me - I'd like to find out how it works for other people.

Posted two screen shots of the tools in action.

I am in the process of re-writing the replication monitor (rep_mon). I have decided to post the existing file, so anyone interested can see what it does, and so that the changes I make are in CVS on SF.net