Tag: MMM-Cluster
MySQL Master-Master Replication Manager 1.0 Released
29 Oct2007

It’s been a long time since we’ve started this project and it is time to make a checkpoint. So, I’ve decided to release final 1.0 version and make 1.X branch stable while all serious development with deep architectural changes will be done 2.X branch (trunk at this moment).

Changes from previous release:

  • Perl semaphores implementation caused huge memory leaks (mmmd_mod).
  • Now we do not send any commands to hard offline hosts with dead TCP/IP stack to prevent mointoring problems for other hosts.
  • Removed legacy StartSlave method from agent code which caused problems on some Perl versions
  • Added a few fixes to prevent non-exclusive roles from moving. This caused internal status structures to be corrupted.
  • Made all mysql checks properly report errors occurring (previously they were resulting in an OK response). Thanks to Phillip Pearson.
  • Some memory leaks found in mysql checkers and as a quick fix we’ve added an idea of “Maximum Checks Before Restart” to all checkers. If you want some checker to restart after N checks, simply add “restart after N” to your checker declaration.
  • Added some more docs to the project site.

New version can be obtained here or from the project’s SVN repository.


Linux User in Solaris 10 Survival Guide
28 Sep2007

This week aside from tons of different tasks I was working on one of MMM users complaint regarding some issues with MMM on Solaris 10. I knew that this OS has not so user (admin) friendly environment (especially for people with strong GNU-related background), but had no other options and decided to install Solaris 10 in VMWare Fusion on my desktop.

Installation was a bit strange comparing to Debian/RHEL/Ubuntu and FreeBSD where I have a strong experience, but I’ve managed to install it successfully. The major problem after my first boot was a lack of knowledge about how things could be done in Solaris… Below I’ll describe what generic Linux admin could do with Solaris to make it easier to use and more friendly for GNU-addicted mind ;-)

Notice: If you’re Solaris administrator, please, don’t read further because I’m pretty sure that all these suggestions would look dumb for you (I knew some old solaris admins before and they hated GNU environments).

Read the rest of this entry


MMM Release 1.0-pre4
16 May2007

New alpha release 1.0-pre4 of the MySQL Master-Master Replication Manager. This release has lots of major fixes and I’m glad to announce first sponsored port of mmm to non-linux platform – it has been ported to Solaris 10. So, here are our changes in this version:

  • Real checks timeouts – I’ve found and fixed lots of problems in checks timeout code and now if you specified in your mmm_mon.conf, that some check should timeout in 5 sec, it would timeout correctly on all supported platforms.
  • External third-party tools using – On all supported non-linux platforms mmm will use system binaries for fping and arp_ping so porting to another platforms would be much easier.
  • Agent notifications fix – Now we don’t try to notify dead agents about cluster changes and additionally we have 10 sec timeout on notification sends to prevent monitoring from lagging on network connection timeouts.
  • Bundled fping and send_arp – We have both used third-party tools used in mmm bundled in our distribution as separate build trees (you could find and build/install them from contrib directory).
  • Flexible perl binary location – We’re using “#!/usr/bin/env perl” as shebang line in our perl scripts so you can use any perl interpreter just by placing it earlier in your PATH variable.

Notice: If you’ll try to install this version, try to run bin/sys/fping and bin/sys/send_arp on your server before installation. If you’ll notice any errors, feel free to build binaries for your platform using contrib/* sources (you’ll need gcc and libnet installed).

So, as you can see, mmm development goes forward and we’re fixing some problems trying to make this software mature. If you want to help us, you can send your comments to mmm-devel mailing list, post your bug reports to our bug tracking or sponsor any changes you need ;-)


MMM Release 1.0-pre3
6 May2007

MySQL Master-Master Replication Manager version 1.0-pre3 has been released today. Changes list is really short now:

  • Major fix in multiple clusters support – now you can use many clusters with one monitoring node (details are in mmmd_mon man page)
  • Man pages for mmmd_mon, mmmd_agent and mmm_control scripts
  • Startup scripts added/fixed for mmmd_mon and mmmd_agent
  • Installation script now requires iproute package to be installed on server.

As always, if you have any questions/suggestions, post them here or in mmm-devel mail list.