mariadb 5.5.30 released

[scott]

This is my first stab at mariadb packages for el6-fedora 18. Some things to know in advance:

* Mariadb is a community fork of Mysql. It does everything mysql does, and even uses mysql filenames.
* While I could have written it to Obsolete mysql, I did not do that so you will need to remove mysql to install it.
* As far as I have seen so far, it is completely compatible with existing mysql dbs. I even upgraded over mysql 5.1 (when I did have obsoletes enabled) and it went through just fine.
* Allegedly it can do masterless replication. Havent tried that yet, but I want to
* Existing applications should not have to change to talk to mariadb

[scott]

Im going to work this up into a blog post or something, I have gotten the masterless replication going using galera (not packaged yet, but soon) working with mariadb. Its possible to implement this in mysql as well, so I'll treat it like a feature candidate.

As this patch was only available for 5.5.29, I rolled mariadb back to that version and dropped 5.5.30 from the repo. EL5 packages were also added to this branch.

[scott]

Masterless replication is set up between 2 project gamera servers, creating a shared bayes & awl db across nodes. No corruptions after 24 hours, so we'll continue to let this go over a few days.

Challenges so far:
1) firewall rules can get complicated
2) timing matters on intial setup (servers have to be started in order)

As I noted before, its possible to include this in the mysql packages, and its probably something I'll do. Especially given the inter-dependencies with mysql libraries and the fact that I dont (yet) want to tag MariaDB as Obsoletes on mysql.

[scott]

two other notes to add:

1) this works best with odd numbers of servers, but even if you dont have an odd number galera has an arbintration daemon to act as that 3rd party. Very briliant idea

2) I have now expanded this design with haproxy, to allow for a single IP for applictions to point to. This could be implemented two ways, the first is to run haproxy on a separate layer with IP failover (keepalived, LVS, etc) or by running haproxy locally on each mysql connecting node (an alternate here is sqlproxy, which I will also be exploring).

3) I have now set up 2 separate production environments with these designs that will make it into the final article.

[scott]

In case anyone was watching the news the other day, Wikipedia has partially completed their migration from mysql to mariadb.

[prupert]

Looks promising. I will soon try building a cluster of MariaDB servers using your packages. Are all requirements (including the MariaDB Galera Cluster packages) available in the Atomic repository? Anything out-of-the-ordinary I should take into consideration when using your packages in stead of the ones provided by MariaDB (https://kb.askmonty.org/en/installing-mariadb-with-yum/)?

[scott]

Its all in there for el6, for el5 you'll need to grab galera from the mariadb site.