Testing a replicated backup system

Testing a replicated backup system

If you have a high need for availability for a production application, but don’t have the money to invest in full fault tolerance networking, machinery, and access, you’ll need to have some sort of realtime backup system in place should your primary environment go down. This poses the issue of how do you keep one system on standbye, but be sure that it’s ready to go at all times. The image below shows one possible setup. The...

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Resync a double replicated MySQL Database

Resync a double replicated MySQL Database

Certain scenarios need a master database replicated to multiple slaves instead of just one. If you have a very heavy read application you might benefit from a number of slaves. It also provides a sort of double backup if one slave drifts away from the data it’s supposed to have. Double replication also allows you to test a backup system. I have a separate article dedicated to that. With a double replication you’ll have a setup like...

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MySQL Replication Re-Syncing

MySQL Replication Re-Syncing

I may be in the minority here, but I’ve spent alot of time resyncing my MySQL replication slaves. They just seem to drift away from an exact duplicate of the master. Here’s a quick list of tips to remember when performing this task. Make sure you STOP the MySQL service on the master before you make your snapshot.  Otherwise you’ll have no idea where to start your slaves.  When you restart the service, you’ll see what...

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Abstract MySQL Selects

Sometimes if you have a rapidly changing database, you have to do maintenance on tables, but you may not want to keep updating your script to account for new tables and/or columns you create. If this is the case, you have to make your code a little more abstract. MySQL has a few commands that help with this. For instance, if you are replicating a set of databases to another server, and want to make sure the replication is up to date, you could...

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Mysql Replication Issues and Errors

Everywhere I look I see articles about how easy it is to set up replication in MySQL.  I will admit that it’s easy, but at what cost?  I am not comfortable enough with MySQL’s replication to just set it and forget it.  It’s been difficult to keep things synchronized between the master and slave. As I work this out, I’ll be adding links and comments to this post.  There’s alot of good material out there, and...

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