Checksum is a standard practice among DBAs to verify the data consistency across replicated nodes. In this post we’re going to review the syncing options for an inconsistent MySQL slave of Galera cluster node.

Here we’re assuming a setup of regular replication to a MySQL instance from one of the Galera cluster nodes.

In the usual MySQL replication setup, standard practice involves the usage of the pt-table-checksum tool to identify the discrepancies and usage of pt-table-sync to bring them in sync. The checksum tool, pt-table-checksum, can run across Galera cluster node to verify the data consistency and confirm if the MySQL slave is consistent with a chosen primary node.

What happens if this Galera cluster’s regular MySQL slave sees data inconsistency on it? Will pt-table-sync work there? The answer to this depends…
pt-table-sync when used with –sync-to-master …

The Open DB Camp in Sardinia 2011 has had a number of sessions on varying topics. Topics range from MySQL over MongoDB to replication and High Availability.

I decided to tap into the database expert resources present here at Sardegna Ricerche by discussing a non-database issue, where one can expert database experts to have insights beyond those of end users. And they did.

The topic was the particular case of information overload many of us suffer from on our hard disks: Too many files, too hard to find.

• How do we find the bank statement from April 2007 from the more-seldom-used account?
• What are the ten best work-related pictures from last year?
• Is this the most current …

In October 2008, Baron posted How to Check MySQL Replication Integrity Continually. Here at Pythian we have developed a method based on that post, and added “verifying that masters and slaves are in sync” to our standard battery of tests.

We call it “Continual replication sync checking”. This article will explain how it works, how to test and make the procedure non-blocking, benchmarks from the real world, issues we encountered along the way, and …

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I am considering taking some time off work to concentrate deeply on MySQL Table Sync, which has been getting usage in very large companies whose names we all know. There are a lot of bugs and feature requests outstanding for it. It is overly complex, needs a lot of work, and I can't do it in one-hour or even three-hour chunks. I need to focus on it. I'm considering asking for a bounty of $2500 USD for this. Please let me know what you think of this; it seems to be a successful way to sponsor development on some other projects, like Vim.

For the amount of time I think this will take, $2500 is far below my per-hour consulting rate; I considered setting the bounty higher, but I think this will be a fair amount.

I would not begin this project before December at the earliest, so there's some time to raise funds and time for me to continue working on High Performance …