July 28, 2014

Crash-resistant replication: How to avoid MySQL replication errors

Percona Server’s “crash-resistant replication” feature is useful in versions 5.1 through 5.5. However, in Percona Server 5.6 it’s replaced with Oracle MySQL 5.6′s “crash safe replication” feature, which has it’s own implementation (you can read more about it here). A MySQL slave normally stores its position in files master.info and relay-log.info which are updated by […]

Confusing MySQL Replication Error Message

I already wrote about some MySQL Error Messages which are confusing, here is one more:

After setting up new slave Server I’m getting error log file flooded with messages like this and there is no hint in the message what would explain what is wrong. In fact the issue in this case is (because […]

GTIDs in MySQL 5.6: New replication protocol; new ways to break replication

One of the MySQL 5.6 features many people are interested in is Global Transactions IDs (GTIDs). This is for a good reason: Reconnecting a slave to a new master has always been a challenge while it is so trivial when GTIDs are enabled. However, using GTIDs is not only about replacing good old binlog file/position […]

Row-based replication, MySQL 5.6 upgrades and temporal data types

Whither your rollback plan? MySQL 5.6 upgrades are in full swing these days and knowing how to safely upgrade from MySQL 5.5 to 5.6 is important. When upgrading a replication environment, it’s important that you can build a migration plan that safely allows for your upgrade with minimal risk — rollback is often a very […]

How to identify and cure MySQL replication slave lag

Here on the Percona MySQL Support team, we often see issues where a customer is complaining about replication delays – and many times the problem ends up being tied to MySQL replication slave lag. This of course is nothing new for MySQL users and we’ve had a few posts here on the MySQL Performance Blog […]

MySQL 5.6 New Replication Features: Webinar followup Q&A

I want to thank all attendees of my webinar, “MySQL 5.6 New Replication Features: Benefits, Challenges and Limitations“. We had questions that I didn’t have the time to answer: Q: If I run on Amazon’s RDS, do I need to worry about enabling crash-safe slaves, or is that already in place? A: Crash-safe replication is […]

5 reasons why MySQL replication lag is flapping between 0 and XXXXX

Working day to day with Percona Remote DBA customers, we have been facing an issue from time to time when MySQL replication lag is flapping between 0 and XXXXX constantly – i.e. Seconds_Behind_Master is 0 for a few secs, then it’s like 6287 or 25341, again 0 and so on. I would like to note […]

Replication in MySQL 5.6: GTIDs benefits and limitations – Part 1

Global Transactions Identifiers are one of the new features regarding replication in MySQL 5.6. They open up a lot of opportunities to make the life of DBAs much easier when having to maintain servers under a specific replication topology. However you should keep in mind some limitations of the current implementation. This post is the […]

Is Synchronous Replication right for your app?

I talk with lot of people who are really interested in Percona XtraDB Cluster (PXC) and mostly they are interested in PXC as a high-availability solution.  But, what they tend not to think too much about is if moving from async to synchronous replication is right for their application or not. Facts about Galera replication […]

Disconnecting a replication slave is easier with MySQL 5.5+ (RESET SLAVE vs. RESET SLAVE ALL)

It’s not uncommon to promote a server from slave to master. One of the key things to protect your data integrity is to make sure that the promoted slave is permanently disconnected from its old master. If not, it may get writes from the old master, which can cause all kinds of data corruption. MySQL […]