September 18, 2014

How to know if you’re updating Slave you should not ?

When replication runs out of sync first question you often ask is if someone could be writing to the slave. Of course there is read_only setting which is good to set in the slave but it is not set always and also users with SUPER privilege bypass it. Looking into binary log is obvious choice […]

How SHOW SLAVE STATUS relates to CHANGE MASTER TO

As you probably know MySQL Replication (statement based) works by fetching statements from MASTERs binary log and executing them on the SLAVE. Since MySQL 4.0 this process is a bit more involved having events passing via relay logs on the Slave which also means there are two replication threads “IO Thread” and “SQL Thread” used […]

Managing Slave Lag with MySQL Replication

The question I often get is how far MySQL may fall behind and how to keep replication from lagging. The lag you will see will vary a lot from application to the application and from load to load. Plus what is the most important within same application the lag will likely have spikes – most […]

Master-Master or Master with Many Slaves

I just found post by Kevin, in which he criticizes Master-Master approach, finding Master with many slaves more optimal. There is surely room for master-N-slaves systems but I find Master-Master replication much better approach in many cases. Kevin Writes “It requires extra hardware thats sitting in standby and not being used (more money and higher […]

Getting use of Slave in MySQL Replication

MySQL Replication is asynchronous which causes problems if you would like to use MySQL Slave as it can contain stale data. It is true delay is often insignificant but in times of heavy load or in case you was running some heavy queries on the master which not take time to replicate to the slave […]

OpenStack users shed light on Percona XtraDB Cluster deadlock issues

I was fortunate to attend an Ops discussion about databases at the OpenStack Summit Atlanta this past May as one of the panelists. The discussion was about deadlock issues OpenStack operators see with Percona XtraDB Cluster (of course this is applicable to any Galera-based solution). I asked to describe what they are seeing, and as […]

Multi-Valued INSERTs, AUTO_INCREMENT & Percona XtraDB Cluster

A common migration path from standalone MySQL/Percona Server to a Percona XtraDB Cluster (PXC) environment involves some measure of time where one node in the new cluster has been configured as a slave of the production master that the cluster is slated to replace. In this way, the new cluster acts as a slave of […]

Using MySQL 5.6 Global Transaction IDs (GTIDs) in production: Q&A

Thank you to all of you who attended my webinar last week about Global Transaction IDs (GTIDs), which were introduced in MySQL 5.6 to make the reconfiguration of replication straightforward. If you missed my webinar, you can still listen to the recording and download the sides (free). We had a lot of questions during the […]

Percona Server 5.6.20-68.0 is now available

Percona is glad to announce the release of Percona Server 5.6.20-68.0 on August 29, 2014. Download the latest version from the Percona web site or from the Percona Software Repositories. Based on MySQL 5.6.20, including all the bug fixes in it, Percona Server 5.6.20-68.0 is the current GA release in the Percona Server 5.6 series. All of Percona’s […]

Measuring failover time for ScaleArc load balancer

ScaleArc hired Percona to benchmark failover times for the ScaleArc database traffic management software in different scenarios. We tested failover times for various clustered setups, where ScaleArc itself was the load balancer for the cluster. These tests complement other performance tests on the ScaleArc software – sysbench testing for latency and testing for WordPress acceleration. […]