October 22, 2014

Galera replication – how to recover a PXC cluster

Galera replication for MySQL brings not only the new, great features to our ecosystem, but also introduces completely new maintenance techniques. Are you concerned about adding such new complexity to your MySQL environment? Perhaps that concern is unnecessarily. I am going to present here some simple tips that hopefully will let fresh Galera users prevent […]

Measuring Max Replication Throughput on Percona XtraDB Cluster with wsrep_desync

Checking throughput with async MySQL replication Replication throughput is the measure of just how fast the slaves can apply replication (at least by my definition).  In MySQL async replication this is important to know because the single-threaded apply nature of async replication can be a write performance bottleneck.  In a production system, we can tell […]

Multicast replication in Percona XtraDB Cluster (PXC) and Galera

Bandwidth multiplication and synchronous clusters I’ve seen a lot of people setting up clusters with 3-6+ nodes on 1 Gbps networks.  1 Gbps seems like a lot, doesn’t it?  Actually, maybe not as much as you think.  While the theoretical limit of 1Gbps is actually 120MBps, I start to get nervous around 100MBps. By default […]

Percona XtraDB Cluster for MySQL and encrypted Galera replication

Few people realize that Galera/Percona XtraDB (PXC) replication can be encrypted via SSL for secure transfer of your replicated data.  Setting this up is actually quite easy to do and probably will look familiar to a lot of people. Setting up SSL and Galera Create and propagate a single key/cert pair First, we create a […]

Investigating MySQL Replication Latency in Percona XtraDB Cluster

I was curious to check how Percona XtraDB Cluster behaves when it comes to MySQL replication latency — or better yet, call it data propagation latency. It was interesting to see whenever I can get stale data reads from other cluster nodes after write performed to some specific node. To test it I wrote quite a […]

Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN

I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment.  They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against each other. Test Environment The test environment included AWS EC2 nodes in US-East and US-West (Oregon).  The ping RTT latency […]

Percona XtraDB Cluster Feature 2: Multi-Master replication

This is about the second great feature – Multi-Master replication, what you get with Percona XtraDB Cluster. It is recommended you get familiar with general architecture of the cluster, described on the previous post. By Multi-Master I mean the ability to write to any node in your cluster and do not worry that eventually you […]

MySQL ring replication: Why it is a bad option

I’ve recently worked with customers using replication rings with 4+ servers; several servers accepting writes. The idea behind this design is always the same: by having multiple servers, you get high availability and by having multiple writer nodes, you get write scalability. Alas, this is simply not true. Here is why. High Availability Having several […]

Should you migrate to Percona XtraDB Cluster?

Interest in Percona XtraDB Cluster / Galera has been high ever since we introduced the product in 2012.  I typically have a conversation about Galera and Percona XtraDB Cluster (PXC) at least once a week with a consulting customer who wants to know if it will be a good fit for their application.  Last week […]

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 […]