April 16, 2014

Percona XtraDB Cluster: Setting up a simple cluster

Percona XtraDB Cluster (PXC) is different enough from async replication that it can be a bit of a puzzle how to do things the Galera way.  This post will attempt to illustrate the basics of setting up 2 node PXC cluster from scratch. Requirements Two servers (could be VMs) that can talk to each other. […]

Percona XtraBackup 2.0.8 is now available

Percona is glad to announce the release of Percona XtraBackup 2.0.8 on September 4, 2013. Downloads are available from our download site here and Percona Software Repositories. Percona XtraBackup is the world’s only open-source, free MySQL hot backup software that performs non-blocking backups for InnoDB and XtraDB databases. This release is the current GA (Generally Available) stable release […]

When it’s faster to use SQL in MySQL NDB Cluster over memcache API

Memcache access for MySQL Cluster (or NDBCluster) provides faster access to the data because it avoids the SQL parsing overhead for simple lookups – which is a great feature. But what happens if I try to get multiple records via memcache API (multi-GET) and via SQL (SELECT with IN())? I’ve encountered this a few times […]

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 Server on the Raspberry Pi: Your own MySQL Database Server for Under $80

There are many reasons for wanting a small MySQL database server: You’re a uni student who wants to learn the SQL language better and needs a mini-testbox You’re a Windows user who wants to play around with Percona Server on Linux You’re a corporate application developer who wants a small SQL development & test box […]

How to start a Percona XtraDB Cluster

Before version 5.5.28 of Percona XtraDB Cluster, the easiest way was to join the cluster using wsrep_urls in [mysqld_safe] section of my.cnf. So with a cluster of 3 nodes like this : node1 = 192.168.1.1 node2 = 192.168.1.2 node3 = 192.168.1.3 we defined the setting like this :

With that line above in my.cnf […]

Timezone and pt-table-checksum

I recently worked through an issue with a client trying to detect data drift across some servers that were located in different timezones.  Unfortunately, several of the tables had timestamp fields and were set to a default value of CURRENT_TIMESTAMP.  From the manual, here is how MySQL handles timezone locality with timestamp fields: Values for TIMESTAMP columns are […]

Avoiding SST when adding new Percona XtraDB Cluster node

Some people want to use a backup to prepare a new Percona XtraDB Cluster node. They want this to avoid State Snapshot Transfer that could slow down the donor (depending of the SST method you are using, the donor can be blocked. I will cover this in a future blog post). As backup are generally […]

Percona XtraDB Cluster: Failure Scenarios with only 2 nodes

During the design period of a new cluster, it is always advised to have at least 3 nodes (this is the case with PXC but it’s also the same with PRM). But why and what are the risks ? The goal of having more than 2 nodes, in fact an odd number is recommended in […]

Troubleshooting MySQL Memory Usage

One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you have reasonable amount of connections but yet MySQL takes much more memory than you would expect, causing swapping or other […]