Preparing for my talk for Percona MySQL University in Raleigh,NC, Tuesday 29th of January I have created the outline of improvements available in MySQL 5.6 which I thought was worth sharing to give a feel for how massive work have been done for this release in variety of areas. I’m sure the list is not [...]
Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
I learn more and more about Galera every day. As I learn more, I try to keep my myq_gadgets toolkit up to date with what I consider is important to keep any eye on on a PXC node. In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over [...]
Understanding Multi-node writing conflict metrics in Percona XtraDB Cluster and Galera
I have addressed previously how multi-node writing causes unexpected deadlocks in PXC, at least, it is unexpected unless you know how Galera replication works. This is a complicated topic and I personally feel like I’m only just starting to wrap my head around it. The magic of Galera replication The short of it is that Galera [...]
Differences between READ-COMMITTED and REPEATABLE-READ transaction isolation levels
As an instructor with Percona I’m sometimes asked about the differences between the READ COMMITTED and REPEATABLE READ transaction isolation levels. There are a few differences between READ-COMMITTED and REPEATABLE-READ, and they are all related to locking.
Percona XtraDB Cluster: Multi-node writing and Unexpected deadlocks
Percona XtraDB Cluster (PXC) and the technology it uses (Galera) is an exciting alternative to traditional MySQL replication. For those who don’t know, it gives you: Fully Synchronous replication with a write latency increase equivalent to a ping RTT to the furthest node Automatic cluster synchronization, both incremental and full restores The ability to read [...]
Recovery deleted ibdata1
Recently I had a case when a customer deleted the InnoDB main table space – ibdata1 – and redo logs – ib_logfile*. MySQL keeps InnoDB files open all the time. The following recovery technique is based on this fact and it allowed to salvage the database. Actually, the files were deleted long time ago – [...]
Filling the tmp partition with persistent connections
The use of tmpfs/ramfs as /tmp partition is a common trick to improve the performance of on-disk temporary tables. Servers usually have less RAM than disk space so those kind of partitions are very limited in size and there are some cases were we can run out of space. Let’s see one example. We’re running [...]
How to Monitor MySQL with Percona’s Nagios Plugins
In this post, I’ll cover the new MySQL monitoring plugins we created for Nagios, and explain their features and intended purpose. I want to add a little context. What problem were we trying to solve with these plugins? Why yet another set of MySQL monitoring plugins? The typical problem with Nagios monitoring (and indeed with [...]
Making the impossible: 3 nodes intercontinental replication
In this post I want to show new possibilities which open with Percona XtraDB Cluster. We will create 3 nodes Cluster with nodes on different continents (Europe, USA, Japan) and each node will accept write queries. Well, you theoretically could create 3 node traditional MySQL ring replication, but this is not what you want to [...]
Percona Server 5.5.17-22.1 released
Percona is glad to announce the release of Percona Server 5.5.17-22.1 on November 19th, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.17, including all the bug fixes in it, Percona Server 5.5.17-22.1 is now the current stable release in the 5.5 series. All of Percona ‘s software is open-source and free, all the details of the release can [...]

