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 [...]
Read/Write Splitting with PHP Webinar Questions Followup
Today I gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars. If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions. I answered as many as I could during the session, but here are [...]
Webinar on Read/Write Splitting with PHP
I’ll be presenting a webinar next Wednesday, January 23 at 10 a.m. (Pacific Time), about issues application developers should think about for scaling out read-query traffic using multiple MySQL instances in a replication pair. Specifically, about the care we have to take because replication is asynchronous. This means the slave may not have current data [...]
Is there room for more MySQL IO Optimization?
I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL [...]
Migrating several single standalone MySQL server to one Percona XtraDB Cluster… MariaDB to the rescue !
Some weeks ago I had to migrate some independent MySQL servers (some standard MySQL masters, and some just standalone) to a Percona XtraDB Cluster of 3 nodes. So the easiest way would be to configure each node to become also an asynchronous slave of one of the production servers. Like illustrated here: But in this [...]
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 [...]
Webinar: The Hazards of Multi-writing in a Dual-Master Setup
On November 15th at 1PM Eastern / 10 AM Pacific, I will be giving a webinar entitled “The Hazards of Multi-writing in a Dual-Master Setup“. In my experience many people do not understand the difficulty of managing writes to RDBMS datastores in a high availability environment, especially where asynchronous replication is used (which is almost everywhere). [...]
Percona XtraDB Cluster – installation and setup webinar follow up Q&A
Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before [...]
Minimizing Downtime from Lengthy AWS Outages
Well, it happened again… Another lengthy EBS outage in the US-East region impacted several sites across the net. While failures like this are rare, they can be quite costly and translate into headaches for the operations team when impact production systems for any length of time. At Percona, we routinely help clients architect and deploy [...]
MySQL 5.6.7-RC in tpcc-mysql benchmark
MySQL 5.6.7 RC is there, so I decided to test how it performs in tpcc-mysql workload from both performance and stability standpoints. I can’t say that my experience was totally flawless, I bumped into two bugs: MySQL 5.6.7 locks itself on CREATE INDEX MySQL 5.6.7-rc crashed under tpcc-mysql workload But at the end, is not [...]

