Before I begin, a disclaimer. VoltDB is not a customer, and did not pay Percona or me to investigate VoltDB’s scalability or publish this blog post. More disclaimers at the end. Short version: VoltDB is very scalable; it should scale to 120 partitions, 39 servers, and 1.6 million complex transactions per second at over 300 [...]
Shard-Query adds parallelism to queries
November 15, 2010 By 18 Comments
Preamble: On performance, workload and scalability: MySQL has always been focused on OLTP workloads. In fact, both Percona Server and MySQL 5.5.7rc have numerous performance improvements which benefit workloads that have high concurrency. Typical OLTP workloads feature numerous clients (perhaps hundreds or thousands) each reading and writing small chunks of data. The recent improvements to [...]
Lost innodb tables, xfs and binary grep
November 9, 2010 By 12 Comments
Before I start a story about the data recovery case I worked on yesterday, here’s a quick tip – having a database backup does not mean you can restore from it. Always verify your backup can be used to restore the database! If not automatically, do this manually, at least once a month. No, seriously [...]
Analyzing the distribution of InnoDB log file writes
July 16, 2010 By 5 Comments
I recently did a quick analysis of the distribution of writes to InnoDB’s log files. On a high-traffic commodity MySQL server running Percona XtraDB for a gaming workload (mostly inserts to the “moves” table), I used strace to gather statistics about how the log file writes are distributed in terms of write size. InnoDB writes [...]
Scaling: Consider both Size and Load
July 13, 2010 By 5 Comments
So lets imagine you have the server handling 100.000 user accounts. You can see the CPU,IO and Network usage is below 10% of capacity – does it mean you can count on server being able to handle 1.000.000 of accounts ? Not really, and there are few reasons why, I’ll name most important of them: [...]
Why you should ignore MySQL’s key cache hit ratio
February 28, 2010 By 28 Comments
I have not caused a fist fight in a while, so it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL’s key cache hit ratio is wrong, even when you hear it from experts. There are two major problems with the key buffer hit ratio, and [...]
MySQL-Memcached or NOSQL Tokyo Tyrant – part 3
October 19, 2009 By 25 Comments
This is part 3 of our series. In part 1 we talked about boosting performance with memcached on top of MySQL, in Part 2 we talked about running 100% outside the data with memcached, and now in Part 3 we are going to look at a possible solution to free you from the database. The [...]
Quick comparison of MyISAM, Infobright, and MonetDB
September 29, 2009 By 30 Comments
Recently I was doing a little work for a client who has MyISAM tables with many columns (the same one Peter wrote about recently). The client’s performance is suffering in part because of the number of columns, which is over 200. The queries are generally pretty simple (sums of columns), but they’re ad-hoc (can access [...]
Off to California!
September 10, 2009 By 5 Comments
Today’s the day I fly to Los Angeles to teach a private training class, en route to Santa Clara/San Francisco for our public training workshops next week.
Our Montreal practice teach at Station-C went great – it was an opportunity to do a road test and iron out any kinks in the delivery.
What did I learn in the process?
Give me 8 hours, and I’ll help you build a better application
August 29, 2009 By 4 Comments
I have run into a number of cases recently that all had a similar look and feel. In most of these cases, the symptoms were very complicated, but they boiled down to just a few problems that can be prevented in very simple ways. If you are not doing any of the following three simple [...]
