July 31, 2014

Failover with the MySQL Utilities: Part 2 – mysqlfailover

In the previous post of this series we saw how you could use mysqlrpladmin to perform manual failover/switchover when GTID replication is enabled in MySQL 5.6. Now we will review mysqlfailover (version 1.4.3), another tool from the MySQL Utilities that can be used for automatic failover. Summary mysqlfailover can perform automatic failover if MySQL 5.6′s […]

Why %util number from iostat is meaningless for MySQL capacity planning

Earlier this month I wrote about vmstat iowait cpu numbers and some of the comments I got were advertising the use of util% as reported by the iostat tool instead. I find this number even more useless for MySQL performance tuning and capacity planning. Now let me start by saying this is a really tricky and deceptive number. Many […]

Using MySQL 5.6 Performance Schema in multi-tenant environments

Hosting a shared MySQL instance for your internal or external clients (“multi-tenant”) was always a challenge. Multi-tenants approach or a “schema-per-customer” approach is pretty common nowadays to host multiple clients on the same MySQL sever. One of issues of this approach, however, is the lack of visibility: it is hard to tell how many resources (queries, disk, […]

ScaleArc: Real-world application testing with WordPress (benchmark test)

ScaleArc recently hired Percona to perform various tests on its database traffic management product. This post is the outcome of the benchmarks carried out by me and ScaleArc co-founder and chief architect, Uday Sawant. The goal of this benchmark was to identify ScaleArc’s overhead using a real-world application – the world’s most popular (according to […]

ScaleArc: Benchmarking with sysbench

ScaleArc recently hired Percona to perform various tests on its database traffic management product. This post is the outcome of the benchmarks carried out by Uday Sawant (ScaleArc) and myself. You can also download the report directly as a PDF here. The goal of these benchmarks is to identify the potential overhead of the ScaleArc […]

Percona Cloud Tools: Making MySQL performance easy

One of our primary focuses at Percona is performance. Let me make some statements on what is “performance.” In doing so I will refer to two pieces of content: Carry Millsap’s talk “Performance Instrumentation: Beyond What You Do Now” [1] White Paper (by Peter and Baron) “Goal-Driven Performance Optimization” [2] I highly recommend that you […]

Impact of memory allocators on MySQL performance

MySQL server intensively uses dynamic memory allocation so a good choice of memory allocator is quite important for the proper utilization of CPU/RAM resources. Efficient memory allocator should help to improve scalability, increase throughput and keep memory footprint under the control. In this post I’m going to check impact of several memory allocators on the […]

How Innodb Contention may manifest itself

Even though multiple fixes have been implemented in Percona Server and MySQL 5.5, there are still workloads in which case mutex (or rw-lock) contention is a performance limiting factor, helped by ever growing number of cores available in the systems. It is interesting though the contention may manifest itself in the different form from the […]

Cache Miss Storm

I worked on the problem recently which showed itself as rather low MySQL load (probably 5% CPU usage and close to zero IO) would spike to have hundreds instances of threads running at the same time, causing intense utilization spike and server very unresponsive for anywhere from half a minute to ten minutes until everything […]

When is it a time to upgrade memory ?

Quite commonly I get a question similar to this – “My Innodb Buffer Pool is already 90% full, should I be thinking about upgrading memory already?” This is a wrong way to put the question. Unless you have very small database (read as database which is less than innodb_buffer_pool_size) You will have all buffer pool […]