April 24, 2014

MySQL 5.6 – InnoDB Memcached Plugin as a caching layer

A common practice to offload traffic from MySQL 5.6 is to use a caching layer to store expensive result sets or objects.  Some typical use cases include: Complicated query result set (search results, recent users, recent posts, etc) Full page output (relatively static pages) Full objects (user or cart object built from several queries) Infrequently […]

Why MySQL Performance at Low Concurrency is Important

A few weeks ago I wrote about “MySQL Performance at High Concurrency” and why it is important, which was followed up by Vadim’s post on ThreadPool in Percona Server providing some great illustration on the topic. This time I want to target an opposite question: why MySQL performance at low concurrency is important for you. […]

Investigating MySQL Replication Latency in Percona XtraDB Cluster

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 […]

Why do we care about MySQL Performance at High Concurrency?

In many MySQL Benchmarks we can see performance compared with rather high level of concurrency. In some cases reaching 4,000 or more concurrent threads which hammer databases as quickly as possible resulting in hundreds or even thousands concurrently active queries. The question is how common is it in production ? The typical metrics to use […]

Analyzing Slow Query Table in MySQL 5.6

Next week I’m teaching an online Percona Training class, called Analyzing SQL Queries with Percona Toolkit.  This is a guided tour of best practices for pt-query-digest, the best tool for evaluating where your database response time is being spent. This month we saw the GA release of MySQL 5.6, and I wanted to check if any […]

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 […]

How to find MySQL queries worth optimizing ?

One question I often get is how one can find out queries which should be optimized. By looking at pt-query-digest report it is easy to find slow queries or queries which cause the large portion of the load on the system but how do we know whenever there is any possibility to make this query […]

Adaptive flushing in MySQL 5.6 – cont

This is to continue my previous experiments on adaptive flushing in MySQL 5.6.6. Now I am running Ubuntu 12.04, which seems to provide a better throughput than previous system (CentOS 6.3), it also changes the profile of results. So, as previous I run tpcc-mysql 2500W, against MySQL 5.6.6 with innodb_buffer_pool_size 150GB, and now I vary […]

DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL

Suppose you have turned on innodb_file_per_table (which means that each table has its own tablespace), and you have to drop tables in a background every hour or every day. If its once every day then you can probably schedule the table dropping process to run during off-peak hours. But I have seen cases where the […]

Percona Server vs MySQL on Intel 320 SSD

If you are terrified by the stability of the results in MySQL in my previous post, I am going to show what we can get with Percona Server. This is also to address the results presented there Benchmarking MariaDB-5.3.4