Author Archives: Axel Schwenke
Recently we had a report from a user who had seen a stunning 90% performance regression after upgrading his server to a Linux kernel with KPTI (kernel page-table isolation – a remedy for the Meltdown vulnerability). (more…) Read more
When you have read my previous blog post about MariaDB 10.1 GA performance, you have probably wondered why I didn’t include any numbers for MySQL 5.7. There are two reasons: first MySQL wasn’t GA at that time and secondly MySQL is not running stable on Power8.
Today I will come up with a comparison benchmark. I have chosen some more down-to-earth hardware for that because that is what the majority of our users will be running. Specifically it’s a SP-64 cloud machine from OVH. It has a 4-core Intel CPU and 64G of RAM. Disks aren’t fancy, but the benchmark is again a simplified read-only OLTP workload that runs from memory. Read more
This is a follow-up on my previous blog post about using Lua enabled sysbench. Today I will dive into how to write Lua scripts for sysbench. (more…) Read more
A quite common benchmark for MySQL is sysbench. It was written nearly 10 years ago by Alexey Kopytov.
Sysbench has modes to benchmark raw CPU performance, mutex speed, scheduler overhead and file IO performance. The probably most often used sysbench mode is OLTP. This benchmark mimics a OLTP scenario with small transactions hitting an optimized database. There are many variables to play with, most important is the number of simulated application threads (option –num-threads). The OLTP benchmark can be run read-only, then it does 14 SELECT queries per transaction. Or it can be run read-write which adds 2 UPDATEs and one INSERT and DELETE. Read more
Oracle has now launched MySQL-5.6.10-GA, so it is time to come up with some new benchmark results. The test candidates in this benchmark run are
- MySQL-5.5.29
- MySQL-5.6.10
- MariaDB-5.5.28a
- MariaDB-10.0.1
The 5.5 versions are in because I wanted to check for any regressions. In the past we have often seen performance regressions in newer versions which were caused by new features.
This time the benchmark was run on a different box. The main difference is that this box does not have SSD but a high performance RAID-5 with 512M of battery-backed cache. Read more
This article describes how I tuned MariaDB to give the best write throughput with SSD based storage.
When you have a write-heavy application writing into InnoDB, you will probably experience the InnoDB Checkpoint Blues. The effect manifests as stalls – short periods of time where the troughput falls to zero and I/O activity goes crazy. The phenomenon is well known and described i.e. here. More background about checkpointing can be found here.
The XtraDB fork of the InnoDB engine (and heart of Percona Server) contains some patches with the goal to overcome this odd behavior. Read more