Continuous integration of new features and bug fixes is great – but what if a small change in seemingly insignificant code causes a major performance regression in overall server performance? We need to ensure this does not happen. That said, performance regressions can be hard to detect. They may hide for some time (or be […]
Quality Assurance: Percona Server Development Now Monitored by Automated Sysbench Performance Regression Checks!
Partha Dutta posted pretty interesting post about iSCSI vs SCSI performance using SysBench. This is nice to finally see some iSCSI benchmarks done with MySQL – something we were planning to do for a while but never ended up doing, mainly due to lack of hardware available for tests. It is also good to see […]
NOTE: This is part 1 of what will be a two-part series on the performance implications of using in-flight data encryption. Some of you may recall my security webinar from back in mid-August; one of the follow-up questions that I was asked was about the performance impact of enabling SSL connections. My answer was 25%, […]
In addition to the problem with trx_list scan we discussed in Friday’s post, there is another issue in InnoDB transaction processing that notably affects MySQL performance – for every transaction InnoDB creates a read view and allocates memory for this structure from heap. The problem is that the heap for that allocation is destroyed on […]
One major problem in terms of MySQL performance that still stands in the way of InnoDB scalability is the trx_list scan on consistent read view creation. It was originally reported as a part of MySQL bug #49169 and can be described as follows. Whenever a connection wants to create a consistent read, it has to […]
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. […]
Last time I wrote about memory allocators and how they can affect MySQL performance in general. This time I would like to explore this topic from a bit different angle: What impact does the number of processor cores have on different memory allocators and what difference we will see in MySQL performance in this scenario? […]
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 […]
In my raw IO benchmark of Intel 520 SSD we saw that the drive does not provide uniform throughput and response time, but it is interesting how does it affect workload if it comes from MySQL. I prepared benchmarks results for Sysbench OLTP workload with MySQL running on Intel 520. You can download it there.
Sysbench has three distribution for random numbers: uniform, special and gaussian. I mostly use uniform and special, and I feel that both do not fully reflect my needs when I run benchmarks. Uniform is stupidly simple: for a table with 1 mln rows, each row gets equal amount of hits. This barely reflects real system, […]