May 25, 2013

Intel 320 SSD write performance – contd.

I wrote about Intel 320 SSD write performance before, but I was not satisfied with these results. Somewhat each time on Intel 320 SSD I was getting different write performance, so it made me looking into this with details.

White Paper: Flashcache and MySQL on Virident drive

Our latest MySQL white paper is Improving Percona Server performance with Flashcache on the Virident tachIOn Drive. (Virident funded the research, but as always, we wrote the report ourselves.) The conclusion is that Flashcache can be good for read-heavy workloads, but more research is needed to understand its performance characteristics on write-heavy workloads. We explain [...]

Disaster: MySQL 5.5 Flushing

We raised topic of problems with flushing in InnoDB several times, some links: InnoDB Flushing theory and solutions MySQL 5.5.8 in search of stability This was not often recurring problem so far, however in my recent experiments, I observe it in very simple sysbench workload on hardware which can be considered as typical nowadays.

Recovering Linux software RAID, RAID5 Array

Dealing with MySQL you might need to deal with RAID recovery every so often. Sometimes because of client lacking the proper backup or sometimes because recovering RAID might improve recovery, for example you might get point in time recovery while backup setup only takes you to the point where last binary log was backed up. [...]

Make your file system error resilient

One of the typical problems I see setting up ext2/3/4 file system is sticking to defaults when it comes to behavior on errors. By default these filesystems are configured to Continue when error (such as IO error or meta data inconsistency) is discovered which can continue spreading corruption. This manifests itself in a worst way [...]

Intel 320 SSD read performance

(this is cross-post from http://www.ssdperformanceblog.com/) While PCI-e Flash cards show great performance, I am often asked about alternatives, as price for PCI-e cards is still significant and not acceptable for small companies and startups. Intel 320 SSD appears to be a popular drive with a quite acceptable price. I wrote about write performance of these [...]

Performance Schema overhead

As continuation of my CPU benchmarks it is interesting to see what is scalability limitation in MySQL 5.6.2, and I am going to check that using PERFORMANCE SCHEMA, but before that let’s estimate what is potential overhead of using PERFORMANCE SCHEMA. So I am going to run the same benchmarks (sysbench read-only and read-write) as [...]

Intel Nehalem vs AMD Opteron shootout in sysbench workload

Having two big boxes in our lab, one based Intel Nehalem (Cisco UCS C250) and second on AMD Opteron (Dell PowerEdge R815), I decided to run some simple sysbench benchmark to compare how both CPUs perform and what kind of scalability we can expect.

InnoDB page sizes: plans and ideas

It is well known fact that InnoDB standard page size is 16K or 16384 bytes. Sometime ago we added feature to Percona Server to change that to 4K or 8K (innodb_page_size). That maybe useful for SSD that operates with 4K blocks and you can get really much better throughput with 4K ( however we need [...]

InnoDB Flushing: a lot of memory and slow disk

You may have seen in the last couple of weekly news posts that Baron mentioned we are working on a new adaptive flushing algorithm in InnoDB. In fact, we already have three such algorithms in Percona Server (reflex, estimate, keep_average). Why do we need one more? Okay, first let me start by showing the current [...]