Search Results for: write

Percona Server tree with support of Fusion-io atomic writes and DirectFS

Not so long ago Fusion-io announced an SDK which provides direct API access to Fusion ioMemory(tm) in addition to providing a native filesystem (directFS) with a goal to avoid overhead from kernel and regular Linux filesystems: ext4 and xfs. This requires a support from application, it should use special calls for IO. With help from […]

Fusion-io atomic writes and DirectFS

Not so far ago Fusion-io announced SDK which provides direct API access to Fusion ioMemory(tm) in addition to providing a native filesystem (directFS) with a goal to avoid overhead from kernel and regular Linux filesystems: ext4 and xfs. Fusion-io will explain these features during our Percona Live New York conference and share performance numbers. It […]

Write contentions on the query cache

While doing a performance audit for a customer a few weeks ago, I tried to improve the response time of their top slow query according to pt-query-digest‘s report. This query was run very frequently and had very unstable performance: during the time data was collected, response time varied from 50µs to 1s. When I ran […]

FusionIO 320GB MLC random write performance

I was advised that new drivers and new firmware for FusionIO cards improve performance and stability and it is recommended to review results I’ve got about year ago. Using the same methodology and the same box as for Intel 320 SSD, I run random writes benchmarks for FusionIO 320GB MLC card (I do not have […]

Intel 320 SSD random write performance

While I like performance provided by PCI-E cards like FusionIO or Virident tachIOn, I am often asked about SATA drives alternatives, as price of PCI-E cards often is barrier, especially for startups. There is wide range of SATA drives on market, and it is hard to pick one, but Intel SSD are probably one of […]

What’s a good buffer pool read/write ratio?

At Percona Live last week, someone showed me a graph from their Cacti monitoring system, using the templates that I wrote. It was the buffer pool pages read, written, and created. He asked me if the graph was okay. Shouldn’t there be a lot more pages read than written, he asked? It’s a great question. […]

Write performance on Virident tachIOn card

This is crosspost from https://www.percona.com/blog/. Disclaimer: The benchmarks were done as part of our consulting practice, but this post is totally independent and fully reflects our opinion. One of the biggest problems with solid state drives is that write performance may drop significantly with decreasing free space. I wrote about this before (https://www.percona.com/blog/2010/07/17/ssd-free-space-and-write-performance/), using a […]

SSD: Free space and write performance

( cross posting from SSD Performance Blog ) In previous post On Benchmarks on SSD, commenter touched another interesting point. Available free space affects write performance on SSD card significantly. The reason is still garbage collector, which operates more efficiently the more free space you have. Again, to read mode on garbage collector and write […]