Monthly Archive for April, 2008

Taking KMRT

I went to Kaohsiung last weekend, and took KMRT, which officially started passenger service in March 2008.

The World Games Station.

Kaohsiung Main Station. There are platform screen doors for all underground stations.

Central Park Station.

I feel the KMRT is very like TMRT, but it is more crowded because of only 3 carriages for each train.
And the turnstiles are not functioned so well. I failed to return the single journey ticket in my 3 trips, and tried for the second time for success.

Employee of a Web Company Traveling…


MySQL on Mtron SSD

We (PIXNET) have bought 2 Mtron MSP-SATA70 (Spec: write 90MB/s, read 120MB/s), installed on 8-way, 12 G RAM, running Debian Linux x64 and MySQL 5.1 Slave Server. We use MyISAM as backend, and the largest MyISAM table is about 3GB.

We setup the SSDs with RAID 0, 4KB stripe size, XFS, and noop disk scheduler. In the beginning, we spend about one-third time to copy data from master server than the time spent copying from 2 SCSI 10k RPM HDDs (RAID 0). The rate is about 70MB/s. When replicating, we have about 3000~4000 qps, and the largest qps is about 15000.

In production use (consists SELECT and UPDATE queries), we have 8000 qps then get CPU bound. Some complicated SQL queries start blocking. If we only execute simple SELECT queries, 15000 qps is possible.