Hi, I benchmarked MySQL 4.1.18 on FreeBSD 6.1 and Debian 3.1 using Super Smack 1.3 some days ago.
The benchmark table is CREATE TABLE `Account` ( `aid` int(11) NOT NULL auto_increment, `name` char(20) NOT NULL default '', `flag` int(11) NOT NULL default '0', `uidcount` int(11) NOT NULL default '0', `balance` int(11) NOT NULL default '0', `point` int(11) NOT NULL default '0', `blocktm` int(11) NOT NULL default '0', `ipnum` int(10) unsigned default NULL, `newdate` datetime default NULL, PRIMARY KEY (`aid`), UNIQUE KEY `name` (`name`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; And it has 10,000,000 rows. The SQL statement is update Account set balance= balance + 1 where aid=?; The result is followed: OS Clients Result(queries per second) TPS(got from iostat) FreeBSD6.1 50 516.1 about 2000 Debian3.1 50 49.8 about 200 The result surprise me. The MySQL Performance on FreeBSD6.1 is about 10 times of on Debian3.1，and the output of iostat also shows it. I know that MySQL uses fsync() to flush both the data and log files at default when using innodb engine( http://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html). Our evaluating computer only has a 10000RPM SCSI hard disk. I think it can do about 200 sequential fsync() calls per second if the fsync() is real. Is the fsync() on FreeBSD6.1 fake? I mean than the data is only written to the drives memory and so can be lost if power goes down. And how I can confirm this? If the fsync() is fake, how can I get the real fsync? Any comment is welcome! PS: 1. Our evaluating computer is DELL PowerEdge 1650。Its hardware configuration is followed: CPU: 2 * Intel Pentium III 1.33GHz 512KB Level 2 Cache(smp) Memory: 1024MB ECC SDRAM HD: SEAGATE ST336706LC（36GB Ultra160 SCSI 10000RPM） NIC : Intel(R) PRO/1000 Network Connection 2. Some important parameters in MySQL configuration file are here: log-bin sync_binlog=1 innodb_safe_binlog innodb_buffer_pool_size = 384M innodb_additional_mem_pool_size = 20M innodb_log_file_size = 100M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 regards, Leo Huang
