经过一段时间的测试,准备把MySQL?5.1?InnoDB?Plugin部署到线上，今天发现MySQL?5.0?InnoDB?和MySQL5.1?InnoDB?Plugin启动是有点区别的，这里做一个整理
5.0MySQL?的版本信息
mysql>?show?variables?like?’%version%’;
+————————-+—————————–+
|?Variable_name???????????|?Value???????????????????????|
+————————-+—————————–+
|?protocol_version????????|?10??????????????????????????|
|?version?????????????????|?5.0.38-Debian_3netease5-log?|
|?version_comment?????????|?Debian?etch?distribution????|
|?version_compile_machine?|?x86_64??????????????????????|
|?version_compile_os??????|?pc-linux-gnu????????????????|
+————————-+—————————–+
5?rows?in?set?(0.01?sec)
启动的日志信息
InnoDB:?The?first?specified?data?file?xxx//ibdata1?did?not?exist:
InnoDB:?a?new?database?to?be?created!
100609?19:18:50??InnoDB:?Setting?file?xxx//ibdata1?size?to?32?MB
InnoDB:?Database?physically?writes?the?file?full:?wait…
100609?19:18:51??InnoDB:?Log?file?xxx/ib_logfile0?did?not?exist:?new?to?be?created
InnoDB:?Setting?log?file?xxx/ib_logfile0?size?to?128?MB
InnoDB:?Database?physically?writes?the?file?full:?wait…
InnoDB:?Progress?in?MB:?100
100609?19:18:53??InnoDB:?Log?file?xxx/ib_logfile1?did?not?exist:?new?to?be?created
InnoDB:?Setting?log?file?xxxx/ib_logfile1?size?to?128?MB
InnoDB:?Database?physically?writes?the?file?full:?wait…
InnoDB:?Progress?in?MB:?100
InnoDB:?Doublewrite?buffer?not?found:?creating?new
InnoDB:?Doublewrite?buffer?created
InnoDB:?Creating?foreign?key?constraint?system?tables
InnoDB:?Foreign?key?constraint?system?tables?created
100609?19:18:57??InnoDB:?Started;?log?sequence?number?0?0
100609?19:18:57?[Note]?/usr/sbin/mysqld:?ready?for?connections.
Version:?’5.0.38-Debian_3netease5-log’??socket:?xxx/mysqld.sock’??port:?4591??Debian?etch?distribution
MySQL?5.1?的版本信息
mysql>??show?variables?like?’%version%’;
+————————-+———————+
|?Variable_name???????????|?Value???????????????|
+————————-+———————+
|?innodb_version??????????|?1.0.6-unknown???????|?##这个是InnoDB?Plugin的新信息
|?protocol_version????????|?10??????????????????|
|?version?????????????????|?5.1.45-log??????????|
|?version_comment?????????|?Source?distribution?|
|?version_compile_machine?|?x86_64??????????????|
|?version_compile_os??????|?unknown-linux-gnu???|
+————————-+———————+
MySQL5.1?InnoDB?Plugin启动日志信息，多了很多内容，下面逐一介绍
InnoDB:?The?InnoDB?memory?heap?is?disabled
InnoDB:?Mutexes?and?rw_locks?use?GCC?atomic?builtins
InnoDB:?The?first?specified?data?file?./ibdata1?did?not?exist:
InnoDB:?a?new?database?to?be?created!
100609?17:17:11??InnoDB:?Setting?file?./ibdata1?size?to?512?MB
InnoDB:?Database?physically?writes?the?file?full:?wait…
InnoDB:?Progress?in?MB:?100?200?300?400?500
100609?17:17:15??InnoDB:?Log?file?xxx/ib_logfile0?did?not?exist:?new?to?be?created
InnoDB:?Setting?log?file ?xxx/ib_logfile0?size?to?512?MB
InnoDB:?Database?physically?writes?the?file?full:?wait…
InnoDB:?Progress?in?MB:?100?200?300?400?500
100609?17:17:21??InnoDB:?Log?file?xxx/ib_logfile1?did?not?exist:?new?to?be?created
InnoDB:?Setting?log?file?xxxx/ib_logfile1?size?to?512?MB
InnoDB:?Database?physically?writes?the?file?full:?wait…
InnoDB:?Progress?in?MB:?100?200?300?400?500
InnoDB:?Doublewrite?buffer?not?found:?creating?new
InnoDB:?Doublewrite?buffer?created
InnoDB:?Creating?foreign?key?constraint?system?tables
InnoDB:?Foreign?key?constraint?system?tables?created
100609?17:17:26?InnoDB?Plugin?1.0.6-unknown?started;?log?sequence?number?0
100609?17:17:28?[Note]?Event?Scheduler:?Loaded?0?events
100609?17:17:28?[Note]?/usr/xtradb/libexec/mysqld:?ready?for?connections.
Version:?’5.1.45-log’??socket:?’xxx/mysqld.sock’??port:?4331??Source?distribution
InnoDB:?The?InnoDB?memory?heap?is?disabled
是因为使用了操作系统的内存分配器,所以就禁用了InnoDB的内置内存分配器
mysql>?show?variables?like?’%malloc%’;
+———————–+——-+
|?Variable_name?????????|?Value?|
+———————–+——-+
|?innodb_use_sys_malloc?|?ON????|
+———————–+——-+
1?row?in?set?(0.00?sec)
而在5.0里面执行是为空结果的，关于这个innodb_use_sys_malloc，具体可以参阅
Mutexes?and?rw_locks?use?GCC?atomic?builtins
对比以往的版本,InnoDB?Plugin?1.0.3之后的版本?使用了GCC?atomic?builtins来执行互斥和读写锁,性能会比以往使用的pthread_mutex_t要高效
参见?
InnoDB:?The?first?specified?data?file?./ibdata1?did?not?exist:
InnoDB:?a?new?database?to?be?created!
{dy}次启动mysql，因为默认的是innodb引擎，所以会自动创建一个test
InnoDB:?Doublewrite?buffer?not?found:?creating?new
InnoDB:?Doublewrite?buffer?created
什么是Doublewrite?
InnoDB将BP中的Dirty?Page刷（flush）到磁盘上时，首先会将Page刷到InnoDB?tablespace的一个区域中，我们称该区域为Double?write?Buffer。在向Double?write?Buffer写入成功后，再择机将数据拷贝到正在的数据文件对应的位置。
更多详细的信息可以看看performace?blog?的对
或者是苏普的对
参考资料
InnoDB?Plugin:?Enabling?GCC?atomic?built-in?functions?for?InnoDB?rw-locks
InnoDB?Plugin?1.0?for?MySQL?5.1?User’s?Guide
Innodb?Double?Write
转载烦请保留原文连接 http://dbahacker.com/mysql/innodb-plugin-log-analyze
