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用户名:lulblog 笔名:lulblog 地区: 行业:其他 |
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wewe
(作者置顶)
| > | bloggerForBC -> jdbc:microsoft:sqlserver://10.10.4.190:2433;databaseName=blogger |
| URL | jdbc:microsoft:sqlserver://10.10.4.190:2433;databaseName=blogger |
| Driver | com.microsoft.jdbc.sqlserver.SQLServerDriver |
| Connections | 1 (min), 180 (max) |
| Prototyping | 10 |
| Connection Lifetime | 00:05:00 |
| Maximum active time | 00:01:00 |
| House keeping sleep time | 30s |
| House keeping test SQL | off |
| Fatal SQL exceptions | off |
| Wrapper | off |
| Statistics | 30s,15m |
| Start date | 30-??-2005 16:35:24 | |||
| Connections | 13 (active), 35 (available), 180 (max) | |||
| Served | 15651 | |||
| Refused | 0 | |||
| more information | ||||
| Served | 453 (15.10/s) | ||
| Refused | 0 (0.00/s) | ||
| Average active time | 0.26s | ||
| Activity level | 2% |
| Served | 8652 (15.05/s) | ||
| Refused | 0 (0.00/s) | ||
| Average active time | 0.48s | ||
| Activity level | 4% |
1
ab 测压
Google的启示
最近在对现有的搜索引擎进行分布式的改进, 回顾以前阅读过的 google file system 的文章时发现google的思维和我们平时固守的思维很不一样, 可以说很多在我们看来是有一些"偏激"的,可是正是由于这些偏激, 才导致google与其跟随者的不同.
以下为几个例子:
1. google认为, 所有的硬件都是容易产生故障的, 因此google认为故障是必然的, 不产生故障才是偶然现象. 这个想法和我们通常的意识是相反的.
2. Google认为, 一旦写入, 再也不删除和修改. 这点上google认为修改和删除会对系统造成潜在的伤害, 例如文件的不连续性, 文件定位的困难..
3. Google将Linux的 file system的block更改为 64M , 也就是说, 写文件的最小单元是64M, 而不是我们通常的512字节, 两者整整相差了128000倍.
4. Google认为修复是没有必要的, 当一个服务器出现问题的时候, 撤下来, 换上另外一个 google unit(google 单元)即可, 因为维修的成本远远大于直接上线一个全新的服务单元的成本. 说来容易, 其实只有当google结构真正实现高冗余和分布式这样的操作才可行, 而这些正是google的核心.
当我们设计一个系统的时候, 我们最简单的做法通常是会根据需求对已有的一些经验进行匹配, 这个过程中我们通常走的是近路,而且我们的经验常常会束缚我们的想法, 没有抛开经验进行全新的分析和设计, 也自然就难以有所创新.
er
| > | bloggerForBC -> jdbc:microsoft:sqlserver://10.10.4.190:2433;databaseName=blogger |
| URL | jdbc:microsoft:sqlserver://10.10.4.190:2433;databaseName=blogger |
| Driver | com.microsoft.jdbc.sqlserver.SQLServerDriver |
| Connections | 1 (min), 180 (max) |
| Prototyping | 10 |
| Connection Lifetime | 00:05:00 |
| Maximum active time | 00:01:00 |
| House keeping sleep time | 30s |
| House keeping test SQL | off |
| Fatal SQL exceptions | off |
| Wrapper | off |
| Statistics | 30s,15m |
| Start date | 30-??-2005 16:35:24 | |||
| Connections | 13 (active), 35 (available), 180 (max) | |||
| Served | 15651 | |||
| Refused | 0 | |||
| more information | ||||
| Served | 453 (15.10/s) | ||
| Refused | 0 (0.00/s) | ||
| Average active time | 0.26s | ||
| Activity level | 2% |
| Served | 8652 (15.05/s) | ||
| Refused | 0 (0.00/s) | ||
| Average active time | 0.48s | ||
| Activity level | 4% |
test34
| > | bloggerForBC -> jdbc:microsoft:sqlserver://10.10.4.190:2433;databaseName=blogger |
| URL | jdbc:microsoft:sqlserver://10.10.4.190:2433;databaseName=blogger |
| Driver | com.microsoft.jdbc.sqlserver.SQLServerDriver |
| Connections | 1 (min), 180 (max) |
| Prototyping | 10 |
| Connection Lifetime | 00:05:00 |
| Maximum active time | 00:01:00 |
| House keeping sleep time | 30s |
| House keeping test SQL | off |
| Fatal SQL exceptions | off |
| Wrapper | off |
| Statistics | 30s,15m |
| Start date | 30-??-2005 16:35:24 | |||
| Connections | 13 (active), 35 (available), 180 (max) | |||
| Served | 15651 | |||
| Refused | 0 | |||
| more information | ||||
| Served | 453 (15.10/s) | ||
| Refused | 0 (0.00/s) | ||
| Average active time | 0.26s | ||
| Activity level | 2% |
| Served | 8652 (15.05/s) | ||
| Refused | 0 (0.00/s) | ||
| Average active time | 0.48s | ||
| Activity level | 4% |