Alibaba connection pool druid configuration details

A large part of the Java program needs to operate the database . In order to improve the performance, when operating the database, the database connection pool has to be used. There are many choices for database connection pools, such as c3p, dhcp, proxool, etc. Druid, as a rising star, has gradually entered everyone's attention with its excellent performance. Next, this tutorial will talk about the simple use of druid.

First download the latest jar package from http://repo1.maven.org/maven2/com/alibaba/druid/ . If you want to compile with the latest source code, you can download the source code from https://github.com/alibaba/druid , and then use the maven command line, or import it into eclipse for compilation.

Similar to dbcp, the configuration items of druid are as follows

configure	Default value	illustrate
name		The significance of configuring this property is that if there are multiple data sources, they can be distinguished by name when monitoring. If not configured, a name will be generated in the format: "DataSource-" + System.identityHashCode(this)
jdbcUrl		The url to connect to the database is different for different databases. For example: mysql : jdbc:mysql://10.20.153.104:3306/druid2 oracle : jdbc:oracle:thin:@10.20.149.85:1521:ocnauto
username		Username to connect to the database
password		Password to connect to the database. If you don't want the password to be written directly in the configuration file, you can use ConfigFilter. See here for details: https://github.com/alibaba/druid/wiki/%E4%BD%BF%E7%94%A8ConfigFilter
driverClassName	Automatically identify by url	This item can be matched or not. If druid is not configured, the dbType will be automatically recognized according to the url, and then the corresponding driverClassName will be selected.
initialSize	0	The number of physical connections established during initialization. Initialization occurs when the init method is explicitly called, or the first time getConnection
maxActive	8	Maximum number of connection pools
maxIdle	8	It is no longer used, and the configuration has no effect
minIdle		Minimum number of connection pools
maxWait		The maximum wait time when getting a connection, in milliseconds. After maxWait is configured, fair locks are enabled by default, and the concurrency efficiency will decrease. If necessary, you can use unfair locks by configuring the useUnfairLock property to true.
halfPreparedStatements	false	Whether to cache preparedStatement, which is PSCache. PSCache greatly improves the performance of databases that support cursors, such as oracle. There is no PSCache function in versions below mysql5.5, it is recommended to close it. The author used PSCache in version 5.5, and found that PSCache has a cache hit rate record through the monitoring interface, which should support PSCache.
maxOpenPreparedStatements	-1	To enable PSCache, it must be configured with a value greater than 0. When greater than 0, poolPreparedStatements is automatically triggered and modified to true. In Druid, there is no problem that PSCache under Oracle occupies too much memory, you can configure this value to be larger, such as 100
validationQuery		The sql used to detect whether the connection is valid requires a query statement. If the validationQuery is null, testOnBorrow, testOnReturn, testWhileIdle will not work.
testOnBorrow	true	When applying for a connection, execute the validationQuery to check whether the connection is valid. This configuration will reduce performance.
testOnReturn	false	When returning the connection, execute the validationQuery to check whether the connection is valid. This configuration will reduce performance.
testWhileIdle	false	It is recommended to configure it to true, which does not affect performance and ensures security. Detect when applying for a connection. If the idle time is greater than timeBetweenEvictionRunsMillis, execute validationQuery to check whether the connection is valid.
timeBetweenEvictionRunsMillis		There are two meanings: 1) The Destroy thread will detect the connection interval 2) The judgment basis of testWhileIdle, see the description of the testWhileIdle property for details
numTestsPerEvictionRun		No longer used, a DruidDataSource only supports one EvictionRun
minEvictableIdleTimeMillis
connectionInitSqls		The sql executed when the physical connection is initialized
exceptionSorter	根据dbType自动识别	当数据库抛出一些不可恢复的异常时，抛弃连接
filters		属性类型是字符串，通过别名的方式配置扩展插件，常用的插件有：监控统计用的filter:stat 日志用的filter:log4j 防御sql注入的filter:wall
proxyFilters		类型是List<com.alibaba.druid.filter.Filter>，如果同时配置了filters和proxyFilters，是组合关系，并非替换关系

表1.1 配置属性

加入 druid-1.0.9.jar

ApplicationContext.xml

< bean name = "transactionManager" class ="org.springframework.jdbc.datasource.DataSourceTransactionManager" >

< property name = "dataSource" ref = "dataSource" ></ property >

</ bean >

< bean id = "propertyConfigurer" class ="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" >

< property name = "locations" >

< list >

< value > /WEB-INF/classes/dbconfig.properties </ value >

</ list >

</ property >

</ bean >

< bean id = "dataSource" class = "com.alibaba.druid.pool.DruidDataSource"destroy-method = "close" >

< property name = "url" value = "${url}" />

< property name = "username" value = "${username}" />

< property name = "password" value = "${password}" />

< property name = "driverClassName" value = "${driverClassName}" />

< property name = "filters" value = "${filters}" />

< property name = "maxActive" value = "${maxActive}" />

< property name = "initialSize" value = "${initialSize}" />

< property name = "maxWait" value = "${maxWait}" />

< property name = "minIdle" value = "${minIdle}" />

< property name = "timeBetweenEvictionRunsMillis" value ="${timeBetweenEvictionRunsMillis}" />

< property name = "minEvictableIdleTimeMillis" value ="${minEvictableIdleTimeMillis}" />

< property name = "validationQuery" value = "${validationQuery}" />

< property name = "testWhileIdle" value = "${testWhileIdle}" />

< property name = "testOnBorrow" value = "${testOnBorrow}" />

< property name = "testOnReturn" value = "${testOnReturn}" />

< property name = "maxOpenPreparedStatements" value ="${maxOpenPreparedStatements}" />

< property name = "removeAbandoned" value = "${removeAbandoned}" />

< property name = "removeAbandonedTimeout" value ="${removeAbandonedTimeout}" />

< property name = "logAbandoned" value = "${logAbandoned}" />

</ bean >

dbconfig.properties

url: jdbc:MySQL:// localhost :3306/ newm

driverClassName: com.mysql.jdbc.Driver

username: root

password: root

filters: stat

maxActive: 20

initialSize: 1

maxWait: 60000

minIdle: 10

maxIdle: 15

timeBetweenEvictionRunsMillis: 60000

minEvictableIdleTimeMillis: 300000

validationQuery: SELECT 'x'

testWhileIdle: true

testOnBorrow: false

testOnReturn: false

maxOpenPreparedStatements: 20

removeAbandoned: true

removeAbandonedTimeout: 1800

logAbandoned: true

web.xml

< filter >

< filter-name > DruidWebStatFilter </ filter-name >

< filter-class > com.alibaba.druid.support.http.WebStatFilter </ filter-class >

< init-param >

< param-name > exclusions </ param-name >

< param-value > *. js ,*. gif ,*. jpg ,*. png ,*. css ,*. ico ,/ druid /* </ param-value >

</ init-param >

</ filter >

< filter-mapping >

< filter-name > DruidWebStatFilter </ filter-name >

< url-pattern > /* </ url-pattern >

</ filter-mapping >

< servlet >

< servlet-name > DruidStatView </ servlet-name >

< servlet-class > com.alibaba.druid.support.http.StatViewServlet </ servlet-class >

</ servlet >

< servlet-mapping >

< servlet-name > DruidStatView </ servlet-name >

< url-pattern > / druid /* </ url-pattern >

</ servlet-mapping >

Visit the monitoring page: http://ip:port/projectName/druid/index.html

Alibaba connection pool druid configuration details

表1.1 配置属性

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