HiKariCP数据库连接池

梦里梦外; 2022-05-16 03:26 263阅读 0赞

HiKariCP是[数据库][Link 1]连接池的一个后起之秀，号称性能最好，可以完美地PK掉其他连接池

官网：[https://github.com/brettwooldridge/HikariCP][https_github.com_brettwooldridge_HikariCP]

Java 8 maven artifact:

<dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
            <version>2.6.2</version>
        </dependency>

Java 9 Early Access maven artifact:

<dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP-java9ea</artifactId>
            <version>2.6.1</version>
        </dependency>

Java 7 maven artifact (maintenance mode):

<dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP-java7</artifactId>
            <version>2.4.12</version>
        </dependency>

Java 6 maven artifact (maintenance mode):

<dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP-java6</artifactId>
            <version>2.3.13</version>
        </dependency

### Initialization ###

You can use the `HikariConfig` class like so1:

HikariConfig config = new HikariConfig();
    config.setJdbcUrl("jdbc:mysql://localhost:3306/simpsons");
    config.setUsername("bart");
    config.setPassword("51mp50n");
    config.addDataSourceProperty("cachePrepStmts", "true");
    config.addDataSourceProperty("prepStmtCacheSize", "250");
    config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
    
    HikariDataSource ds = new HikariDataSource(config);

1 MySQL-specific example, do not copy verbatim.

or directly instantiate a `HikariDataSource` like so:

HikariDataSource ds = new HikariDataSource();
    ds.setJdbcUrl("jdbc:mysql://localhost:3306/simpsons");
    ds.setUsername("bart");
    ds.setPassword("51mp50n");
    ...

or property file based:

// Examines both filesystem and classpath for .properties file
    HikariConfig config = new HikariConfig("/some/path/hikari.properties");
    HikariDataSource ds = new HikariDataSource(config);

Example property file:

dataSourceClassName=org.postgresql.ds.PGSimpleDataSource
    dataSource.user=test
    dataSource.password=test
    dataSource.databaseName=mydb
    dataSource.portNumber=5432
    dataSource.serverName=localhost

or `java.util.Properties` based:

Properties props = new Properties();
    props.setProperty("dataSourceClassName", "org.postgresql.ds.PGSimpleDataSource");
    props.setProperty("dataSource.user", "test");
    props.setProperty("dataSource.password", "test");
    props.setProperty("dataSource.databaseName", "mydb");
    props.put("dataSource.logWriter", new PrintWriter(System.out));
    
    HikariConfig config = new HikariConfig(props);
    HikariDataSource ds = new HikariDataSource(config);

There is also a System property available, `hikaricp.configurationFile`, that can be used to specify the location of a properties file. If you intend to use this option, construct a `HikariConfig` or `HikariDataSource` instance using the default constructor and the properties file will be loaded.

Spring配置文件

``

`<bean id="dataSourceHikari" class="com.zaxxer.hikari.HikariDataSource"`

`destroy-method="shutdown">`

`<property name="driverClassName" value="${jdbc.driver}" />`

`<property name="jdbcUrl" value="${jdbc.url}" />`

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

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

``

`<property name="readOnly" value="false" />`

``

`<property name="connectionTimeout" value="30000" />`

``

`<property name="idleTimeout" value="600000" />`

`<!-- 一个连接的生命时长（毫秒），超时而且没被使用则被释放（retired），缺省:30分钟，建议设置比数据库超时时长少30秒，参考MySQL`

`wait_timeout参数（show variables like '%timeout%';） -->`

`<property name="maxLifetime" value="1800000" />`

``

`<property name="maximumPoolSize" value="60" />`

`<property name="minimumIdle" value="10" />`

`</bean>`

HikariCP所做的一些优化，总结如下：

>  *  字节码精简：优化代码，直到编译后的字节码最少，这样，CPU缓存可以加载更多的程序代码；
>  *  优化代理和拦截器：减少代码，例如HikariCP的Statement proxy只有100行代码，只有BoneCP的十分之一；
>  *  自定义数组类型（FastStatementList）代替ArrayList：避免每次get()调用都要进行range check，避免调用remove()时的从头到尾的扫描；
>  *  自定义集合类型（ConcurrentBag）：提高并发读写的效率；
>  *  其他针对BoneCP缺陷的优化，比如对于耗时超过一个CPU时间片的方法调用的研究（但没说具体怎么优化）。

[Link 1]: http://lib.csdn.net/base/mysql
[https_github.com_brettwooldridge_HikariCP]: https://github.com/brettwooldridge/HikariCP