Druid Connection Pool-Alibaba open source JDBC component

Druid in the field of connection pool can be said to be relatively fire, Alibaba open source of the JDBC connection pool, monitoring components, the following is a brief introduction to it.

It consists of three parts:

Druiddriver Agent driver, can provide the plug-in system based on Filter-chain mode.

Druiddatasource Efficient and manageable database connection pool.

Sqlparser.

function:

    . can monitor database access performance, the Druid built-in provides a powerful Statfilter plug-in to detail SQL performance, which is useful for online analysis of database access performance.

    . Replace DBCP and C3P0. Druid provides an efficient, powerful, scalable database connection pool.

    . Database password encryption. Writing the database password directly in the configuration file is bad behavior and can lead to security problems. Druiddruiver and Druiddatasource both support PasswordCallback.

    . SQL Execution Log, Druid provides different logfilter, can support common-logging, log4j and Jdklog, you can choose the corresponding logfilter as needed, monitor the database access you have applied.

    . to extend JDBC, if you want to have programming requirements for the JDBC layer, you can easily write the JDBC layer extensions through the Filter-chain mechanism provided by Druid.

properties are similar to the DBCP connection pool, but with filters monitoring (value stat), Add the following servlet to the Web.xml to see the example: http://localhost:8080/ benbeargame_test/. Druid with spring (as long as the configuration of initialsize,maxactive can), added in fact, the configuration performance is not good, the official document does not add other attributes

<!--data source Org.apache.commons.dbcp.BasicDataSource Com.alibaba.druid.pool.DruidDataSource-->
<bean id= "DataSource" class= "Com.alibaba.druid.pool.DruidDataSource" >
<property name= "Driverclassname" value= "Com.mysql.jdbc.Driver"/>
<property name= "url" value= "Jdbc:mysql://localhost/mybatis"/>
<property name= "username" value= "root"/>
<property name= "Password" value= "admin"/>

<!----> of Druid Connection pool
<property name= "Filters" value= "stat"/>

<!--below Druid and DBCP connection pool general ↓↓↓↓↓↓↓↓↓↓↓↓-->
<!--maxactive: Maximum number of connections-->
<property name= "maxactive" value= "/>"
<!--initialsize: Initializing connection-->
<property name= "InitialSize" value= "5"/>

</bean>

Filters Monitor Servlet
Http://localhost:8080/BenbearGame_test/druid
<servlet>
<servlet-name>DruidStatView<rvlet-name>
<servlet-class>com.alibaba.druid.support.http.StatViewServlet<rvlet-class>
<rvlet>
<servlet-mapping>
<servlet-name>DruidStatView<rvlet-name>
<url-pattern>/druid/*</url-pattern>
<rvlet-mapping>

http://blog.csdn.net/yunnysunny/article/details/8657095

Executecount	Current SQL execution times
Exectime	Current SQL Execution time
Execmax	Current SQL Maximum execution time
Txn	Number of transactions currently running
Error	Number of current SQL execution errors
Update	Number of rows already affected in the current SQL update or delete operation
Fetchrow	Number of rows that have been read in the current SQL operation
Running	Current number of SQL running
Concurrent	Current SQL maximum concurrent execution number
Exechisto	An array of time distributions for the current SQL execute operation	Divided into 0-1,1-10,10-100,100-1000,>1000,5 time distribution area, the unit is MS
Execrshisto	The current SQL does execute operation and resultset Open to Closed time sum distribution array	Ditto
Fetchrowhisto	Array of current SQL query time distributions	Ditto
Updatehisto	Current SQL update, delete time distribution array	Ditto

Configuration properties:

Configuration	Default value	Description
Name		The significance of configuring this property is that if there are multiple data sources, the monitoring can be distinguished by name. If not configured, a name will be generated, in the form: "datasource-" + system.identityhashcode (This)
Jdbcurl		The URL of the connection database, different databases. For example: Mysql:jdbc:mysql://10.20.153.104:3306/druid2 Oracle:jdbc:oracle:thin:@10.20.149.85:1521:ocnauto
Username		User name to connect to database
Password		The password to connect to the database. If you do not want the password to be written directly in the configuration file, you can use Configfilter. Look at this in detail: https://github.com/alibaba/druid/wiki/%E4%BD%BF%E7%94%A8ConfigFilter
Driverclassname	Automatic identification based on URL	This can not be matched, if not configured Druid will automatically identify the dbtype based on the URL, and then select the appropriate driverclassname
InitialSize	0	The number of physical connections that were established when the initialization was initiated. Initialization occurs when the display invokes the Init method, or when the first getconnection
Maxactive	8	Maximum number of connection pools
Maxidle	8	is no longer in use, configured and no effect
Minidle		Minimum number of connection pools
Maxwait		The maximum wait time, in milliseconds, to get the connection. When MAXWAIT is configured, the default is to enable fair locks, and concurrency is reduced, and if you need to, you can use an unfair lock by configuring the Useunfairlock property to True.
Poolpreparedstatements	False	Whether to cache PreparedStatement, i.e. Pscache. Pscache is a great boost to database performance for cursors, such as Oracle. It is recommended to close under MySQL.
Maxopenpreparedstatements	-1	To enable Pscache, you must configure greater than 0 and poolpreparedstatements automatically trigger the modification to true when greater than 0 o'clock. In Druid, there will be no problem of excessive memory usage under Oracle Pscache, which can be configured to be larger, such as 100
Validationquery		SQL that is used to detect the validity of a connection and requires a query statement. If Validationquery is Null,testonborrow, Testonreturn, Testwhileidle will not function.
Testonborrow	True	When requesting a connection, performing a validationquery detection connection is valid, and making this configuration can degrade performance.
Testonreturn	False	Performs a validationquery detection connection when returning a connection, and this configuration can degrade performance
Testwhileidle	False	The recommended configuration is true, does not affect performance, and guarantees security. When requesting a connection, detect if the idle time is greater than timebetweenevictionrunsmillis, perform validationquery detection connection is valid.
Timebetweenevictionrunsmillis		Has two meanings: 1 Destroy thread will detect the connection interval of 2) Testwhileidle judgment basis, detailed look at the description of Testwhileidle properties
Numtestsperevictionrun		No longer used, a druiddatasource only supports a evictionrun
Minevictableidletimemillis
Connectioninitsqls		The SQL that executes when the physical connection is initialized
Exceptionsorter	Automatic identification based on DBTYPE	Discard the connection when the database throws some unrecoverable exceptions
Filters		The property type is a string that configures the extension through an alias, and the common plug-ins are: FILTER:LOG4J Defense SQL injection Filter:wall for FILTER:STAT logs for monitoring statistics
Proxyfilters		The type is LIST<COM.ALIBABA.DRUID.FILTER.FILTER>, and if both filters and Proxyfilters are configured, it is a combinatorial relationship, not a replacement relationship