[DBCP-377] Dbcp Idle Check Mechanism Doesn't Work

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Cannot Reproduce
• Affects Version/s: 1.4

Environment

Linux mysql 5.1.4

• Assignee: Unassigned
• Reporter: yixin he
• Created: 05/Mar/12 14:02
• Updated: 31/May/14 04:02
• Resolved: 11/Jan/14 20:08

Description

Using :commons-dbcp-1.4.jar version

we use a distributed data access layer for Database Sharding with mysql
our web servers use mysql jdbc driver 1.5.4 to connect to this middleware layer with F5 between them for load balance.
the middleware layer will discard db links that idle for longger than 1 hour,and our dbcp configures to close links that idle for
longger than 30 minutes.

here we occurred exceptions as follows:

    java.net.SocketException
MESSAGE: Broken pipe

STACKTRACE:

java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2637)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1554)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)
        at com.mysql.jdbc.Connection.execSQL(Connection.java:3176)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1153)
        at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:794)
        ....
        at org.apache.commons.dbcp.DelegatingPreparedStatement.execute(DelegatingPreparedStatement.java:172)
        at org.apache.commons.dbcp.DelegatingPreparedStatement.execute(DelegatingPreparedStatement.java:172)

it seems that there are times when the links get from pool they have already been broken,we know that they are forcely closed by the middleware layer、but as dbcp idle check more frequently than the middleware layer(30m to 60m). How can this happen as the idle links
should have been closed by dbcp first. Are there any problems for the dbcp idle check Mechanism？

our dbcp configurations are as follows

    <property name="maxActive"><value>20</value></property>
    <property name="initialSize"><value>1</value></property>
    <property name="maxWait"><value>60000</value></property>
    <property name="maxIdle"><value>20</value></property>
    <property name="minIdle"><value>5</value></property>
    <property name="removeAbandoned"><value>true</value></property>
    <property name="removeAbandonedTimeout"><value>180</value></property>
    <property name="connectionProperties"><value>clientEncoding=GBK</value></property>
    <property name="timeBetweenEvictionRunsMillis"><value>60000</value></property>
    <property name="minEvictableIdleTimeMillis"><value>1800000</value></property>
    <property name="testWhileIdle"><value>true</value></property>
    <property name="testOnBorrow"><value>false</value></property>
    <property name="testOnReturn"><value>false</value></property>
    <property name="validationQuery"><value>SELECT @@SQL_MODE</value></property>
    <property name="numTestsPerEvictionRun"><value>32</value></property>