Re: PostgreSQL/Tomcat JNDI Datasource Questions

Hi,

You are using DBCP wich is a connection pool. The purpose of this
framework is to avoid closing connection right (for performance matters)?

/David

Warren Killian wrote:

> Hello group,
>
> I have several questions concerning configuring and using a JNDI
> DataSource
> with PostgreSQL and Apache Tomcat. Currently I have
> successfully configured a "basic" DataSource. Currently, my
> configuration
> which resides in a context.xml file is as follows:
>
> <Context className="org.apache.catalina.core.StandardContext"
> backgroundProcessorDelay="-1"
> cachingAllowed="true"
>
> charsetMapperClass="org.apache.catalina.util.CharsetMapper"
>
> configFile="/usr/local/jwsdp-1.3/conf/Catalina/localhost/test.xml"
> cookies="true"
> crossContext="false"
> debug="0"
> displayName="test"
> docBase="/usr/local/jwsdp-1.3/webapps/test"
> domain="Catalina"
> engineName="Catalina"
> j2EEApplication="none"
> j2EEServer="none"
> lazy="true"
> managerChecksFrequency="6"
> path="/test"
> privileged="false"
> reloadable="true"
> startupTime="8"
> swallowOutput="false"
> tldScanTime="0"
> useNaming="true"
> wrapperClass="org.apache.catalina.core.StandardWrapper">
>
> <Resource name="jdbc/test" scope="Shareable"
> type="javax.sql.DataSource"/>
> <ResourceParams name="jdbc/test">
> <parameter>
> <name>factory</name>
>
> <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
> </parameter>
> <parameter>
> <name>driverClassName</name>
> <value>org.postgresql.Driver</value>
> </parameter>
> <parameter>
> <name>url</name>
> <value>jdbc:postgresql://myIP/test</value>
> </parameter>
> <parameter>
> <name>username</name>
> <value>Whoopie</value>
> </parameter>
> <parameter>
> <name>password</name>
> <value>Doopie</value>
> </parameter>
> <parameter>
> <name>removeAbandoned</name>
> <value>true</value>
> </parameter>
> <parameter>
> <name>removeAbandonedTimeout</name>
> <value>20</value>
> </parameter>
> <parameter>
> <name>maxWait</name>
> <value>5000</value>
> </parameter>
> <parameter>
> <name>maxActive</name>
> <value>5</value>
> </parameter>
> <parameter>
> <name>maxIdle</name>
> <value>2</value>
> </parameter>
> <parameter>
> <name>validationQuery</name>
> <value>SELECT * FROM test</value>
> </parameter>
> </ResourceParams>
> </Context>
>
> Using the above configuration, my JSP pages can connect to PostgreSQL and
> perform all required database operations.
>
> But all is not right! I have the following issues:
>
> 1.) Connections are NEVER closed
> Say I hit my JSP page which perform a query and display the results.
> Using netstat I can see that one connection to PostgreSQL has been
> established. But then, if I uninstall and reinstall my web app and
> hit my
> JSP page again, then the output of "netstat -p -t" shows that a second
> connection to PostgreSQL is established. The first connection never
> goes away! If I continue to
> uninstall/reinstall/hit JSP page, the connections continue to acrue and
> never go away. The number of connections can even exceed the value of
> "maxActive" defined in my context.xml file. What am I doing wrong?
>
> 2.) Idle connections aren't closed
> As mentioned above, the connections which are opened by my web app are
> kept around forever and never closed. In my context.xml file above, I've
> defined the "removeAbandoned" parameter to true and have set the
> "removeAbandonedTimeout" parameter to 20 seconds. But the connections
> are
> never closed. Every time I run "netstat -p -t", the connections are
> still there. :(
>
> 3.) Is my configuration correct for performing Pooling?
> I "can" get "a" database connection using this configuration. But is
> this
> adequate to perform connection pooling? How can I tell if/when
> connection
> pooling is actually being performed correctly?
> Any help would be greatly appreciated.
>