Oracle DB connections not releasing from connection pool in Tomcat 8

[Raja Karunanidi]

We are migrating Tomcat6, java 6 and Oracle 10g web-applications to Tomcat 8, Java 8 and Oracle 10g. Our applications working fine after migrated, but initial connections (initialSize="5") available in connection pool not released after Tomcat shut down. When second time starting tomcat, its creating 5 more initial connections to pool. I am using below resource configuration in server.xml

<Resource name="TestAppDataSource" auth="Container"
    factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
    type="javax.sql.DataSource" driverClassName="oracle.jdbc.OracleDriver"
    initialSize="5" maxActive="40" maxIdle="40" minIdle="5"
    timeBetweenEvictionRunsMillis="30000" minEvictableIdleTimeMillis="30000"
    maxWait="10000" testWhileIdle="true" testOnBorrow="true" testOnReturn="false"
    validationQuery="SELECT 1 from dual" validationInterval="30000" 
    logAbandoned="true" removeAbandonedTimeout="30"
    removeAbandonedOnBorrow="true" removeAbandonedOnMaintenance="true"
    suspectTimeout="300" maxAge="60000"
    url="jdbc:oracle:thin:@//IP_ADDRESS:1521/SCHEMA_NAME"
    username="USER_NAME" password="PASSWORD"
/>

And below resource link configuration in application META_INF/context.xml

<ResourceLink
    name="APP_TEST" global="TestAppDataSource" 
    type="javax.sql.DataSource"
/>

I am using ojdbc7.jar for oracle driver. Please help whether i missed any configuration..

[A.J. Côté]

Are you aware of so_linger?

Are you sure this didn't occur before and how do you tell tomcat really keeps database connections open? Perspective is important here,,,

Did you switch OS as well when migrating to tomcat?

When the above are checked; tomcat has to tell the pool to release resources somehow when it shuts down. Please check the above issues first although.

http://wiki.treck.com/Socket_Options
https://msdn.microsoft.com/en-us/library/windows/desktop/ms738547%28v=vs.85%29.aspx
https://stackoverflow.com/questions/3757289/tcp-option-so-linger-zero-when-its-required
etc...

[Raja Karunanidi]

A.J. Côté wrote:Are you aware of so_linger?

Are you sure this didn't occur before and how do you tell tomcat really keeps database connections open? Perspective is important here,,,

Did you switch OS as well when migrating to tomcat?

When the above are checked; tomcat has to tell the pool to release resources somehow when it shuts down. Please check the above issues first although.

http://wiki.treck.com/Socket_Options
https://msdn.microsoft.com/en-us/library/windows/desktop/ms738547%28v=vs.85%29.aspx
https://stackoverflow.com/questions/3757289/tcp-option-so-linger-zero-when-its-required
etc...

Thanks for your reply Mr.Côté.
I checked connection pool releasing its initial connection (initialSize=5) in Tomcat 6 shutdown through oracle DB v$session table. But its not happening on Tomcat 8 and Java 8. For more verification i tried below combinations:
Tomcat 6 & Java 6 - Connections Releasing - Working fine
Tomcat 6 & Java 8 - Connections Releasing - Working fine
Tomcat 8 & Java 6 - Connections Not releasing
Tomcat 8 & Java 8 - Connections Not releasing
Whether i missed any configurations for Tomcat 8 or have to use any special oracle driver jar??