Patch driver logfile has jdbc connection error

Issue:

adwork001.log has following errors:

Calling /d01apps/TS/10.1.3/appsutil/jdk/jre/bin/java ...
Exception in thread "main" java.sql.SQLException: The Network Adapter could not establish the connection
        at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
        at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:133)
        at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:199)
        at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:480)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:413)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:510)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:203)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:33)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:510)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at oracle.apps.ad.worker.AdJavaWorker.getAppsConnection(AdJavaWorker.java:1041)
        at oracle.apps.ad.worker.AdJavaWorker.main(AdJavaWorker.java:276)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
        at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:328)
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
        at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:328)
        at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:421)
        at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:630)
        at oracle.net.ns.NSProtocol.connect(NSProtocol.java:206)
        at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:966)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:292)
        ... 8 more
Caused by: java.net.ConnectException: Connection refused
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:352)
        at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:214)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:201)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:377)
        at java.net.Socket.connect(Socket.java:530)
        at oracle.net.nt.TcpNTAdapter.connect(TcpNTAdapter.java:120)
        at oracle.net.nt.ConnOption.connect(ConnOption.java:126)
        at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:306)
        ... 13 more

Cause:

jdbc connect string has wrong node entry. (Instead of DB hostname, the tnsentry has Apps tier hostname in the jdbc connect string)

Verification:

echo $APPS_JDBC_URL

verify "s_apps_jdbc_connect_descriptor" in $CONTEXT_FILE

Also verify, select node_name from fnd_nodes;

Solution:

If autoconfig is not run on DB Tier, bring down services, Run Autoconfig on DB Tier and then on APP Tier.

If Autoconfig is already ran on DB Tier, change the "s_apps_jdbc_connect_descriptor" parameter with connect DB host entry and run autoconfig in App node. Then resume the patch from where it stopped.