Java OracleDB connection taking too long the first time

Question

I'm having a problem when connecting to an Oracle database, it takes a long time (about ~5 minutes) and it sends the below shown exception. Most of the time, after the first error, the next connections for the same process work correctly.

It is a RHEL 6 machine, with two different network interfaces and ip addresses.

NOTE: I am not using an url like: "jdbc:oracle:thin:@xxxx:yyy, it is actually: "jdbc:oracle:thin:@xxxx:yyyy:zzz. The SID is not missing, sorry for that :(

This is roughly what I've isolated:

bin/java -classpath ojdbc6_g.jar -Djavax.net.debug=all -Djava.util.logging.config.file=logging.properties

Class.forName ("oracle.jdbc.OracleDriver")
DriverManager.getConnection("jdbc:oracle:thin:@xxxx:yyyy", "aaaa", "bbbb")

Error StackTrace:

java.sql.SQLRecoverableException: IO Error: Connection reset
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:533)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:557)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:233)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:29)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:556)
        at java.sql.DriverManager.getConnection(DriverManager.java:579)
        at java.sql.DriverManager.getConnection(DriverManager.java:221)
        at test.jdbc.Main(Test.java:120)
Caused by: java.net.SocketException: Connection reset
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
        at oracle.net.ns.DataPacket.send(DataPacket.java:248)
        at oracle.net.ns.NetOutputStream.flush(NetOutputStream.java:227)
        at oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:309)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:257)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:182)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:99)
        at oracle.jdbc.driver.T4CSocketInputStreamWrapper.readNextPacket(T4CSocketInputStreamWrapper.java:121)
        at oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:77)
        at oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:1173)
        at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:309)
        at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:200)
        at oracle.jdbc.driver.T4CTTIoauthenticate.doOSESSKEY(T4CTTIoauthenticate.java:404)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:430)
        ... 35 more

There's a very verbose log of what happens over here: http://pastebin.com/MMFKU26z The line that says GET STUCK HERE represents the 5 minute waiting time

Answer 1

You are probably running into an issue with the Oracle JDBC driver which uses a blocking random number generator by default on Linux. Try running Java with the following argument:

-Djava.security.egd=file:/dev/./urandom

Alternatively you could start up a daemon to feed the random number generator. The Linux "rngd" daemon is an example.

Sources:

• http://www.usn-it.de/index.php/2009/02/20/oracle-11g-jdbc-driver-hangs-blocked-by-devrandom-entropy-pool-empty/
• http://bugs.java.com/view_bug.do;?bug_id=6521844
• https://bugs.openjdk.java.net/browse/JDK-6202721
• https://community.oracle.com/message/3701989
• Oracle JDBC intermittent Connection Issue
• Oracle getConnection slow
• How to solve performance problem with Java SecureRandom?