We are accessing a DB/2 Express database version 8.2 using the DB2 JDBC Driver. In some long running processes, we sometimes get an sql exception "A communication error has been detected".
Using the trace facility of the jdbc driver showed the error code -4499. In the db2 documentation for that error code I only found the following sentence: "A fatal error occurred that resulted in a disconnect.". Not very helpfull.

The complete informations from the trace file are:

[ibm][db2][jcc][Thread:main][SQLException@1ff0dde] java.sql.SQLException
[ibm][db2][jcc][Thread:main][SQLException@1ff0dde] SQL state = null
[ibm][db2][jcc][Thread:main][SQLException@1ff0dde] Error code = -4499
[ibm][db2][jcc][Thread:main][SQLException@1ff0dde] Message = A communication error has been detected. Communication protocol being used: UWReply.fill(). Communication API being used: recvBuff(). Location where the error was detected: ReasonCode=54. Communication function detecting the error: *. Protocol specific error codes(s) TCP/IP SOCKETS DB2ConnectionCorrelator: GA47E424.A30D.01A847092216
[ibm][db2][jcc][Thread:main][SQLException@1ff0dde] Stack trace follows
com.ibm.db2.jcc.a.DisconnectException: A communication error has been detected. Communication protocol being used: UWReply.fill(). Communication API being used: recvBuff(). Location where the error was detected: ReasonCode=54. Communication function detecting the error: *. Protocol specific error codes(s) TCP/IP SOCKETS DB2ConnectionCorrelator: GA47E424.A30D.01A847092216

In addition there is a stacktrace with the first 13 elements been inside the db2 jdbc driver.

Some more environment informations:
Client: Windows 2003 x86 using java 1.5.0
Database: DB2/AIX64, version SQL08025
JDBC Driver: IBM DB2 JDBC Universal Driver version 2.7.58

Does anyone know what can cause that error. Or even better, what can I do to solve that error.

Holger Schlegel

I have no idea, but have you tried applying the latest FixPak?

Since it is a "long running process" I suspect you are getting a TCP/IP timeout and the connection is being dropped.

Are you using any connection pooling software on the java client (JBoss, Webshpere, WebLogic, etc)?

The total process is running many hours (>10), but contains of many transactions. Some of them may contain heavy statements that may cause a timeout in the client.

If the connection is dropped by the client jdbc driver due to tcp/ip timeout, I expected to find a corresponging entry in the database log. But there is no such entry.

The java client uses a single connection, no connection pooling.

Holger Schlegel

The total process is running many hours (>10), but contains of many transactions. Some of them may contain heavy statements that may cause a timeout in the client.

If the connection is dropped by the client jdbc driver due to tcp/ip timeout, I expected to find a corresponging entry in the database log. But there is no such entry.

I just found out that the db2 jdbc driver has a property "loginTime" in seconds. It is used for login and for any sql request. After the set number of seconds, the driver closes the connection. Its default value of 0 is declared as "the default system timeout value".
Does anyone know where to find the concrete value for "default system timeout"?

Holger Schlegel

Since it's AIX, are you sure you have enough connection handlers?