I am assuming you use Jdk 1.6 and the jdbc-driver is jdbc 4.0 compliant. But it does not seem to support setClientInfo. GlassFish will try to set / reset client info for every getConnection(). Since the driver is throwing the exception, it is logged. If you are not using clientInfo, you can ignore the exception.
Related bug :
https://glassfish.dev.java.net/issues/show_bug.cgi?id=1766
Please check your driver vendor's documentation for connection.get/setClientInfo implementation/support.
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