Sometimes graph, that cooperates with MySQL database (DBInputTable, DBJoin, DBLookupTable) hangs up. There is no error, but graph is still running and the number of processed records doesn’t change. What can be the cause?
The reason is the bug in MySQL jdbc driver (http://bugs.mysql.com/bug.php?id=31353). To avoid the never-ending graph execution set socketTimeout connection property. Then the graph will fail, but it won’t run “forever”.