question: public synchronized int checkExceptionThreshold ( String queueid ) { FetchItemQueue fiq = queues . get ( queueid ) ; if ( fiq == null ) { return 0 ; } if ( fiq . getQueueSize ( ) == 0 ) { return 0 ; } int excCount = fiq . incrementExceptionCounter ( ) ; if ( maxExceptionsPerQueue != - 1 && excCount >= maxExceptionsPerQueue ) { int deleted = fiq . emptyQueue ( ) ; LOG . info ( "* queue: " + queueid + " >> removed " + deleted + " URLs from queue because " + excCount + " exceptions occurred" ) ; for ( int i = 0 ; i < deleted ; i ++ ) { totalSize . decrementAndGet ( ) ; } return deleted ; } return 0 ; }
target:  Increment the exception counter of a queue in case of an exception e.g. timeout; when higher than a given threshold simply empty the queue.