Ok, ho capito. Se l'esecuzione della pipeline di aggregazione supera il tempo espresso tramite il metodo maxTime a com.mongodb.MongoExecutionTimeoutException
viene lanciato.
Lo stacktrace dell'eccezione è esattamente il seguente:
com.mongodb.MongoExecutionTimeoutException: operation exceeded time limit
at com.mongodb.connection.ProtocolHelper.createSpecialException(ProtocolHelper.java:157)
at com.mongodb.connection.ProtocolHelper.getCommandFailureException(ProtocolHelper.java:111)
at com.mongodb.connection.CommandProtocol.execute(CommandProtocol.java:114)
at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:159)
at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:286)
at com.mongodb.connection.DefaultServerConnection.command(DefaultServerConnection.java:173)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:215)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:206)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:112)
at com.mongodb.operation.AggregateOperation$1.call(AggregateOperation.java:227)
at com.mongodb.operation.AggregateOperation$1.call(AggregateOperation.java:223)
at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:239)
at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:212)
at com.mongodb.operation.AggregateOperation.execute(AggregateOperation.java:223)
at com.mongodb.operation.AggregateOperation.execute(AggregateOperation.java:65)
at com.mongodb.Mongo.execute(Mongo.java:772)
at com.mongodb.Mongo$2.execute(Mongo.java:759)
Spero che aiuti.
