com.bigdata.bop.engine

Interface IQueryPeer

All Superinterfaces:

Remote

All Known Subinterfaces:

IQueryClient

All Known Implementing Classes:

FederatedQueryEngine, QueryEngine

public interface IQueryPeer
extends Remote

Interface for a node participating in the exchange of NIO buffers to support query execution.

Method Summary

Methods

Modifier and Type	Method and Description
void	bufferReady(IChunkMessage<IBindingSet> msg) Notify a service that a buffer having data for some BOp in some running query is available.
void	cancelQuery(UUID queryId, Throwable cause) Notify a service that the query has been terminated.
void	declareQuery(IQueryDecl queryDecl) Deprecated. This method is unused and will probably disappear. The nodes in a cluster reach back to the query controller using IQueryClient.getQuery(UUID) to resolve the query on its first reference. This is handled by the FederatedQueryEngine within its run() loop where it accepts IChunkMessages.
UUID	getServiceUUID() The UUID of the service in which this QueryEngine is running.

Method Detail

getServiceUUID

UUID getServiceUUID()
                    throws RemoteException

The UUID of the service in which this QueryEngine is running.

Returns:

The UUID of the service in which this QueryEngine is running -or- a unique and distinct UUID if the QueryEngine is not running against an IBigdataFederation.

Throws:

RemoteException

See Also:

IService.getServiceUUID()

declareQuery

void declareQuery(IQueryDecl queryDecl)
                  throws RemoteException

Deprecated. This method is unused and will probably disappear. The nodes in a cluster reach back to the query controller using IQueryClient.getQuery(UUID) to resolve the query on its first reference. This is handled by the FederatedQueryEngine within its run() loop where it accepts IChunkMessages.

Declare a query to a peer. This message is sent to the peer before any other message for that query and declares the query and the query controller with which the peer must communicate during query evaluation.

Parameters:

queryDecl - The query declaration.

Throws:

UnsupportedOperationException - unless running in scale-out.

RemoteException

bufferReady

void bufferReady(IChunkMessage<IBindingSet> msg)
                 throws RemoteException

Notify a service that a buffer having data for some BOp in some running query is available. The receiver may request the data when they are ready. If the query is cancelled, then the sender will drop the buffer.

Parameters:

msg - The message.

Throws:

UnsupportedOperationException - unless running in scale-out.

RemoteException

cancelQuery

void cancelQuery(UUID queryId,
               Throwable cause)
                 throws RemoteException

Notify a service that the query has been terminated. The peer MUST NOT cancel the query synchronously as that can lead to a deadlock with the query controller. Instead, the peer should queue a task to cancel the query and then return.

Parameters:

queryId - The query identifier.

cause - The cause. When null, this is presumed to be normal query termination.

Throws:

RemoteException