org.apache.drill.exec.work.foreman

Class Foreman

java.lang.Object

org.apache.drill.exec.work.foreman.Foreman

All Implemented Interfaces:

Runnable

public class Foreman
extends Object
implements Runnable

Foreman manages all the fragments (local and remote) for a single query where this is the driving/root node. The flow is as follows:

• Foreman is submitted as a runnable.
• Runnable does query planning.
• state changes from PENDING to RUNNING
• Runnable sends out starting fragments
• Status listener are activated
• The Runnable's run() completes, but the Foreman stays around
• Foreman listens for state change messages.
• state change messages can drive the state to FAILED or CANCELED, in which case messages are sent to running fragments to terminate
• when all fragments complete, state change messages drive the state to COMPLETED

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Foreman.PhysicalFromLogicalExplain
static class	Foreman.ProfileOption

Constructor Summary

Constructors

Constructor and Description
Foreman(WorkManager.WorkerBee bee, DrillbitContext drillbitContext, UserClientConnection connection, UserBitShared.QueryId queryId, UserProtos.RunQuery queryRequest) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	addToEventQueue(UserBitShared.QueryResult.QueryState newState, Exception exception) Tells the foreman to move to a new state. This will be added to the end of the event queue and will be processed once the foreman is ready to accept external events.
void	cancel() Cancel the query.
QueryContext	getQueryContext() Get the QueryContext created for the query.
UserBitShared.QueryId	getQueryId()
QueryManager	getQueryManager() Get the QueryManager created for the query.
String	getQueryText()
UserBitShared.QueryResult.QueryState	getState()
void	resume() Resume the query.
void	run() Called by execution pool to do query setup, and kick off remote execution.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Foreman

public Foreman(WorkManager.WorkerBee bee,
       DrillbitContext drillbitContext,
       UserClientConnection connection,
       UserBitShared.QueryId queryId,
       UserProtos.RunQuery queryRequest)

Constructor. Sets up the Foreman, but does not initiate any execution.

Parameters:

bee - used to submit additional work

drillbitContext -

connection -

queryId - the id for the query

queryRequest - the query to execute

Method Detail

getQueryContext

public QueryContext getQueryContext()

Get the QueryContext created for the query.

Returns:

the QueryContext

getQueryManager

public QueryManager getQueryManager()

Get the QueryManager created for the query.

Returns:

the QueryManager

cancel

public void cancel()

Cancel the query. Asynchronous -- it may take some time for all remote fragments to be terminated.

resume

public void resume()

Resume the query. Regardless of the current state, this method sends a resume signal to all fragments. This method can be called multiple times.

run

public void run()

Called by execution pool to do query setup, and kick off remote execution.

Note that completion of this function is not the end of the Foreman's role in the query's lifecycle.

Specified by:

run in interface Runnable

addToEventQueue

public void addToEventQueue(UserBitShared.QueryResult.QueryState newState,
                   Exception exception)

Tells the foreman to move to a new state.
This will be added to the end of the event queue and will be processed once the foreman is ready to accept external events.

Parameters:

newState - the state to move to

exception - if not null, the exception that drove this state transition (usually a failure)

getQueryId

public UserBitShared.QueryId getQueryId()

getState

public UserBitShared.QueryResult.QueryState getState()

getQueryText

public String getQueryText()

Returns:

sql query text of the query request