org.apache.drill.exec.work.foreman.rm

Class EmbeddedQueryQueue

java.lang.Object

org.apache.drill.exec.work.foreman.rm.EmbeddedQueryQueue

All Implemented Interfaces:

QueryQueue

public class EmbeddedQueryQueue
extends Object
implements QueryQueue

Query queue to be used in an embedded Drillbit. This queue has scope of only the one Drillbit (not even multiple Drillbits in the same process.) Primarily intended for testing, but may possibly be useful for other embedded applications.

Configuration is via config parameters (not via system options as for the distributed queue.)

drill.queue.embedded.enabled

Set to true to enable the embedded queue. But, this setting has effect only if the Drillbit is, in fact, embedded.

drill.queue.embedded.size

The number of active queries, all others queue. There is no upper limit on the number of queued entries.

drill.queue.embedded.timeout_ms

The maximum time a query will wait in the queue before failing.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	EmbeddedQueryQueue.EmbeddedQueueLease

Nested classes/interfaces inherited from interface org.apache.drill.exec.work.foreman.rm.QueryQueue

QueryQueue.QueryQueueException, QueryQueue.QueueLease, QueryQueue.QueueTimeoutException

Field Summary

Fields

Modifier and Type	Field and Description
static String	EMBEDDED_QUEUE
static String	ENABLED
static String	QUEUE_SIZE
static String	TIMEOUT_MS

Constructor Summary

Constructors

Constructor and Description
EmbeddedQueryQueue(DrillbitContext context)

Method Summary

Modifier and Type	Method and Description
void	close()
long	defaultQueryMemoryPerNode(double cost) Return the amount of memory per node when creating a EXPLAIN query plan.
boolean	enabled() Determine if the queue is enabled.
QueryQueue.QueueLease	enqueue(UserBitShared.QueryId queryId, double cost) Queue a query.
long	minimumOperatorMemory() Optional floor on the amount of memory assigned per operator.
void	setMemoryPerNode(long memoryPerNode)

Methods inherited from class java.lang.Object

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

Field Detail

EMBEDDED_QUEUE

public static String EMBEDDED_QUEUE

ENABLED

public static String ENABLED

QUEUE_SIZE

public static String QUEUE_SIZE

TIMEOUT_MS

public static String TIMEOUT_MS

Constructor Detail

EmbeddedQueryQueue

public EmbeddedQueryQueue(DrillbitContext context)

Method Detail

enabled

public boolean enabled()

Description copied from interface: QueryQueue

Determine if the queue is enabled.

Specified by:

enabled in interface QueryQueue

Returns:

true if the query is enabled, false otherwise.

setMemoryPerNode

public void setMemoryPerNode(long memoryPerNode)

Specified by:

setMemoryPerNode in interface QueryQueue

defaultQueryMemoryPerNode

public long defaultQueryMemoryPerNode(double cost)

Description copied from interface: QueryQueue

Return the amount of memory per node when creating a EXPLAIN query plan. Plans to be executed should get the query memory from the lease, as the lease may adjust the default amount on a per-query basis. This means that the memory used to execute the query may differ from the amount shown in an EXPLAIN plan.

Specified by:

defaultQueryMemoryPerNode in interface QueryQueue

Returns:

assumed memory per node, in bytes, to use when creating an EXPLAIN plan

enqueue

public QueryQueue.QueueLease enqueue(UserBitShared.QueryId queryId,
                                     double cost)
                              throws QueryQueue.QueueTimeoutException,
                                     QueryQueue.QueryQueueException

Description copied from interface: QueryQueue

Queue a query. The method returns only when the query is admitted for execution. As a result, the calling thread may block up to the configured wait time.

Specified by:

enqueue in interface QueryQueue

Parameters:

queryId - the query ID

cost - the cost of the query used for cost-based queueing

Returns:

the query lease which must be passed to #release(QueueLease) upon query completion

Throws:

QueryQueue.QueueTimeoutException - if the query times out waiting to be admitted.

QueryQueue.QueryQueueException - for any other error condition.

close

public void close()

Specified by:

close in interface QueryQueue

minimumOperatorMemory

public long minimumOperatorMemory()

Description copied from interface: QueryQueue

Optional floor on the amount of memory assigned per operator. This ensures that operators receive a certain amount, separate from any memory slicing. This can oversubscribe node memory if used incorrectly.

Specified by:

minimumOperatorMemory in interface QueryQueue

Returns:

minimum per-operator memory, in bytes