org.apache.lens.driver.es

Class ESDriver

java.lang.Object

org.apache.lens.server.api.driver.AbstractLensDriver

org.apache.lens.driver.es.ESDriver

All Implemented Interfaces:

Externalizable, Serializable, LensDriver

public class ESDriver
extends AbstractLensDriver

Driver for elastic search

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ESDriver()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	cancelQuery(QueryHandle handle) Cancel the execution of the query, specified by the handle.
void	close() Close the driver, releasing all resouces used up by the driver.
void	closePreparedQuery(QueryPrepareHandle handle) Close the prepare query specified by the prepared handle, releases all the resources held by the prepared query.
void	closeQuery(QueryHandle handle) Close the query specified by the handle, releases all the resources held by the query.
void	closeResultSet(QueryHandle handle) removing the result set as soon as the fetch is done
void	configure(org.apache.hadoop.conf.Configuration conf, String driverType, String driverName) Configure driver with Configuration passed.
QueryCost	estimate(AbstractQueryContext qctx) Estimate the cost of execution for given query.
LensResultSet	execute(QueryContext context) Elastic search does not have a concept of prepared query.
void	executeAsync(QueryContext context) Asynchronously execute the query.
DriverQueryPlan	explain(AbstractQueryContext context) Explain the given query.
DriverQueryPlan	explainAndPrepare(PreparedQueryContext pContext) Explain and prepare the given query.
LensResultSet	fetchResultSet(QueryContext context) Default implementation for fetchResultSet for all drivers.
org.apache.hadoop.conf.Configuration	getConf() Get driver configuration
com.google.common.collect.ImmutableSet<QueryLaunchingConstraint>	getQueryConstraints()
com.google.common.collect.ImmutableSet<WaitingQueriesSelectionPolicy>	getWaitingQuerySelectionPolicies()
void	prepare(PreparedQueryContext pContext) Prepare the given query.
void	readExternal(ObjectInput in) This flow could be abstracted out at the driver level
void	registerDriverEventListener(LensEventListener<DriverEvent> driverEventListener) Add a listener for driver events.
void	registerForCompletionNotification(QueryHandle handle, long timeoutMillis, QueryCompletionListener listener) Register for query completion notification.
void	updateStatus(QueryContext context) Update driver query status in the context object.
void	writeExternal(ObjectOutput out)

Methods inherited from class org.apache.lens.server.api.driver.AbstractLensDriver

decidePriority, getFullyQualifiedName, getQueryHook, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ESDriver

public ESDriver()

Method Detail

getConf

public org.apache.hadoop.conf.Configuration getConf()

Description copied from interface: LensDriver

Get driver configuration

estimate

public QueryCost estimate(AbstractQueryContext qctx)

Description copied from interface: LensDriver

Estimate the cost of execution for given query. This should be returned with very less latency - should return within 10s of milli seconds.

Parameters:

qctx - The query context

Returns:

The QueryCostTO object

explain

public DriverQueryPlan explain(AbstractQueryContext context)
                        throws LensException

Description copied from interface: LensDriver

Explain the given query.

Parameters:

context - The explain context

Returns:

The query plan object

Throws:

LensException - the lens exception

prepare

public void prepare(PreparedQueryContext pContext)
             throws LensException

Description copied from interface: LensDriver

Prepare the given query.

Parameters:

pContext - the context

Throws:

LensException - the lens exception

explainAndPrepare

public DriverQueryPlan explainAndPrepare(PreparedQueryContext pContext)
                                  throws LensException

Description copied from interface: LensDriver

Explain and prepare the given query.

Parameters:

pContext - the context

Returns:

The query plan object;

Throws:

LensException - the lens exception

closePreparedQuery

public void closePreparedQuery(QueryPrepareHandle handle)

Description copied from interface: LensDriver

Close the prepare query specified by the prepared handle, releases all the resources held by the prepared query.

Parameters:

handle - The query handle

execute

public LensResultSet execute(QueryContext context)
                      throws LensException

Elastic search does not have a concept of prepared query.

Parameters:

context - the context

Returns:

returns the result set, null if there is no result available

Throws:

LensException - the lens exception

executeAsync

public void executeAsync(QueryContext context)

Description copied from interface: LensDriver

Asynchronously execute the query.

Parameters:

context - The query context

registerForCompletionNotification

public void registerForCompletionNotification(QueryHandle handle,
                                     long timeoutMillis,
                                     QueryCompletionListener listener)

Description copied from interface: LensDriver

Register for query completion notification.

Parameters:

handle - the handle

timeoutMillis - the timeout millis

listener - the listener

updateStatus

public void updateStatus(QueryContext context)

Description copied from interface: LensDriver

Update driver query status in the context object.

Parameters:

context - The query context

fetchResultSet

public LensResultSet fetchResultSet(QueryContext context)
                             throws LensException

Description copied from class: AbstractLensDriver

Default implementation for fetchResultSet for all drivers. Should hold good in most cases. Note : If a driver is sticking to this default implementation, it should override AbstractLensDriver.createResultSet(QueryContext)

Specified by:

fetchResultSet in interface LensDriver

Overrides:

fetchResultSet in class AbstractLensDriver

Parameters:

context - The query context

Returns:

returns the result set

Throws:

LensException - the lens exception

closeResultSet

public void closeResultSet(QueryHandle handle)
                    throws LensException

removing the result set as soon as the fetch is done

Parameters:

handle - The query handle

Throws:

LensException - the lens exception

cancelQuery

public boolean cancelQuery(QueryHandle handle)
                    throws LensException

Description copied from interface: LensDriver

Cancel the execution of the query, specified by the handle.

Parameters:

handle - The query handle.

Returns:

true if cancel was successful, false otherwise

Throws:

LensException - the lens exception

closeQuery

public void closeQuery(QueryHandle handle)
                throws LensException

Description copied from interface: LensDriver

Close the query specified by the handle, releases all the resources held by the query.

Parameters:

handle - The query handle

Throws:

LensException - the lens exception

close

public void close()
           throws LensException

Description copied from interface: LensDriver

Close the driver, releasing all resouces used up by the driver.

Throws:

LensException - the lens exception

registerDriverEventListener

public void registerDriverEventListener(LensEventListener<DriverEvent> driverEventListener)

Description copied from interface: LensDriver

Add a listener for driver events.

Parameters:

driverEventListener - the driver event listener

getQueryConstraints

public com.google.common.collect.ImmutableSet<QueryLaunchingConstraint> getQueryConstraints()

Returns:

The QueryLaunchingConstraints to be checked before launching a query on driver. If there are no driver level constraints, then an empty set is returned. null is never returned.

getWaitingQuerySelectionPolicies

public com.google.common.collect.ImmutableSet<WaitingQueriesSelectionPolicy> getWaitingQuerySelectionPolicies()

Returns:

The WaitingQueriesSelectionPolicys to be used to select waiting queries eligible to be moved out of waiting state. If there are no driver level waiting query selection policies, then an empty set is returned. null is never returned.

configure

public void configure(org.apache.hadoop.conf.Configuration conf,
             String driverType,
             String driverName)
               throws LensException

Description copied from interface: LensDriver

Configure driver with Configuration passed.

Specified by:

configure in interface LensDriver

Overrides:

configure in class AbstractLensDriver

Parameters:

conf - The configuration object

driverType - Type of the driver (Example: hive, jdbc, el)

driverName - Name of this driver

Throws:

LensException - the lens exception

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

This flow could be abstracted out at the driver level

Throws:

IOException

ClassNotFoundException