org.apache.lens.driver.hive

Class HiveDriver

java.lang.Object

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

org.apache.lens.driver.hive.HiveDriver

All Implemented Interfaces:

Externalizable, Serializable, LensDriver

public class HiveDriver
extends AbstractLensDriver

The Class HiveDriver.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_EXPIRY_DELAY
static String	HIVE_CONNECTION_CLASS The Constant HIVE_CONNECTION_CLASS.
static String	HS2_CALCULATE_PRIORITY
static String	HS2_CONNECTION_EXPIRY_DELAY The Constant HS2_CONNECTION_EXPIRY_DELAY.
static String	HS2_COST_CALCULATOR
static String	HS2_PRIORITY_DEFAULT_RANGES
static String	HS2_PRIORITY_RANGES Config param for defining priority ranges.
static String	SESSION_KEY_DELIMITER

Constructor Summary

Constructors

Constructor and Description
HiveDriver() Instantiates a new hive driver.

Method Summary

Modifier and Type	Method and Description
boolean	areDBResourcesAddedForSession(String sessionHandle, String database) Return true if resources have been added to this Hive session
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) Close the resultset for the query.
void	closeSession(LensSessionHandle sessionHandle) Close session.
void	configure(org.apache.hadoop.conf.Configuration conf, String driverType, String driverName) Configure driver with Configuration passed.
Priority	decidePriority(AbstractQueryContext ctx) decide priority based on query's cost.
QueryCost	estimate(AbstractQueryContext qctx) Estimate the cost of execution for given query.
LensResultSet	execute(QueryContext ctx) Blocking execute of the query
void	executeAsync(QueryContext ctx) Asynchronously execute the query.
HiveQueryPlan	explain(AbstractQueryContext explainCtx) Explain the given query.
DriverQueryPlan	explainAndPrepare(PreparedQueryContext pContext) Explain and prepare the given query.
Map<QueryHandle,org.apache.hive.service.cli.OperationHandle>	getHiveHandles() The hive handles.
boolean	hasLensSession(LensSessionHandle session) Checks for lens session.
void	prepare(PreparedQueryContext pContext) Prepare the given query.
void	readExternal(ObjectInput in)
void	registerDriverEventListener(LensEventListener<DriverEvent> driverEventListener) Add a listener for driver events.
void	registerForCompletionNotification(QueryContext context, long timeoutMillis, QueryCompletionListener listener) Register for query completion notification.
void	setResourcesAddedForSession(String sessionHandle, String database) Tell Hive driver that resources have been added for this session and for the given database
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

fetchResultSet, getConf, getFullyQualifiedName, getQueryConstraints, getQueryHook, getRetryPolicyDecider, getStatusUpdateMethod, getWaitingQuerySelectionPolicies, toString

Methods inherited from class java.lang.Object

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

Field Detail

HIVE_CONNECTION_CLASS

public static final String HIVE_CONNECTION_CLASS

The Constant HIVE_CONNECTION_CLASS.

See Also:

Constant Field Values

HS2_CONNECTION_EXPIRY_DELAY

public static final String HS2_CONNECTION_EXPIRY_DELAY

The Constant HS2_CONNECTION_EXPIRY_DELAY.

See Also:

Constant Field Values

HS2_CALCULATE_PRIORITY

public static final String HS2_CALCULATE_PRIORITY

See Also:

Constant Field Values

HS2_COST_CALCULATOR

public static final String HS2_COST_CALCULATOR

See Also:

Constant Field Values

HS2_PRIORITY_RANGES

public static final String HS2_PRIORITY_RANGES

Config param for defining priority ranges.

See Also:

Constant Field Values

DEFAULT_EXPIRY_DELAY

public static final long DEFAULT_EXPIRY_DELAY

See Also:

Constant Field Values

HS2_PRIORITY_DEFAULT_RANGES

public static final String HS2_PRIORITY_DEFAULT_RANGES

See Also:

Constant Field Values

SESSION_KEY_DELIMITER

public static final String SESSION_KEY_DELIMITER

See Also:

Constant Field Values

Constructor Detail

HiveDriver

public HiveDriver()
           throws LensException

Instantiates a new hive driver.

Throws:

LensException - the lens exception

Method Detail

areDBResourcesAddedForSession

public boolean areDBResourcesAddedForSession(String sessionHandle,
                                             String database)

Return true if resources have been added to this Hive session

Parameters:

sessionHandle - lens session identifier

database - lens database

Returns:

true if resources have been already added to this session + db pair

setResourcesAddedForSession

public void setResourcesAddedForSession(String sessionHandle,
                                        String database)

Tell Hive driver that resources have been added for this session and for the given database

Parameters:

sessionHandle - lens session identifier

database - lens database

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

estimate

public QueryCost estimate(AbstractQueryContext qctx)
                   throws LensException

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

Throws:

LensException - the lens exception if driver cannot estimate

explain

public HiveQueryPlan explain(AbstractQueryContext explainCtx)
                      throws LensException

Description copied from interface: LensDriver

Explain the given query.

Parameters:

explainCtx - The explain context

Returns:

The query plan object

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

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

closePreparedQuery

public void closePreparedQuery(QueryPrepareHandle handle)
                        throws LensException

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

Throws:

LensException - the lens exception

execute

public LensResultSet execute(QueryContext ctx)
                      throws LensException

Description copied from interface: LensDriver

Blocking execute of the query

The driver would be closing the driver handle, once the results are fetched.

Parameters:

ctx - the context

Returns:

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

Throws:

LensException - the lens exception

executeAsync

public void executeAsync(QueryContext ctx)
                  throws LensException

Description copied from interface: LensDriver

Asynchronously execute the query.

Parameters:

ctx - The query context

Throws:

LensException - the lens exception

updateStatus

public void updateStatus(QueryContext context)
                  throws LensException

Description copied from interface: LensDriver

Update driver query status in the context object.

Parameters:

context - The query context

Throws:

LensException - the lens exception

closeResultSet

public void closeResultSet(QueryHandle handle)
                    throws LensException

Description copied from interface: LensDriver

Close the resultset for the query. Closing an already closed resultset should not result in failures.

Parameters:

handle - The query handle

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

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

close

public void close()

Description copied from interface: LensDriver

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

registerDriverEventListener

public void registerDriverEventListener(LensEventListener<DriverEvent> driverEventListener)

Add a listener for driver events.

Parameters:

driverEventListener - the driver event listener

decidePriority

public Priority decidePriority(AbstractQueryContext ctx)

Description copied from interface: LensDriver

decide priority based on query's cost. The cost should be already computed by estimate call, but it's not guaranteed to be pre-computed. It's up to the driver to do an on-demand computation of cost.

Specified by:

decidePriority in interface LensDriver

Overrides:

decidePriority in class AbstractLensDriver

Parameters:

ctx - Query context whose priority is to be decided

registerForCompletionNotification

public void registerForCompletionNotification(QueryContext context,
                                              long timeoutMillis,
                                              QueryCompletionListener listener)

Description copied from interface: LensDriver

Register for query completion notification.

Specified by:

registerForCompletionNotification in interface LensDriver

Overrides:

registerForCompletionNotification in class AbstractLensDriver

Parameters:

context - the context

timeoutMillis - the timeout millis

listener - the listener. Only query completions are guaranteed to be notified. Notably: SUCCESS and FAILURE

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Throws:

IOException

closeSession

public void closeSession(LensSessionHandle sessionHandle)

Close session.

Parameters:

sessionHandle - the session handle

hasLensSession

public boolean hasLensSession(LensSessionHandle session)

Checks for lens session.

Parameters:

session - the session

Returns:

true, if successful

getHiveHandles

@Generated(value="lombok")
public Map<QueryHandle,org.apache.hive.service.cli.OperationHandle> getHiveHandles()

The hive handles.