com.datastax.driver.core

Class ExecutionInfo

java.lang.Object

com.datastax.driver.core.ExecutionInfo

public class ExecutionInfo
extends Object

Basic information on the execution of a query.

Method Summary

Modifier and Type	Method and Description
ConsistencyLevel	getAchievedConsistencyLevel() If the query returned without achieving the requested consistency level due to the RetryPolicy, this return the biggest consistency level that has been actually achieved by the query.
PagingState	getPagingState() The paging state of the query.
byte[]	getPagingStateUnsafe() Returns the "raw" paging state of the query.
Host	getQueriedHost() Return the Cassandra host that coordinated this query.
QueryTrace	getQueryTrace() The query trace if tracing was enabled on this query.
List<Host>	getTriedHosts() The list of tried hosts for this query.
boolean	isSchemaInAgreement() Whether the cluster had reached schema agreement after the execution of this query.

Methods inherited from class java.lang.Object

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

Method Detail

getTriedHosts

public List<Host> getTriedHosts()

The list of tried hosts for this query.

In general, this will be a singleton list with the host that coordinated that query. However:

• if a host is tried by the driver but is dead or in error, that host is recorded and the query is retried;
• on a timeout or unavailable exception, some RetryPolicy may retry the query on the same host, so the same host might appear twice.
• if speculative executions are enabled, other hosts might have been tried speculatively as well.

If you are only interested in fetching the final (and often only) node coordinating the query, getQueriedHost() provides a shortcut to fetch the last element of the list returned by this method.

Returns:

the list of tried hosts for this query, in the order tried.

getQueriedHost

public Host getQueriedHost()

Return the Cassandra host that coordinated this query.

This is a shortcut for getTriedHosts().get(getTriedHosts().size()).

Returns:

return the Cassandra host that coordinated this query.

getAchievedConsistencyLevel

public ConsistencyLevel getAchievedConsistencyLevel()

If the query returned without achieving the requested consistency level due to the RetryPolicy, this return the biggest consistency level that has been actually achieved by the query.

Note that the default RetryPolicy (DefaultRetryPolicy) will never allow a query to be successful without achieving the initially requested consistency level and hence with that default policy, this method will always return null. However, it might occasionally return a non-null with say, DowngradingConsistencyRetryPolicy.

Returns:

null if the original consistency level of the query was achieved, or the consistency level that was ultimately achieved if the RetryPolicy triggered a retry at a different consistency level than the original one.

getQueryTrace

public QueryTrace getQueryTrace()

The query trace if tracing was enabled on this query.

Returns:

the QueryTrace object for this query if tracing was enable for this query, or null otherwise.

getPagingState

public PagingState getPagingState()

The paging state of the query.

This object represents the next page to be fetched if this query is multi page. It can be saved and reused later on the same statement.

Returns:

the paging state or null if there is no next page.

See Also:

Statement.setPagingState(PagingState)

getPagingStateUnsafe

public byte[] getPagingStateUnsafe()

Returns the "raw" paging state of the query.

Contrary to getPagingState(), there will be no validation when this is later reinjected into a statement.

Returns:

the paging state or null if there is no next page.

See Also:

Statement.setPagingStateUnsafe(byte[])

isSchemaInAgreement

public boolean isSchemaInAgreement()

Whether the cluster had reached schema agreement after the execution of this query.

After a successful schema-altering query (ex: creating a table), the driver will check if the cluster's nodes agree on the new schema version. If not, it will keep retrying for a given delay (configurable via Cluster.Builder.withMaxSchemaAgreementWaitSeconds(int)).

If this method returns false, clients can call Metadata.checkSchemaAgreement() later to perform the check manually.

Note that the schema agreement check is only performed for schema-altering queries For other query types, this method will always return true.

Returns:

whether the cluster reached schema agreement, or true for a non schema-altering statement.