THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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public class KafkaStreams implements AutoCloseable {
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/**
* Run an interactive query against a state store.
* <p>
* This method allows callers outside of the Streams runtime to
* access the internal state of stateful processors. See
* https://kafka.apache.org/documentation/streams/developer-guide/interactive-queries.html
* for more information.
* @throws StreamsNotStartedException If Streams has not yet been started. Just call {@link KafkaStreams#start()}
and then retry *this call.
* @throws StreamsStoppedException If Streams is in a terminal state like PENDING_SHUTDOWN, NOT_RUNNING, PENDING_ERROR, or ERROR. The caller should discover a new instance and then retry this callto query.
* @throws UnknownStateStoreException If the specified store name does not exist in the topology.
* @throws InvalidStateStorePartitionException If the specified partition does not exist.
* /
@Evolving
public <R> StateQueryResult<R> query(StateQueryRequest<R> request);
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@Evolving
public class QueryResult<R> {
// wraps a successful result
public static <R> QueryResult<R> forResult(R result);
// returns a failed query result because the store didn't know how to handle the query.
public static <R> QueryResult<R> forUnknownQueryType(Query<R> query, StateStore store);
// returns a failed query result because the partition wasn't caught up to the desired bound.
public static <R> QueryResult<R> notUpToBound(Position currentPosition, Position bound);
// Used by state stores that need to delegate to another store to run a query and then
// translate the results. Does not change the execution info or any other metadata.
public <NewR> QueryResult<NewR> swapResult(NewR newTypedResult);
// If requested, stores should record
// helpful information, such as their own class, how they executed the query,
// and the time they took.
public void addExecutionInfo(String executionInfo);
public boolean isSuccess();
public boolean isFailure();
public List<String> getExecutionInfo();
public FailureReason getFailureReason();
public String getFailure();
} |
FailureReason
An enum classifying failures for individual partitions' failures
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public enum FailureReason {
/**
* Failure indicating that the store doesn't know how to handle the given query.
*/
UNKNOWN_QUERY_TYPE,
/**
* Failure indicating that the store partition is not (yet) up to the desired bound.
* The caller should either try again later or try a different replica.
*/
NOT_UP_TO_BOUND,
/**
* Failure indicating that the requested store partition is not present on the local
* KafkaStreams instance. It may have been migrated to another instance during a rebalance.
* The caller is recommended to try a different replica.
*/
NOT_PRESENT,
/**
* The requested store partition does not exist at all. For example, partition 4 was requested,
* but the store in question only has 4 partitions (0 through 3).
*/
DOES_NOT_EXIST;
} |
Position
A class representing a processing state position in terms of its inputs: a vector or (topic, partition, offset) components.
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