THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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Public Interfaces:
- Adding new Class class
StoreQueryParams
.java to provide user options to theQueryableStoreProvider
layer layer to understand what kind of stores a user wants. It would currently include whether a user is okay with serving stale data and if user already knows what is the partition of the store a user is looking at. Since store name and partition would be a unique combination, a taskId can be generated from this information to return the store for that particular task.
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package org.apache.kafka.streams; //** * Represents all the query options that a user can provide to state what kind of stores it is expecting. The options would be whether a user would want to enable/disable stale stores* or whether it knows the list of partitions that it specifically wants to fetch. If this information is not provided the default behavior is to fetch the stores for all the partitions available on that instance* for that particular store name. * It contains a partition, which for a point queries can be populated from the KeyQueryMetadata. */ public class StoreQueryParams<T> { private Integer partition; private boolean staleStores; private final String storeName; private final QueryableStoreType<T> queryableStoreType; private StoreQueryParams(final String storeName, final QueryableStoreType<T> queryableStoreType) { this.storeName = storeName; this.queryableStoreType = queryableStoreType; } public static <T> StoreQueryParams<T> fromNameAndType(final String storeName, final QueryableStoreType<T> queryableStoreType) { return new <T> StoreQueryParams<T>(storeName, queryableStoreType); } /** * Get the {@link StoreQueryParams} with stale(standby, restoring) stores added via fetching the stores. * * @param partition The specific integer partition to be fetched from the stores list by using {@link StoreQueryParams}. * * @return String storeName */ public StoreQueryParams<T> withPartition(final Integer partition) { this.partition = partition; return this; } /** * Get the {@link StoreQueryParams} with stale(standby, restoring) stores added via fetching the stores. * * @return String storeName */ public StoreQueryParams<T> enableStaleStores() { this.staleStores = true; return this; } /** * Get the partition to be used to fetch list of Queryable store from QueryableStoreProvider. * If the function returns null, it would mean that no specific partition has been requested so all the local partitions * for the store will be returned. * * @return Integer partition */ public Integer partition() { return partition; } /** * Get the flag staleStores. If true, include standbys and recovering stores along with running stores. * * @return boolean staleStores */ public boolean staleStoresEnabled() { return staleStores; } /** * Get the store name for which key is queried by the user. * * @return String storeName */ public String storeName() { return storeName; } /** * Get the queryable store type for which key is queried by the user. * * @return QueryableStoreType queryableStoreType */ public QueryableStoreType<T> queryableStoreType() { return queryableStoreType; } } |
- Changing the
KafkaStreams#store(final String storeName, final QueryableStoreType<T> queryableStoreType, final boolean staleStores)
in in favour of the funtion function mentioned below as this one hasn't been released yet.
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public class KafkaStreams { @Deprecated public <T> T store(final String storeName, final QueryableStoreType<T> queryableStoreType) { } /** * Get a facade wrapping the local {@link StateStore} instances with the provided {@link StoreQueryParams}. * StoreQueryParams need required parameters to be set, which are {@code storeName} and if * type is accepted by the provided {@link QueryableStoreType#accepts(StateStore) queryableStoreType}. * The optional parameters to the StoreQueryParams include {@code partition} and {@code staleStores}. * The returned object can be used to query the {@link StateStore} instances. * * @param storeQueryParams If StoreQueryParams.fromNameAndType(storeName, queryableStoreType).withPartition(int partition) is used, it allow queries on the specific partition irrespective if it is a standby * or a restoring replicas in addition to active ones. * If StoreQueryParams.fromNameAndType(storeName, queryableStoreType).enableStaleStores() is used, it allow queries on standbys and restoring replicas in addition to active ones for all the local partitions on the instance. * If StoreQueryParams.fromNameAndType(storeName, queryableStoreType).enableStaleStores().withPartition(int partition), it allow queries on the specific partition irrespective if it is a standby * or a restoring replicas in addition to active ones.. * By default, if just storeQueryParams is used, it returns all the local partitions for the store which are in running state. * @param <T> return type * @return A facade wrapping the local {@link StateStore} instances * @throws InvalidStateStoreException if Kafka Streams is (re-)initializing or a store with {@code storeName} and * {@code queryableStoreType} doesn't exist */ ; // remove (was added via KIP-535 and was never release) public <T> T store(final String storeName, final QueryableStoreType<T> queryableStoreType, final boolean staleStores); // newly added public <T> T store(final StoreQueryParams<T> storeQueryParams) { ; } |
Proposed Changes:
- Add a new public class StoreQueryParams.java to class
StoreQueryParams
to set options for what kind of stores a user wants. - Create a taskId from the combination of store name and partition provided by the user.
- In
StreamThreadStateStoreProvider.java
return return only the stores for the task requested by the user and also check the condition to return only running stores or standby/recovering stores as well.
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