Package org.apache.kafka.streams.state
Interface SessionStore<K,AGG>
- Type Parameters:
K
- type of the record keysAGG
- type of the aggregated values
- All Superinterfaces:
ReadOnlySessionStore<K,
,AGG> StateStore
Interface for storing the aggregated values of sessions.
The key is internally represented as Windowed<K>
that comprises the plain
key and the Window
that represents window start- and end-timestamp.
If two sessions are merged, a new session with new start- and end-timestamp must be inserted into the store while the two old sessions must be deleted.
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Method Summary
Modifier and TypeMethodDescriptiondefault KeyValueIterator<Windowed<K>,
AGG> backwardFindSessions
(K key, Instant earliestSessionEndTime, Instant latestSessionStartTime) Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest.default KeyValueIterator<Windowed<K>,
AGG> backwardFindSessions
(K keyFrom, K keyTo, Instant earliestSessionEndTime, Instant latestSessionStartTime) Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest.default AGG
fetchSession
(K key, Instant sessionStartTime, Instant sessionEndTime) Get the value of key from a single session.default KeyValueIterator<Windowed<K>,
AGG> findSessions
(long earliestSessionEndTime, long latestSessionEndTime) Return all the session window entries that ends between the specified range (both ends are inclusive).default KeyValueIterator<Windowed<K>,
AGG> findSessions
(K key, Instant earliestSessionEndTime, Instant latestSessionStartTime) Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest.default KeyValueIterator<Windowed<K>,
AGG> findSessions
(K keyFrom, K keyTo, Instant earliestSessionEndTime, Instant latestSessionStartTime) Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest.void
Write the aggregated value for the provided key to the storevoid
Remove the session aggregated with providedWindowed
key from the storeMethods inherited from interface org.apache.kafka.streams.state.ReadOnlySessionStore
backwardFetch, backwardFetch, backwardFindSessions, backwardFindSessions, fetch, fetch, fetchSession, findSessions, findSessions
Methods inherited from interface org.apache.kafka.streams.processor.StateStore
close, flush, getPosition, init, init, isOpen, name, persistent, query
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Method Details
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findSessions
default KeyValueIterator<Windowed<K>,AGG> findSessions(long earliestSessionEndTime, long latestSessionEndTime) Return all the session window entries that ends between the specified range (both ends are inclusive). This function would be used to retrieve all closed and immutable windows.- Parameters:
earliestSessionEndTime
- earliest session end time to search from, inclusivelatestSessionEndTime
- latest session end time to search to, inclusive
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findSessions
default KeyValueIterator<Windowed<K>,AGG> findSessions(K key, Instant earliestSessionEndTime, Instant latestSessionStartTime) Description copied from interface:ReadOnlySessionStore
Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest. I.e., earliestSessionEndTime is the lower bound of the search interval and latestSessionStartTime is the upper bound of the search interval, and the method returns all sessions that overlap with the search interval. Thus, if a session ends before earliestSessionEndTime, or starts after latestSessionStartTime if won't be contained in the result:earliestSessionEndTime: ESET latestSessionStartTime: LSST [ESET............LSST] [not-included] [included] [included] [included] [not-included]
This iterator must be closed after use.
- Specified by:
findSessions
in interfaceReadOnlySessionStore<K,
AGG> - Parameters:
key
- the key to return sessions forearliestSessionEndTime
- the end timestamp of the earliest session to search for, where iteration starts.latestSessionStartTime
- the end timestamp of the latest session to search for, where iteration ends.- Returns:
- iterator of sessions with the matching key and aggregated values, from earliest to latest session time.
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backwardFindSessions
default KeyValueIterator<Windowed<K>,AGG> backwardFindSessions(K key, Instant earliestSessionEndTime, Instant latestSessionStartTime) Description copied from interface:ReadOnlySessionStore
Fetch any sessions with the matching key and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest. I.e., earliestSessionEndTime is the lower bound of the search interval and latestSessionStartTime is the upper bound of the search interval, and the method returns all sessions that overlap with the search interval. Thus, if a session ends before earliestSessionEndTime, or starts after latestSessionStartTime if won't be contained in the result:earliestSessionEndTime: ESET latestSessionStartTime: LSST [ESET............LSST] [not-included] [included] [included] [included] [not-included]
This iterator must be closed after use.
- Specified by:
backwardFindSessions
in interfaceReadOnlySessionStore<K,
AGG> - Parameters:
key
- the key to return sessions forearliestSessionEndTime
- the end timestamp of the earliest session to search for, where iteration ends.latestSessionStartTime
- the end timestamp of the latest session to search for, where iteration starts.- Returns:
- backward iterator of sessions with the matching key and aggregated values, from latest to earliest session time.
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findSessions
default KeyValueIterator<Windowed<K>,AGG> findSessions(K keyFrom, K keyTo, Instant earliestSessionEndTime, Instant latestSessionStartTime) Description copied from interface:ReadOnlySessionStore
Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from earliest to latest. I.e., earliestSessionEndTime is the lower bound of the search interval and latestSessionStartTime is the upper bound of the search interval, and the method returns all sessions that overlap with the search interval. Thus, if a session ends before earliestSessionEndTime, or starts after latestSessionStartTime if won't be contained in the result:earliestSessionEndTime: ESET latestSessionStartTime: LSST [ESET............LSST] [not-included] [included] [included] [included] [not-included]
This iterator must be closed after use.
- Specified by:
findSessions
in interfaceReadOnlySessionStore<K,
AGG> - Parameters:
keyFrom
- The first key that could be in the range A null value indicates a starting position from the first element in the store.keyTo
- The last key that could be in the range A null value indicates that the range ends with the last element in the store.earliestSessionEndTime
- the end timestamp of the earliest session to search for, where iteration starts.latestSessionStartTime
- the end timestamp of the latest session to search for, where iteration ends.- Returns:
- iterator of sessions with the matching keys and aggregated values, from earliest to latest session time.
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backwardFindSessions
default KeyValueIterator<Windowed<K>,AGG> backwardFindSessions(K keyFrom, K keyTo, Instant earliestSessionEndTime, Instant latestSessionStartTime) Description copied from interface:ReadOnlySessionStore
Fetch any sessions in the given range of keys and the sessions end is ≥ earliestSessionEndTime and the sessions start is ≤ latestSessionStartTime iterating from latest to earliest. I.e., earliestSessionEndTime is the lower bound of the search interval and latestSessionStartTime is the upper bound of the search interval, and the method returns all sessions that overlap with the search interval. Thus, if a session ends before earliestSessionEndTime, or starts after latestSessionStartTime if won't be contained in the result:earliestSessionEndTime: ESET latestSessionStartTime: LSST [ESET............LSST] [not-included] [included] [included] [included] [not-included]
This iterator must be closed after use.
- Specified by:
backwardFindSessions
in interfaceReadOnlySessionStore<K,
AGG> - Parameters:
keyFrom
- The first key that could be in the range A null value indicates a starting position from the first element in the store.keyTo
- The last key that could be in the range A null value indicates that the range ends with the last element in the store.earliestSessionEndTime
- the end timestamp of the earliest session to search for, where iteration ends.latestSessionStartTime
- the end timestamp of the latest session to search for, where iteration starts.- Returns:
- backward iterator of sessions with the matching keys and aggregated values, from latest to earliest session time.
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fetchSession
Description copied from interface:ReadOnlySessionStore
Get the value of key from a single session.- Specified by:
fetchSession
in interfaceReadOnlySessionStore<K,
AGG> - Parameters:
key
- the key to fetchsessionStartTime
- start timestamp of the sessionsessionEndTime
- end timestamp of the session- Returns:
- The value or
null
if no session with the exact start and end timestamp exists for the given key
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remove
Remove the session aggregated with providedWindowed
key from the store- Parameters:
sessionKey
- key of the session to remove- Throws:
NullPointerException
- If null is used for sessionKey.
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put
Write the aggregated value for the provided key to the store- Parameters:
sessionKey
- key of the session to writeaggregate
- the aggregated value for the session, it can be null; if the serialized bytes are also null it is interpreted as deletes- Throws:
NullPointerException
- If null is used for sessionKey.
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