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The following commit(s) were added to refs/heads/trunk by this push:
new 495c78d KAFKA-6999: Add description on read-write lock vulnerability
of ReadOnlyKeyValueStore (#5351)
495c78d is described below
commit 495c78db6f0d0d3fe111ea49f8041b5b3e32a8a4
Author: Lee Dongjin <[email protected]>
AuthorDate: Sat Jul 28 23:56:31 2018 +0900
KAFKA-6999: Add description on read-write lock vulnerability of
ReadOnlyKeyValueStore (#5351)
Reviewers: Guozhang Wang <[email protected]>
---
.../java/org/apache/kafka/streams/state/ReadOnlyKeyValueStore.java | 6 ++++++
1 file changed, 6 insertions(+)
diff --git
a/streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyKeyValueStore.java
b/streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyKeyValueStore.java
index 0632980..8725ebc 100644
---
a/streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyKeyValueStore.java
+++
b/streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyKeyValueStore.java
@@ -23,6 +23,12 @@ import
org.apache.kafka.streams.errors.InvalidStateStoreException;
* Implementations should be thread-safe as concurrent reads and writes
* are expected.
*
+ * Please note that this contract defines the thread-safe read functionality
only; it does not
+ * guarantee anything about whether the actual instance is writable by another
thread, or
+ * whether it uses some locking mechanism under the hood. For this reason,
making dependencies
+ * between the read and write operations on different StateStore instances can
cause concurrency
+ * problems like deadlock.
+ *
* @param <K> the key type
* @param <V> the value type
*/
