Github user mcfongtw commented on a diff in the pull request:
https://github.com/apache/flink/pull/4696#discussion_r140620261
--- Diff: docs/dev/connectors/cassandra.md ---
@@ -78,76 +96,195 @@ Note that that enabling this feature will have an
adverse impact on latency.
<p style="border-radius: 5px; padding: 5px" class="bg-danger"><b>Note</b>:
The write-ahead log functionality is currently experimental. In many cases it
is sufficent to use the connector without enabling it. Please report problems
to the development mailing list.</p>
+### Checkpointing and Fault Tolerance
+With checkpointing enabled, Cassandra Sink guarantees at-least-once
delivery of action requests to C* instance.
-#### Example
+<p style="border-radius: 5px; padding: 5px"
class="bg-danger"><b>Note</b>:However, current Cassandra Sink implementation
does not flush the pending mutations before the checkpoint was triggered.
Thus, some in-flight mutations might not be replayed when the job recovered.
</p>
+
+More details on [checkpoints docs]({{ site.baseurl
}}/dev/stream/state/checkpointing.html) and [fault tolerance guarantee docs]({{
site.baseurl }}/dev/connectors/guarantees.html)
+
+To enable fault tolerant guarantee, checkpointing of the topology needs to
be enabled at the execution environment:
--- End diff --
Very true. Thanks.
---
