Repository: flink Updated Branches: refs/heads/master 35b4da273 -> 6744b852d
[hotfix][docs] Add warning to Cassandra documentation Project: http://git-wip-us.apache.org/repos/asf/flink/repo Commit: http://git-wip-us.apache.org/repos/asf/flink/commit/6744b852 Tree: http://git-wip-us.apache.org/repos/asf/flink/tree/6744b852 Diff: http://git-wip-us.apache.org/repos/asf/flink/diff/6744b852 Branch: refs/heads/master Commit: 6744b852dfc95ac1da9152613460a622f1633cf5 Parents: 35b4da2 Author: Robert Metzger <rmetz...@apache.org> Authored: Thu Jun 23 13:48:48 2016 +0200 Committer: zentol <ches...@apache.org> Committed: Mon Jun 27 12:17:03 2016 +0200 ---------------------------------------------------------------------- docs/apis/streaming/connectors/cassandra.md | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/flink/blob/6744b852/docs/apis/streaming/connectors/cassandra.md ---------------------------------------------------------------------- diff --git a/docs/apis/streaming/connectors/cassandra.md b/docs/apis/streaming/connectors/cassandra.md index 18732fb..28ad244 100644 --- a/docs/apis/streaming/connectors/cassandra.md +++ b/docs/apis/streaming/connectors/cassandra.md @@ -56,10 +56,10 @@ The following configuration methods can be used: 4. enableWriteAheadLog([CheckpointCommitter committer]) 5. build() -setQuery() sets the query that is executed for every value the sink receives. -setHost() sets the cassandra host/port to connect to. This method is intended for simple use-cases. -setClusterBuilder() sets the cluster builder that is used to configure the connection to cassandra. The setHost() functionality can be subsumed with this method. -enableWriteAheadLog() is an optional method, that allows exactly-once processing for non-deterministic algorithms. +*setQuery()* sets the query that is executed for every value the sink receives. +*setHost()* sets the cassandra host/port to connect to. This method is intended for simple use-cases. +*setClusterBuilder()* sets the cluster builder that is used to configure the connection to cassandra. The *setHost()* functionality can be subsumed with this method. +*enableWriteAheadLog()* is an optional method, that allows exactly-once processing for non-deterministic algorithms. A checkpoint committer stores additional information about completed checkpoints in some resource. This information is used to prevent a full replay of the last @@ -67,7 +67,7 @@ completed checkpoint in case of a failure. You can use a `CassandraCommitter` to store these in a separate table in cassandra. Note that this table will NOT be cleaned up by Flink. -build() finalizes the configuration and returns the CassandraSink. +*build()* finalizes the configuration and returns the CassandraSink. Flink can provide exactly-once guarantees if the query is idempotent (meaning it can be applied multiple times without changing the result) and checkpointing is enabled. In case of a failure the failed @@ -79,7 +79,10 @@ database in an inconsitent state since part of the first attempt may already be The write-ahead log guarantees that the replayed checkpoint is identical to the first attempt. Note that that enabling this feature will have an adverse impact on latency. -Example: +<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> + + +#### Example <div class="codetabs" markdown="1"> <div data-lang="java" markdown="1"> @@ -107,6 +110,8 @@ CassandraSink.addSink(input) }) .build(); {% endhighlight %} +</div> +</div> The Cassandra sinks support both tuples and POJO's that use DataStax annotations. Flink automatically detects which type of input is used.