Steps:
1. Implement IBackingMap interface for DynamoDB
2. Use OpaqueTridentKafkaSpout to read Kafka stream
3. Use OpaqueMap with your IBackingMap implementation within the topology
4. All your logic will now have exactly once semantics inside your Trident
topology
This is all on that wiki page. L
I am new to Storm and not able to understand clearly how to use Trident
state to achieve exactly once semantics with external database. Can you
please elaborate?
May be a use case with one external database as below:
One of the sample use case could be as below:
1) Read an event from Kafka
2) Par
That information is not accurate. Trident can have exactly once semantics
with *any* external database. See this page for the details:
https://storm.apache.org/documentation/Trident-state.html
On Tue, Jan 12, 2016 at 3:55 AM, Matthias J. Sax wrote:
> Hi,
>
> Storm does only guarantee exactly on
Hi,
Storm does only guarantee exactly once *within* the system. If you write
to an external consumer you need to ensure that writes are idempotent or
de-duplicate externally.
About Tridents internals, start to read the documentation here:
https://storm.apache.org/documentation/Transactional-topo
Hi,
We are evaluating storm with Trident to process events from Kafka in an
exactly once manner so that the consumer application need not worry about
the de-duplication logic.
One of the sample use case could be as below:
1) Read an event from Kafka
2) Parse the JSON
3) Process the data
4) Writ
