Kafka streams using context forward from processor called in dsl api
I have a processor and would like to call context.forward() in it. However I feel like I need to set a sink topic for it to actually get forwarded. If I was using the Toplogy I would just .addSource(), .addProcessor(), .addSink(). However with the DSL I have a StreamsBuilder/KStream. Is there anyway to use context.forward() when calling a processor from the dsl?
NOTE: I need to use a processor instead of a transform as I have custom logic on when to forward records down stream.
stream.process(() -> new WindowAggregatorProcessor(storeName), storeName);
apache-kafka-streams
add a comment |
I have a processor and would like to call context.forward() in it. However I feel like I need to set a sink topic for it to actually get forwarded. If I was using the Toplogy I would just .addSource(), .addProcessor(), .addSink(). However with the DSL I have a StreamsBuilder/KStream. Is there anyway to use context.forward() when calling a processor from the dsl?
NOTE: I need to use a processor instead of a transform as I have custom logic on when to forward records down stream.
stream.process(() -> new WindowAggregatorProcessor(storeName), storeName);
apache-kafka-streams
add a comment |
I have a processor and would like to call context.forward() in it. However I feel like I need to set a sink topic for it to actually get forwarded. If I was using the Toplogy I would just .addSource(), .addProcessor(), .addSink(). However with the DSL I have a StreamsBuilder/KStream. Is there anyway to use context.forward() when calling a processor from the dsl?
NOTE: I need to use a processor instead of a transform as I have custom logic on when to forward records down stream.
stream.process(() -> new WindowAggregatorProcessor(storeName), storeName);
apache-kafka-streams
I have a processor and would like to call context.forward() in it. However I feel like I need to set a sink topic for it to actually get forwarded. If I was using the Toplogy I would just .addSource(), .addProcessor(), .addSink(). However with the DSL I have a StreamsBuilder/KStream. Is there anyway to use context.forward() when calling a processor from the dsl?
NOTE: I need to use a processor instead of a transform as I have custom logic on when to forward records down stream.
stream.process(() -> new WindowAggregatorProcessor(storeName), storeName);
apache-kafka-streams
apache-kafka-streams
asked Nov 13 '18 at 22:25
ChrisChris
3253417
3253417
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
stream.process()
is a terminal operation in the DSL. You can use stream.transform()
instead to get an output stream. A Transformer
is basically the same as a Processor
.
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).
– Matthias J. Sax
Nov 14 '18 at 3:59
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53290440%2fkafka-streams-using-context-forward-from-processor-called-in-dsl-api%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
stream.process()
is a terminal operation in the DSL. You can use stream.transform()
instead to get an output stream. A Transformer
is basically the same as a Processor
.
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).
– Matthias J. Sax
Nov 14 '18 at 3:59
add a comment |
stream.process()
is a terminal operation in the DSL. You can use stream.transform()
instead to get an output stream. A Transformer
is basically the same as a Processor
.
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).
– Matthias J. Sax
Nov 14 '18 at 3:59
add a comment |
stream.process()
is a terminal operation in the DSL. You can use stream.transform()
instead to get an output stream. A Transformer
is basically the same as a Processor
.
stream.process()
is a terminal operation in the DSL. You can use stream.transform()
instead to get an output stream. A Transformer
is basically the same as a Processor
.
answered Nov 13 '18 at 23:32
Matthias J. SaxMatthias J. Sax
29.6k35278
29.6k35278
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).
– Matthias J. Sax
Nov 14 '18 at 3:59
add a comment |
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).
– Matthias J. Sax
Nov 14 '18 at 3:59
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
With a transformer dont you need to return the value you want to go down stream. In my case I have a context.schedule() that may or may not want to forward content. For your suggestion to work I would need to always have transform() return null and the have context.forward() pass the value to the next operation. Which I dont think will work?
– Chris
Nov 14 '18 at 0:37
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.
context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).– Matthias J. Sax
Nov 14 '18 at 3:59
What you say will work. Btw: we are currently adding a "FlatTransformer" to allow you to emit more than one value via return.
context.forward
will still be available (it's disadvantage is, that's not type safe; but it works).– Matthias J. Sax
Nov 14 '18 at 3:59
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53290440%2fkafka-streams-using-context-forward-from-processor-called-in-dsl-api%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown