OK. :) If you use a separate thread, just make sure to wrap all accesses to the OutputCollector object with synchronized. From what I see it doesn't look like you use OutputCollector, but maybe, for example, it's best to ack the messages in your response handler. If many response handlers can be running simultaneously, then you would need to synchronize the calls to ack() as they are made on the OutputCollector.
On Tue, Dec 16, 2014 at 11:16 AM, Idan Fridman <[email protected]> wrote: > Oh I know what is all synchronized about. Just I wasn't sure if the > synchronization > in my storm bolt is concerned only to the execute method. > > > > 2014-12-16 18:08 GMT+02:00 Nathan Leung <[email protected]>: >> >> you should look up the synchronized keyword in java: >> >> http://docs.oracle.com/javase/tutorial/essential/concurrency/syncmeth.html >> http://docs.oracle.com/javase/tutorial/essential/concurrency/locksync.html >> > > On Tue, Dec 16, 2014 at 9:50 AM, Idan Fridman <[email protected]> wrote: > >> Thanks for your response Itay. I understood you. >> How would you modify the above code to make sure I am synchronizing/make >> calls from the same Thread ? >> >> 2014-12-16 16:43 GMT+02:00 Itai Frenkel <[email protected]>: >>> >>> Idan, >>> >>> >>> Consider you have 1000 concurrent tuples ... and the spout does not >>> throttle traffic. It means that the last bolt would be >>> handling 1000 concurrent requests. Now consider you have 100,000 concurrent >>> tuples.... Eventually the operating system or the NIO buffer would exhaust >>> its resources. You would have been better off with throtteling. >>> >>> >>> The output collector is the object that you perform "ack" or "fail" >>> the tuple. You probably call them from a future callback. Make sure that >>> all of these callbacks are called from the same thread, or are synchronized. >>> >>> >>> Itai >>> >>> >>> ------------------------------ >>> *From:* Idan Fridman <[email protected]> >>> *Sent:* Tuesday, December 16, 2014 3:58 PM >>> *To:* [email protected] >>> *Subject:* Re: Using AsyncHttpReuqest inside a Bolt >>> >>> >>> Hi, >>> >>> Any non-blocking bolt does not push back on the previous bolt if it is >>> out of resources. So you should consider using max-spout-pending for spout >>> level throttling. >>> >>> >>> @Itai, >>> My async bolt is the last bolt in the chain. so i guess I dont have this >>> problem?? >>> >>> Keep in mind you'll need to synchronize the OutputCollector when your >>> NIO response workers handle the returned requests as OutputCollector is not >>> thread safe. >>> >>> @Michael, >>> I am not sure how the OutputCollector is concerned to my issue? >>> >>> This is my execution code.. that code could caouse me any side-effects >>> in my topology? >>> >>> >>> @Override >>> public void execute(Tuple tuple, BasicOutputCollector basicOutputCollector) >>> { >>> >>> PushMessage pushMessage = (PushMessage) >>> tuple.getValueByField("pushMessage"); >>> final String messageId = pushMessage.getMessageId(); >>> asyncHttpClient.preparePost("some_url").execute(new >>> AsyncCompletionHandler<Response>() { >>> @Override >>> public Response onCompleted(Response response) throws Exception { >>> String innerMessageId = messageId; >>> System.out.printf("\n messageId=" + innerMessageId + >>> "responseBody=" + response.getResponseBody()); >>> return response; >>> } >>> >>> @Override >>> public void onThrowable(Throwable t) { >>> t.printStackTrace(); >>> } >>> }); >>> } >>> >>> thanks. >>> >>> >>> 2014-12-15 19:30 GMT+02:00 Michael Rose <[email protected]>: >>>> >>>> Keep in mind you'll need to synchronize the OutputCollector when your >>>> NIO response workers handle the returned requests as OutputCollector is not >>>> thread safe. >>> >>> >>> Michael Rose (@Xorlev <https://twitter.com/xorlev>) >>> Senior Platform Engineer, FullContact <http://www.fullcontact.com/> >>> [email protected] >>> >>> On Mon, Dec 15, 2014 at 9:20 AM, Itai Frenkel <[email protected]> wrote: >>>> >>>> Hi, >>>> >>>> >>>> Any non-blocking bolt does not push back on the previous bolt if it >>>> is out of resources. So you should consider using max-spout-pending for >>>> spout level throttling. >>>> >>>> >>>> Regards, >>>> >>>> Itai >>>> ------------------------------ >>>> *From:* Idan Fridman <[email protected]> >>>> *Sent:* Monday, December 15, 2014 10:19 AM >>>> *To:* [email protected] >>>> *Subject:* Using AsyncHttpReuqest inside a Bolt >>>> >>>> Hi All, >>>> My bolt need to dispatch async request to remote service. >>>> >>>> I am using AsyncHttpReuest library( >>>> https://github.com/AsyncHttpClient/async-http-client) which based on >>>> NIO channels to get the response asynchronously while not allocating Thread >>>> for each request. >>>> >>>> I was wondering if any side-effects could cause this implementation >>>> within Storm Bolt ? >>>> >>>> thank you. >>>> >>> >
