You are applying windowing to 'billingDataPairs' in the example above. Side input pairs with all the main input windows that exactly match or completely fall within the side input window. Common use case is a side input defined in default global window and it matches all the main input windows.
On Tue, May 15, 2018 at 4:40 PM Harshvardhan Agrawal < [email protected]> wrote: > Got it. > > Since I am not applying any windowing strategy to the side input, does > beam automatically pickup the windowing strategy for the side inputs from > the main input? By that I mean the scope of the side input would be a per > window one and it would be different for every window. Is that correct? > > Regards, > Harsh > > On Tue, May 15, 2018 at 17:54 Lukasz Cwik <[email protected]> wrote: > >> Using deduplicate + side inputs will allow you to have a consistent view >> of the account information for the entire window which can be nice since it >> gives consistent processing semantics but using a simple in memory cache to >> reduce the amount of lookups will likely be much easier to debug and >> simpler to implement and maintain. >> >> On Tue, May 15, 2018 at 2:31 PM Harshvardhan Agrawal < >> [email protected]> wrote: >> >>> Thanks Raghu! >>> >>> Lukasz, >>> >>> Do you think lookups would be a better option than side inputs in my >>> case? >>> >>> >>> On Tue, May 15, 2018 at 16:33 Raghu Angadi <[email protected]> wrote: >>> >>>> It should work. I think you need apply Distinct before looking up >>>> account info : >>>> billingDataPairs.apply(Keys.create()).apply(Distinct.create()).apply("LookupAccounts", >>>> ...). >>>> Note that all of the accounts are stored in single in-memory map. It >>>> should be small enough for that. >>>> >>>> On Tue, May 15, 2018 at 1:15 PM Harshvardhan Agrawal < >>>> [email protected]> wrote: >>>> >>>>> Well ideally, I actually made the example a little easy. In the actual >>>>> example I have multiple reference datasets. Say, I have a tuple of Account >>>>> and Product as the key. The reason we don’t do the lookup in the DoFn >>>>> directly is that we don’t want to lookup the data for the same account or >>>>> same product multiple times across workers in a window. >>>>> >>>>> What I was thinking was that it might be better to perform the lookup >>>>> only once for each account and product in a window and then supply them as >>>>> side inputs to the main input. >>>>> >>>>> On Tue, May 15, 2018 at 16:03 Lukasz Cwik <[email protected]> wrote: >>>>> >>>>>> Is there a reason you don't want to read the accounting information >>>>>> within the DoFn directly from the datastore, it seems like that would be >>>>>> your simplest approach. >>>>>> >>>>>> On Tue, May 15, 2018 at 12:43 PM Harshvardhan Agrawal < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> No we don’t receive any such information from Kafka. >>>>>>> >>>>>>> The account information in the external store does change. Every >>>>>>> time we have a change in the account information we will have to >>>>>>> recompute >>>>>>> all the billing info. Our source systems will make sure that they >>>>>>> publish >>>>>>> messages for those accounts again. >>>>>>> >>>>>>> >>>>>>> On Tue, May 15, 2018 at 15:11 Lukasz Cwik <[email protected]> wrote: >>>>>>> >>>>>>>> For each BillingModel you receive over Kafka, how "fresh" should >>>>>>>> the account information be? >>>>>>>> Does the account information in the external store change? >>>>>>>> >>>>>>>> On Tue, May 15, 2018 at 11:22 AM Harshvardhan Agrawal < >>>>>>>> [email protected]> wrote: >>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> We have certain billing data that arrives to us from Kafka. The >>>>>>>>> billing data is in json and it contains an account ID. In order for >>>>>>>>> us to >>>>>>>>> generate the final report we need to use some account data associated >>>>>>>>> with >>>>>>>>> the account id and is stored in an external database. >>>>>>>>> >>>>>>>>> It is possible that we get multiple billing info messages for the >>>>>>>>> same account. We want to be able to lookup the account information >>>>>>>>> for the >>>>>>>>> messages in a window and then supply that as a side input to the next >>>>>>>>> PTransform. >>>>>>>>> >>>>>>>>> Is it possible to achieve that in Beam? >>>>>>>>> >>>>>>>>> Here is my attempt: >>>>>>>>> >>>>>>>>> PCollection<KV<Integer, BillingModel>> billingDataPairs = >>>>>>>>> p.apply("ReadBillingInfo", KafkaIO.<String, String>read() >>>>>>>>> .withBootstrapServers(KAFKA_BOOTSTRAP_SERVER) >>>>>>>>> .withTopic(KAFKA_TOPIC) >>>>>>>>> .withKeyDeserializer(StringDeserializer.class) >>>>>>>>> .withValueDeserializer(StringDeserializer.class) >>>>>>>>> ) >>>>>>>>> .apply("Window", >>>>>>>>> Window.into(FixedWindows.of(Duration.standardSeconds(30)))) >>>>>>>>> .apply("ProcessKafkaMessages",new KafkaProcessor()); >>>>>>>>> >>>>>>>>> PCollection<KV<Integer, Iterable<BillingModel>> billingData = >>>>>>>>> billingDataPairs.apply(GroupByKey.<Integer, BillingModel>create()); >>>>>>>>> >>>>>>>>> PCollectionView<Map<Integer, Account>> accountData = >>>>>>>>> billingDataPairs.apply("LookupAccounts",new >>>>>>>>> AccountLookupClient()).apply(View.asMap()); >>>>>>>>> >>>>>>>>> billingDataPairs.apply(ParDo.of(new DoFn<KV<Integer, >>>>>>>>> BillingModel>>(){ >>>>>>>>> @ProcessElement >>>>>>>>> public void processElement(ProcessContext ctx) { >>>>>>>>> Integer accountId = ctx.element().getKey(); >>>>>>>>> Iterable<BillingModel> billingModel = >>>>>>>>> ctx.element().getValue(); >>>>>>>>> Account account = ctx.sideinput(accountData).get(accountId); >>>>>>>>> } >>>>>>>>> })); >>>>>>>>> >>>>>>>>> Regards, >>>>>>>>> Harsh >>>>>>>>> -- >>>>>>>>> >>>>>>>>> *Regards,Harshvardhan Agrawal* >>>>>>>>> *267.991.6618 | LinkedIn >>>>>>>>> <https://www.linkedin.com/in/harshvardhanagr/>* >>>>>>>>> >>>>>>>> -- >>>>>>> >>>>>>> *Regards,Harshvardhan Agrawal* >>>>>>> *267.991.6618 | LinkedIn >>>>>>> <https://www.linkedin.com/in/harshvardhanagr/>* >>>>>>> >>>>>> -- >>>>> >>>>> *Regards,Harshvardhan Agrawal* >>>>> *267.991.6618 | LinkedIn >>>>> <https://www.linkedin.com/in/harshvardhanagr/>* >>>>> >>>> -- >>> >>> *Regards,Harshvardhan Agrawal* >>> *267.991.6618 | LinkedIn <https://www.linkedin.com/in/harshvardhanagr/>* >>> >> -- > > *Regards,Harshvardhan Agrawal* > *267.991.6618 | LinkedIn <https://www.linkedin.com/in/harshvardhanagr/>* >
