One question Dawid: If I maintain a ValueState of Maps if this is what you were referring to:
1. In my use case, I am registering the timeout for a key when I store that in state. i.e. If I do not receive the matching event with same key from other stream, then I would like to receive a callback and invoke a onTimer method from which I am pushing the unmatched events to sideouput. 2. In case of ValueState, if I register the callback timeout on current key, for the past information in ValueState will flink give me the callback for the events state at that point of time in past? as ValueState will get updated with most recent user key on every events arrival. ________________________________ From: Jaswin Shah <jaswin.s...@outlook.com> Sent: 25 May 2020 14:47 To: Dawid Wysakowicz <dwysakow...@apache.org>; user@flink.apache.org <user@flink.apache.org>; ankit.sing...@paytm.com <ankit.sing...@paytm.com>; isha.sing...@paytm.com <isha.sing...@paytm.com> Subject: Re: Timeout Callbacks issue -Flink If I understand correctly, you are trying to tell that I should have valueState of Map? ________________________________ From: Jaswin Shah Sent: 25 May 2020 14:43 To: Dawid Wysakowicz <dwysakow...@apache.org>; user@flink.apache.org <user@flink.apache.org>; ankit.sing...@paytm.com <ankit.sing...@paytm.com>; isha.sing...@paytm.com <isha.sing...@paytm.com> Subject: Re: Timeout Callbacks issue -Flink Thanks for responding Dawid. I would like to know more about MapState solution you talked about. As per my understanding valueState maintains a single value at any point of time. So, here what I want to maintain is the first streams information until matching event have not found in second stream. So, in that case how valueState could benefit me? Can you please explain me that, might be I have understood it incorrectly what you are trying to convey here. Thanks, Jaswin ________________________________ From: Dawid Wysakowicz Sent: Monday, May 25, 2020 14:23 To: Jaswin Shah; user@flink.apache.org; ankit.sing...@paytm.com; isha.sing...@paytm.com Subject: Re: Timeout Callbacks issue -Flink Hi Jaswin, I can't see any obvious problems in your code. It looks rather correct. What exactly do you mean that "callback is coming earlier than registered callback timeout"? Could you explain that with some examples? As for the different timezones. Flink does not make any assumptions on the timestamp. It uses it simply as longs. I'd suggest revisiting your timestamp extraction logic to make sure it performs the extraction correctly. I don't know how your data encodes the timestamps, but I think you have a bug or two there ;) The "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" gives me an impression that this field has timestamps in UTC, but you are parsing it in your JVM local time zone. You treat the 'Z' as a literal (https://stackoverflow.com/questions/19112357/java-simpledateformatyyyy-mm-ddthhmmssz-gives-timezone-as-ist). I don't know what the other field represents but you are also parsing it in a local timezone. If the field represents local date it is probably correct. To mitigate those problems I'd strongly recommend using the java.time API. For the extractCartTimeStamp you could use Instant.parse("...").toEpochMilli. It expects the format you are receiving. For the extractPGTimeStamp you could use LocalDateTime.parse("..."), by default it uses the format you are receiving. Then you should convert the local date time to an instant LocalDateTime.parse("...").atZone(/* the zone which this date represents */).toInstant().toEpochMilli(); This has nothing to do with Flink though ;) BTW one Flink issue I can see is that I think you don't need to use a MapState there. Any kind of state in a KeyedCoProcessFunction is always scoped to the current key. Therefore if you only ever put items under the currentKey you will have at most single element in your map. Think of the MapState as a map of maps MapState<UserKey, Value> = Map<CurrentKey, Map<UserKey, Value>>. In your case a ValueState should be enough imo. Best, Dawid On 23/05/2020 14:39, Jaswin Shah wrote: ++ Here, I am registering the callback time for an even with processing time and calculating the time value as events time + expiryTimeout value. Can this be the issue here due to hybrid timings usage? Also, do we need any special handling if we use event time semantics for callback timeouts registrations? Thanks, Jaswin ________________________________ From: Jaswin Shah <jaswin.s...@outlook.com><mailto:jaswin.s...@outlook.com> Sent: 23 May 2020 17:18 To: user@flink.apache.org<mailto:user@flink.apache.org> <user@flink.apache.org><mailto:user@flink.apache.org>; Arvid Heise <ar...@ververica.com><mailto:ar...@ververica.com>; Yun Tang <myas...@live.com><mailto:myas...@live.com> Subject: Timeout Callbacks issue -Flink Hi, I am running flink job with following functionality: 1. I consume stream1 and stream2 from two kafka topics and assign the watermarks to the events of two streams by extracting the timestamps from the events in streams. 2. Then, I am connecting two streams and calling KeyedCoProcessFunction on connectedStream. 3. I have processElement1 method and processElement2 methods which receive the events of two streams 1 and 2 and do the join logic as shown in below code snippet. 4. I have shared mapstate for two streams. 5. When an event comes to processElement method, I register the callback time for that message to ensure if corresponding matching message is not arrived from other stream, I will send the message to sideOutput on invocation of callback method i.e. onTimer. Something is getting wrong in the callback times registrations for events due to which for many messages of stream2 the callback is coming earlier than registered callback timeout. Also, the events from stream 2 are based on GMT times +5:30 as I can see in the timevalue in event message, for stream1 it;s normal TZ only. Though I am weak in analysing the timeout formats so could be wrong in analysis this side. Below is code snippets I have implemented for KeyedCoProcessFunctions and timestamp calculations and watermarks registrations. /** * CoProcessFuntion to process cart and pg messages connected using connect operator. * @author jaswin.shah * @version $Id: CartPGCoprocessFunction.java, v 0.1 2020-05-15 11:52 PM jaswin.shah Exp $$ */ public class CartPGCoprocessFunction extends KeyedCoProcessFunction<String,CartMessage, PaymentNotifyRequestWrapper, ResultMessage> { private static final Logger logger = LoggerFactory.getLogger(CartPGCoprocessFunction.class); /** * Map state for cart messages, orderId+mid is key and cartMessage is value. */ private static MapState<String, CartPG> cartPgState = null; /** * Intializations for cart and pg mapStates * * @param config */ @Override public void open(Configuration config) { MapStateDescriptor<String, CartPG> cartPgMapStateDescriptor = new MapStateDescriptor<> ( Constants.CART_DATA, TypeInformation.of(String.class), TypeInformation.of(CartPG.class) ); cartPgState = getRuntimeContext().getMapState(cartPgMapStateDescriptor); } /** * * @return */ @Override public void onTimer(long timestamp, OnTimerContext ctx, Collector<ResultMessage> out) throws Exception { logger.info("On timer called key is {}",ctx.getCurrentKey()); String searchKey = ctx.getCurrentKey(); CartPG cartPg = cartPgState.get(searchKey); if(Objects.nonNull(cartPg)) { ctx.output(CartPGSideOutput.getOutputTag(), cartPgState.get(ctx.getCurrentKey())); cartPgState.remove(searchKey); } } /** * 1. Get orderId+mid from cartMessage and check in PGMapState if an entry is present. * 2. If present, match, checkDescripancy, process and delete entry from pgMapState. * 3. If not present, add orderId+mid as key and cart object as value in cartMapState. * @param cartMessage * @param context * @param collector * @throws Exception */ @Override public void processElement1(CartMessage cartMessage, Context context, Collector<ResultMessage> collector) throws Exception { Long cartEventTimeStamp = context.timestamp(); logger.info("cart time : {} ",cartEventTimeStamp); context.timerService().registerProcessingTimeTimer(cartEventTimeStamp+ ConfigurationsManager.getMaxWaitTimeForPGMessage()); String searchKey = cartMessage.createJoinStringCondition(); CartPG cartPG = cartPgState.get(searchKey); if(Objects.nonNull(cartPG) && Objects.nonNull(cartPG.getPgMessage())) { generateResultMessage(cartMessage,cartPG.getPgMessage(),collector); cartPgState.remove(searchKey); } else { cartPG = new CartPG(); cartPG.setCartMessage(cartMessage); cartPgState.put(searchKey,cartPG); } } /** * 1. Get orderId+mid from pgMessage and check in cartMapState if an entry is present. * 2. If present, match, checkDescripancy, process and delete entry from cartMapState. * 3. If not present, add orderId+mid as key and cart object as value in pgMapState. * @param pgMessage * @param context * @param collector * @throws Exception */ @Override public void processElement2(PaymentNotifyRequestWrapper pgMessage, Context context, Collector<ResultMessage> collector) throws Exception { Long pgEventTimeStamp = context.timestamp(); logger.info("pg time : {} ",pgEventTimeStamp); context.timerService().registerProcessingTimeTimer(pgEventTimeStamp+ConfigurationsManager.getMaxWaitTimeForCartMessage()); String searchKey = pgMessage.createJoinStringCondition(); CartPG cartPG = cartPgState.get(searchKey); if(Objects.nonNull(cartPG) && Objects.nonNull(cartPG.getCartMessage())) { generateResultMessage(cartPG.getCartMessage(),pgMessage,collector); cartPgState.remove(searchKey); } else { cartPG = new CartPG(); cartPG.setPgMessage(pgMessage); cartPgState.put(searchKey,cartPG); } } /** * Create ResultMessage from cart and pg messages. * * @param cartMessage * @param pgMessage * @return */ private void generateResultMessage(CartMessage cartMessage, PaymentNotifyRequestWrapper pgMessage,Collector<ResultMessage> collector) { ResultMessage resultMessage = new ResultMessage(); Payment payment = null; //Logic should be in cart: check for (Payment pay : cartMessage.getPayments()) { if (StringUtils.equals(Constants.FORWARD_PAYMENT, pay.mapToPaymentTypeInPG()) && StringUtils.equals(Constants.PAYTM_NEW_PROVIDER, pay.getProvider())) { payment = pay; break; } } if(Objects.isNull(payment)) { return; } resultMessage.setOrderId(cartMessage.getId()); resultMessage.setMid(payment.getMid()); resultMessage.setCartOrderStatus(cartMessage.mapToOrderStatus().getCode()); resultMessage.setPgOrderStatus(pgMessage.getOrderStatus()); resultMessage.setCartOrderCompletionTime(payment.getUpdated_at()); resultMessage.setPgOrderCompletionTime(pgMessage.getCreatedTime()); resultMessage.setPgOrderAmount(pgMessage.getOrderAmount().getValue()); resultMessage.setCartOrderAmount(String.valueOf(Math.round(cartMessage.getGrandtotal()))); resultMessage.setCartPaymethod(payment.getPayment_method()); resultMessage.setPgPaymethod(pgMessage.getPaymentView().getPayOptionInfos()[0].getPayMethod()); checkDescripancyAndCollectResult(resultMessage,collector); } /** * Evaluate if there is descripancy of any fields between the messages from two different systems. * Write all the descripancy logic here. * * @param resultMessage */ private void checkDescripancyAndCollectResult(ResultMessage resultMessage, Collector<ResultMessage> collector) { if (!StringUtils.equalsIgnoreCase(resultMessage.getCartOrderStatus(), resultMessage.getPgOrderStatus())) { resultMessage.setDescripancyType(DescripancyTypeEnum.ORDER_STATUS_DESCRIPANCY); collector.collect(resultMessage.clone()); } if (!resultMessage.getCartOrderAmount().equals(resultMessage.getPgOrderAmount())) { resultMessage.setDescripancyType(DescripancyTypeEnum.PAY_AMOUNT_DESCRIPANCY); collector.collect(resultMessage.clone()); } if (!StringUtils.equalsIgnoreCase(resultMessage.getCartPaymethod(), resultMessage.getPgPaymethod())) { resultMessage.setDescripancyType(DescripancyTypeEnum.PAY_METHOD_DESCRIPANCY); collector.collect(resultMessage.clone()); } } } /** * Connect to cart and pg streams and process * * @param cartStream * @param pgStream * @return */ private SingleOutputStreamOperator<ResultMessage> connectCartPGStreamsAndProcess(SingleOutputStreamOperator<CartMessage> cartStream, SingleOutputStreamOperator<PaymentNotifyRequestWrapper> pgStream) { return cartStream.connect(pgStream).keyBy(new CartJoinColumnsSelector(),new PGJoinColumnsSelector()) .process(new CartPGCoprocessFunction()); } private final static SimpleDateFormat cartInputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); private final static SimpleDateFormat pgInputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss"); public static Long extractCartTimeStamp(CartMessage cartMessage){ try { Date orderTimeStamp = cartInputFormat.parse(cartMessage.fetchOrderCompletionTime()); return orderTimeStamp.getTime(); } catch (ParseException e) { logger.error("Exception in converting cart message timeStamp..",e); } return Instant.now().toEpochMilli(); } public static Long extractPGTimeStamp(PaymentNotifyRequestWrapper pgMessage){ try { Date orderTimeStamp = pgInputFormat.parse(pgMessage.getPaymentView().getPaidTime()); return orderTimeStamp.getTime(); } catch (ParseException e) { logger.error("Exception in converting pg message timeStamp..",e); } return Instant.now().toEpochMilli(); } private SingleOutputStreamOperator<CartMessage> processCartStream(ParameterTool parameter, StreamExecutionEnvironment executionEnvironment) { //1. Consume cartStream SingleOutputStreamOperator<CartMessage> cartStream = executionEnvironment.addSource(createCartConsumer()); cartStream.name(Constants.CART_SYSTEM); //2. Filter cart messages SingleOutputStreamOperator<CartMessage> filteredCartStream = cartStream.filter(new CartFilterFunction()) ; //3. Map carts data filteredCartStream = CartMappingService.mapCartsData(filteredCartStream); //4. Assign timestamps and watermarks filteredCartStream.assignTimestampsAndWatermarks(new BoundedOutOfOrdernessTimestampExtractor<CartMessage>(Time.milliseconds(Long.parseLong(parameter.get(Constants.CART_MAX_OUT_OF_ORDERNESS)))) { @Override public long extractTimestamp(CartMessage cartMessage) { return DateTimeUtils.extractCartTimeStamp(cartMessage); } }); return filteredCartStream; } private SingleOutputStreamOperator<PaymentNotifyRequestWrapper> processPgStream(ParameterTool parameter, StreamExecutionEnvironment executionEnvironment) { //1. Consume pg streams SingleOutputStreamOperator<PaymentNotifyRequestWrapper> pgStream = executionEnvironment.addSource(createPGConsumer()); pgStream.name(Constants.PG_SYSTEM); //2. Assign timestamps and watermarks to pg messages pgStream.assignTimestampsAndWatermarks(new BoundedOutOfOrdernessTimestampExtractor<PaymentNotifyRequestWrapper>(Time.milliseconds(Long.parseLong(parameter.get(Constants.PG_MAX_OUT_OF_ORDERNESS)))) { @Override public long extractTimestamp(PaymentNotifyRequestWrapper pgMessage) { return DateTimeUtils.extractPGTimeStamp(pgMessage); } }); return pgStream; } Can anyone please help what can be the issue here and if there is somewrong time values handled in the code here. Help will be highly appreciated.
