Tushar, Great! My final question, I have been searching, and haven't found any good examples of setting up a complex data type, and storing and retrieving it from HDHT within an operator. My data that would want to store would look like:
Field Name Field Type OrderNumber integer (this is the key) Status integer 855Data string 856Data string 910Data string Any examples that you can point me to show me the best way to set up accessing the HDHT? Thanks, Jim -----Original Message----- From: Tushar Gosavi [mailto:[email protected]] Sent: Thursday, September 1, 2016 1:06 PM To: [email protected] Subject: Re: HDHT question - looking for the datatorrent gurus! Hi Jim, Yes this is what I had in mind, The manage state needs to have separate input for each of the 5 operators. The platform does not support connecting multiple output port to a single input port, but you could achieve similar effect using stream merge operator (https://github.com/apache/apex-malhar/blob/3ce83708f795b081d564be357a8333928154398e/library/src/main/java/com/datatorrent/lib/stream/StreamMerger.java) - Tushar. On Thu, Sep 1, 2016 at 10:37 PM, Jim <[email protected]> wrote: > Tushar, > > Funny that you described it that way, as that is exactly what I was thinking > about this morning. > > > So the flow would be: > > > > > Router Operator > > > > | > > > > Managed State Operator > > > | > > --------------------------------------------------------------------------------------------------------------------------------------- > | > | | > | > > General Acknowledgement Detailed Acknowledgement > Ship Notification Invoice > > | > | | > | > > --------------------------------------------------------------------------------------------------------------------------------------- > > | > > ------------------------------------------------------------------------------------------------------------------------------------------ > / each of the 4 operators at the end of > processing emits a record back to Managed State Operator / > > ---------------------------------------------------------------------- > -------------------------------------------------------------------- > > > In this scenario, would the managed state operator just have 1 input, > that all the other operators emit to, or would it need to have separate > inputs for each of the 5 operators that would be emitting to it? > > This is what you were describing too, correct? > > Thanks, > > Jim > > -----Original Message----- > From: Tushar Gosavi [mailto:[email protected]] > Sent: Thursday, September 1, 2016 11:49 AM > To: [email protected] > Subject: Re: HDHT question - looking for the datatorrent gurus! > > Hi Jim, > > Currently HDHT is accessible only to single operator in a DAG. Single HDHT > store can not be managed by two different operator at a time which could > cause metadata corruption. Theoretically HDHT bucket could be read from > multiple operators, but only one writer is allowed. > > In your case a stage in transaction is processed completely by different > operator and then only next stage can start. It could still be achieved by > using a single operator which manages HDHT state, and having a loop in DAG to > send completed transaction ids to sequencer. > > - Sequence operator will emit transaction to transaction processing operator. > - If it receives an out of order transaction it will note it down in HDHT. > - The processing operator will send completed transaction id on a port which > is connected back to sequence operator. > - On receiving data on this loopback port, sequence operator will update HDHT > and search for next transaction in order, which could be stored in HDHT and > will emit to next processing operator. > > - Tushar. > > > On Sat, Aug 27, 2016 at 1:31 AM, Jim <[email protected]> wrote: >> Good afternoon, >> >> >> >> I have an apex application where I may receive edi transactions, but >> sometimes they arrive out of order and I want to hold any out of >> sequence transactions till the correct time in the flow to process them. >> >> >> >> For example for a standard order, we will receive from the remote vendor: >> >> >> >> 1.) General Acknowledgement >> >> 2.) Detailed Acknowledgement >> >> 3.) Ship Notification >> >> 4.) Invoice >> >> >> >> They are supposed to be sent and received in that order. >> >> >> >> However sometimes vendors systems have problems, etc. so they send >> the all of these at the same time, and then we can receive them out of >> sequence. >> Data packets for these are very small, say from 1 to 512 bytes, and >> the only time they will be out of sequence, we will receive them very >> closely together. >> >> >> >> I am trying to think of the best way to do this in my datatorrent / >> Hadoop / yarn facilities, instead of creating a datatable in >> postgreSQl and using that. >> >> >> >> Can I create a flow that works like this (I am not sure if this makes >> sense, or is the best way to solve my problem, while keeping state, >> etc. maintained for all the operators): >> >> >> >> 1.) In the inbound transaction router, check the hdht store for the order >> number, if it doesn’t exist, this means it is a new order, if the >> transaction trying to process is the general acknowledgment, emit the >> data to the general acknowledgement operator; if it is not – store >> the transaction data into the correct bucket identifying the >> transaction is it for, as well as the next step to be the general >> acknowledgement in HDHT by order number. >> >> 2.) Say the next transaction is the ship notification, in the router, we >> would check the HDHT store, see this is not the next expected >> transaction (say it is supposed to be the detail acknowledgement), so >> we would just post the data for the ship notification into HDHT the store >> and say we are done. >> >> 3.) Say we now receive the detailed acknowledgement for an order whose >> next step IS the detailed acknowledgement, we would see this is the >> correct next transaction, emit it to the detailed acknowledgement >> operator, and update the HDHT store to show that the next transaction >> should be the ship notification. NOTE: we can’t emit the ship >> notification yet, till we have confirmed that the detailed ackkowledgment >> has been completed. >> >> 4.) In each of the 4 transaction operators at the end of the processing, >> we would update the HDHT store to show the next expected step, and if >> we already received data for the next expected step pull it from the >> HDHT store, and write the transaction into our SQS queue which is the >> input into the inbound transaction router at the beginning of the >> application, so it processes through the system. >> >> >> >> I believe HDHT can be used to pass data throughout an entire >> application, and is not limited to just a per operator basis, correct? >> >> >> >> Any comments / feedback? >> >> >> >> Thanks, >> >> >> >> Jim
