Hi, I’m not sure how much effort we will be willing to invest in the existing batch stack. We are currently focusing on the support of bounded DataStreams (already done in Blink and will be merged to Flink soon) and unifing batch & stream under DataStream API.
Piotrek > On 23 Jan 2019, at 04:45, Bo WANG <wbeaglewatc...@gmail.com> wrote: > > Hi all, > > When running the batch WordCount example, I configured the job execution > mode > as BATCH_FORCED, and failover-strategy as region, I manually injected some > errors to let the execution fail in different phases. In some cases, the > job could > recovery from failover and became succeed, but in some cases, the job > retried > several times and failed. > > Example: > - If the failure occurred before task read data, e.g., failed before > invokable.invoke() in Task.java, failover could succeed. > - If the failure occurred after task having read data, failover did not > work. > > Problem diagnose: > Running the example described before, each ExecutionVertex is defined as > a restart region, and the ResultPartitionType between executions is > BLOCKING. > Thus, SpillableSubpartition and SpillableSubpartitionView are used to > write/read > shuffle data, and data blocks are described as BufferConsumers stored in a > list > called buffers, when task requires input data from > SpillableSubpartitionView, > BufferConsumers are REMOVED from buffers. Thus, when failures occurred > after having read data, some BufferConsumers have already released. > Although tasks retried, the input data is incomplete. > > Fix Proposal: > - BufferConsumer should not be removed from buffers until the consumed > ExecutionVertex is terminal. > - SpillableSubpartition should not be released until the consumed > ExecutionVertex is terminal. > - SpillableSubpartition could creates multi SpillableSubpartitionViews, > each of which is corresponding to a ExecutionAttempt. > > Best, > Bo
