Great! That's what I gathered from the thread titled "Serial batching with
Spark Streaming", but thanks for confirming this again.

On 6 July 2015 at 15:31, Tathagata Das <t...@databricks.com> wrote:

> Yes, RDD of batch t+1 will be processed only after RDD of batch t has been
> processed. Unless there are errors where the batch completely fails to get
> processed, in which case the point is moot. Just reinforcing the concept
> further.
> Additional information: This is true in the default configuration. You may
> find references to an undocumented hidden configuration called
> "spark.streaming.concurrentJobs" elsewhere in the mailing list. Setting
> that to more than 1 to get more concurrency (between output ops) *breaks*
> the above guarantee.
>
> TD
>
> On Sat, Jul 4, 2015 at 6:53 AM, Michal Čizmazia <mici...@gmail.com> wrote:
>
>> I had a similar inquiry, copied below.
>>
>> I was also looking into making an SQS Receiver reliable:
>>
>> http://stackoverflow.com/questions/30809975/reliable-sqs-receiver-for-spark-streaming
>>
>> Hope this helps.
>>
>> ---------- Forwarded message ----------
>> From: Tathagata Das <t...@databricks.com>
>> Date: 20 June 2015 at 17:21
>> Subject: Re: Serial batching with Spark Streaming
>> To: Michal Čizmazia <mici...@gmail.com>
>> Cc: Binh Nguyen Van <binhn...@gmail.com>, user <user@spark.apache.org>
>>
>>
>> No it does not. By default, only after all the retries etc related to
>> batch X is done, then batch X+1 will be started.
>>
>> Yes, one RDD per batch per DStream. However, the RDD could be a union of
>> multiple RDDs (e.g. RDDs generated by windowed DStream, or unioned
>> DStream).
>>
>> TD
>>
>> On Fri, Jun 19, 2015 at 3:16 PM, Michal Čizmazia <mici...@gmail.com>
>> wrote:
>> Thanks Tathagata!
>>
>> I will use *foreachRDD*/*foreachPartition*() instead of *trasform*()
>> then.
>>
>> Does the default scheduler initiate the execution of the *batch X+1*
>> after the *batch X* even if tasks for the* batch X *need to be *retried
>> due to failures*? If not, please could you suggest workarounds and point
>> me to the code?
>>
>> One more thing was not 100% clear to me from the documentation: Is there
>> exactly *1 RDD* published *per a batch interval* in a DStream?
>>
>>
>> On 3 July 2015 at 22:12, khaledh <khal...@gmail.com> wrote:
>>
>>> I'm writing a Spark Streaming application that uses RabbitMQ to consume
>>> events. One feature of RabbitMQ that I intend to make use of is bulk ack
>>> of
>>> messages, i.e. no need to ack one-by-one, but only ack the last event in
>>> a
>>> batch and that would ack the entire batch.
>>>
>>> Before I commit to doing so, I'd like to know if Spark Streaming always
>>> processes RDDs in the same order they arrive in, i.e. if RDD1 arrives
>>> before
>>> RDD2, is it true that RDD2 will never be scheduled/processed before RDD1
>>> is
>>> finished?
>>>
>>> This is crucial to the ack logic, since if RDD2 can be potentially
>>> processed
>>> while RDD1 is still being processed, then if I ack the the last event in
>>> RDD2 that would also ack all events in RDD1, even though they may have
>>> not
>>> been completely processed yet.
>>>
>>>
>>>
>>> --
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>>
>

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