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From Mich Talebzadeh <mich.talebza...@gmail.com>
Subject Re: How big the spark stream window could be ?
Date Mon, 09 May 2016 07:01:57 GMT
ok terms for Spark Streaming

"Batch interval" is the basic interval at which the system with receive the
data in batches.
This is the interval set when creating a StreamingContext. For example, if
you set the batch interval as 300 seconds, then any input DStream will
generate RDDs of received data at 300 seconds intervals.
A window operator is defined by two parameters -
- WindowDuration / WindowsLength - the length of the window
- SlideDuration / SlidingInterval - the interval at which the window will
slide or move forward


Ok so your batch interval is 5 minutes. That is the rate messages are
coming in from the source.

Then you have these two params

// window length - The duration of the window below that must be multiple
of batch interval n in = > StreamingContext(sparkConf, Seconds(n))
val windowLength = x =  m * n
// sliding interval - The interval at which the window operation is
performed in other words data is collected within this "previous interval'
val slidingInterval =  y l x/y = even number

Both the window length and the slidingInterval duration must be multiples
of the batch interval, as received data is divided into batches of duration
"batch interval".

If you want to collect 1 hour data then windowLength =  12 * 5 * 60 seconds
If you want to collect 24 hour data then windowLength =  24 * 12 * 5 * 60

You sliding window should be set to batch interval = 5 * 60 seconds. In
other words that where the aggregates and summaries come for your report.

What is your data source here?

HTH


Dr Mich Talebzadeh



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On 9 May 2016 at 04:19, kramer2009@126.com <kramer2009@126.com> wrote:

> We have some stream data need to be calculated and considering use spark
> stream to do it.
>
> We need to generate three kinds of reports. The reports are based on
>
> 1. The last 5 minutes data
> 2. The last 1 hour data
> 3. The last 24 hour data
>
> The frequency of reports is 5 minutes.
>
> After reading the docs, the most obvious way to solve this seems to set up
> a
> spark stream with 5 minutes interval and two window which are 1 hour and 1
> day.
>
>
> But I am worrying that if the window is too big for one day and one hour. I
> do not have much experience on spark stream, so what is the window length
> in
> your environment?
>
> Any official docs talking about this?
>
>
>
>
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