Aw: Re: Pull data from Redis every minute

Thu, 02 Jun 2016 01:46:04 -0700

Thank you! But how can I ensure that my spout pulls the actual values from Redis every minute from scratch? How does the spout work in such a case? Would it only pull values if there is a change in Redis or will they only be pulled once?
 
Would it be easier to do the lookup within the windowed bolt or with the tick tuple in a bolt instead of the spout?
 
Thank you and regards,
Daniela
 
Gesendet: Sonntag, 08. Mai 2016 um 19:44 Uhr
Von: "Spico Florin" <[email protected]>
An: "[email protected]" <[email protected]>
Betreff: Re: Pull data from Redis every minute
hi!
 for me it looks like proceesing the data in a specific window. you coul achive this by using the new feature in storm 1.0 namely window bolt. via spout you get the data thta you need and in the window bolt do the sum. be careful with the time thta you are using processing time versus event time. if your data has a timestsmp and you would like to use this field in your logic time then you need the event time and the notion of watermark. you coul find more info about this on 
i hope it helps.
florin

On Saturday, May 7, 2016, Erik Weathers <[email protected]> wrote:
If you need something to be done at a regular interval within Storm you might wanna leverage the "tick tuple" concept:
 
On Fri, May 6, 2016 at 11:53 PM, Daniela S <[email protected]> wrote:
Hi,
 
I would like to use Redis as a kind of cache for my active devices. So i receive a message over Kafka with an active device and store it in Redis. 
Now I would like to pull all active devices from Redis and to add a specific value to each device and to build a sum afterwards.
How can I ensure that the spout fetches the list of active devices e.g. every minute? Because the sum has to be built every minute from scratch, as the additional specific value changes every minute for every device.
 
Thank you in advance.
 
Regards,
Daniela

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