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From Stefan Richter <s.rich...@data-artisans.com>
Subject Re: Incremental RocksDB checkpointing
Date Fri, 01 Dec 2017 17:33:35 GMT
Ok, I think all I can comment about this case was already in the previous email. Incremental
checkpoints are designed with large state in mind and you cannot extrapolate this observation
to e.g. 1 million keys, so I think everything is working just fine.

> Am 01.12.2017 um 18:22 schrieb vijayakumar palaniappan <vijayakumarpl@gmail.com>:
> 
> I observed the job for 18 hrs, it went from 118kb to 1.10MB.
> 
> I am using version 1.3.0 flink
> 
> On Fri, Dec 1, 2017 at 11:39 AM, Stefan Richter <s.richter@data-artisans.com <mailto:s.richter@data-artisans.com>>
wrote:
> Maybe one more question: is the size always increasing, or will it also reduce eventually?
Over what period of time did you observe growth? From the way how RocksDB works, it does persist
updates in a way that is sometimes closer to a log than in-place updates. So it is perfectly
possible that you can observe a growing state for some time. Eventually, if the state reaches
a critical mass, RocksDB will consolidate and prune the written state and that is the time
when you should also observe a drop in size.
> 
> From what it seems, you use case is working with a very small state, so if this is not
just a test you should reconsider if this is the right use-case for a) incremental checkpoints
and b) RocksDB at all.
> 
> > Am 01.12.2017 um 16:34 schrieb vijayakumar palaniappan <vijayakumarpl@gmail.com
<mailto:vijayakumarpl@gmail.com>>:
> >
> > I have simple event time window aggregate count function with incremental checkpointing
enabled. The checkpoint size keeps increasing over a period of time, even though my input
data has a single key and data is flowing at a constant rate.
> >
> > When i turn off incremental checkpointing, checkpoint size remains constant?
> >
> > Is there are any switches i need to enable or is this a bug?
> >
> > --
> > Thanks,
> > -Vijay
> 
> 
> 
> 
> -- 
> Thanks,
> -Vijay


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