Hi Stephan,
Thanks for your response. I shall try switching to the fully Async mode and see.
On another note, is there any option available to configure compaction 
capabilities using the default checkpointing mode? Thanks.

From: Stephan Ewen
Reply-To: "user@flink.apache.org<mailto:user@flink.apache.org>"
Date: Monday, December 19, 2016 at 11:51 AM
To: "user@flink.apache.org<mailto:user@flink.apache.org>"
Subject: Re: Reg Checkpoint size using RocksDb

Hi!

If you use the default checkpoint mode, Flink will checkpoint the current 
RocksDB instance. It may be that there simply has not been a compaction in 
RocksDB when checkpointing, so the checkpoint contains some "old data" as well.

If you switch to the "fully async" mode, it should always only checkpoint the 
latest state of RocksDB.

Best,
Stephan


On Mon, Dec 19, 2016 at 10:47 AM, Anirudh Mallem 
<anirudh.mal...@247-inc.com<mailto:anirudh.mal...@247-inc.com>> wrote:
Hi,
I was experimenting with using RocksDb as the state backend for my job and to 
test its behavior I modified the socket word count program to store states. I 
also wrote a RichMapFunction which stores the states as a ValueState with 
default value as null.
What the job does basically is, for every word received if the current state is 
null then it updates the state with a fixed value say “abc” and in case the 
state is nonNull then it is cleared.
So ideally if my input stream has the word “foo” twice then the corresponding 
state is first set to “abc” and then cleared at the second “foo”. I see that 
this behavior is occurring as expected but the checkpointed size keeps 
increasing! Is this expected? I believe the checkpointed size as shown on the 
dashboard should decrease when some of the states are cleared right?
In this case if each of the “foo” word come in successive checkpointing 
intervals then we should observe rise and one fall in the checkpointing size 
right? I see the checkpointed size is increasing in both cases!!!

Any ideas as to what is happening here? My checkpoint duration is 5 secs. 
Thanks.

Regards,
Anirudh



Reply via email to