Re: Queryable State

Posted by Fabian Hueske-2 on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Queryable-State-tp18973p18993.html

Hi Vishal,

In general, Queryable State should be ready to use.
There are a few things to consider though:

- State queries are not synchronized with the application code, i.e., they can happen at the same time. Therefore, the Flink application should not modify objects that have been put into or read from the state if you are not using the RocksDBStatebackend (which creates copies by deserialization).

- State will be rolled back after a failure. Hence, you can read writes that are not "committed by a checkpoint".

@Kostas, did I forget something?

Best, Fabian

2018-03-18 16:50 GMT+01:00 Vishal Santoshi <[hidden email]>:

To be more precise, is anything thing similar to https://engineering.linkedin.com/blog/2018/03/air-traffic-controller--member-first-notifications-at-linkedin . done in Samza, can be replicated with production level guarantees with Flink Queryable state ( as it stands currently version 1.5 )  ? 

On Fri, Mar 16, 2018 at 5:10 PM, Vishal Santoshi <[hidden email]> wrote:

We are making few decisions on use cases where  Queryable state is a natural fit https://ci.apache.org/projects/flink/flink-docs-release-1.4/dev/stream/state/queryable_state.html

Is Queryable state production ready ? We will go to 1.5 flnk if that helps to make the case for the usage.