There's a passing reference to it in the 1.2 docs but we removed it to discourage use.
https://nightlies.apache.org/flink/flink-docs-release-1.2/dev/stream/state.html#raw-and-managed-state On Sat, Mar 12, 2022 at 2:50 AM Christopher Gustafson <chr...@kth.se> wrote: > Hi, > > > Thanks for the explanation, I had not heard about the Raw State before, > and it sounds like that is not surprising if it is rarely used, and doesn't > seem to be included in the latest versions of the documentation. Is there > perhaps some older version of the documentation you could point me to where > I can see how Raw state can be used in Flink? > > > Best Regards, > > Christopher Gustafson > ------------------------------ > *Från:* Seth Wiesman <sjwies...@gmail.com> > *Skickat:* den 11 mars 2022 17:57:21 > *Till:* Christopher Gustafson > *Kopia:* user@flink.apache.org > *Ämne:* Re: Checkpointing in StateFun > > I assume you are talking about the checkpointing in the feedback package? > > StateFun only relies on Flink checkpointing for fault tolerance. All state > is stored in standard checkpoint / savepoints and can be used to restore > from failure, upgrade a job, rescale, etc. Just like any other snapshot. > > StateFun internally relies on a form of streaming iteration. The feedback > package contains the code for that iteration which sends records back > upstream. To ensure exactly-once semantics, in-flight records on the > feedback edge need to be stored in the snapshot. It does so through Flinks > raw keyed state abstraction. This is the same thing state backends use > under the hood to snapshot out your keyed state in any rich function. > > Raw keyed state has been a stable part of Flinks API forever, but is > rarely seen in user code. I often describe the statefun runtime to people > as the world's most complex datastream application; you will find advanced > usage patterns most people have not seen, but nothing that isn't well > supported by Flink. > > Seth > > On Fri, Mar 11, 2022 at 2:24 AM Christopher Gustafson <chr...@kth.se> > wrote: > >> Hi, >> >> >> I am doing some experiments with StateFun and different Flink state >> backends. I was looking through the StateFun source code and saw that it is >> doing some own logic when it comes to checkpointing. My initial >> understanding was that checkpointing was implicitly leveraged with Flink. I >> did not find a lot of documentation about this, so I am asking if you could >> provide a description of how checkpointing works in StateFun, and how it is >> different from regular Flink checkpointing? >> >> >> Thanks in advance, >> >> Christopher Gustafson >> >
