Hi Pengfei Li:
I have not encountered this in production yet, I just check the code
and found this is not the same with no userkey suppilied.
I checked the MapSerializer and found the serialized format for each Map.entry
is [key – isValueNull(boolean) – value]. And When boolean is serialized, byte
1 is for true and byte 0 is for false. If we change the serialized format to
[key-flag(byte)-value] , That is we do not view the byte as Boolean, just pure
byte, I think we can migrate the key too:
Flag == 0, value is null.
Flag == 1, the key is in old format.
Flag == 2, we can use this to write new key.
从 Windows 版邮件发送
发件人: Pengfei Li
发送时间: 2021年11月25日 18:17
收件人: dev@flink.apache.org
主题: Re: RocksDBMapState get the binary key bytes
This problem is tracked in FLINK-11141
<https://issues.apache.org/jira/browse/FLINK-11141>, but there is not a
solution yet considering the state compatibility. Have you encountered the
problem in production?
Zen4YYDS <gafam...@163.com> 于2021年11月25日周四 下午3:30写道：
> Hi devs:
>
> Using RocksDB, when key and namespace both have variable binary
> length, to prevent [key, namespace] have equal binary number, we add key
> length and namespace length after key and namespace respectively. Then the
> format is:
> Keygroup – key -keyLength– namespace-namespaceLenth
>
> Then what about we use a fixed length key and variable length
> namespace and userkey. In current implement, I found the binary key format
> is as below:
>
> Keygroup – key – namespace- userkey
>
> Think about following situation, I think we may get the same value for
> different [namespace, userkey]. or I get something wrong?
>
> Keygroup key namespace userkey
> 1 1 11 1
> 1 1 1 11
>
>
> 从 Windows 版邮件发送
>
>
