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Alexey Romanenko edited comment on BEAM-9439 at 3/30/20, 4:41 PM:
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[~pawel.kaczmarczyk] I think now I see why {{getTotalBacklogBytes()}} was 
implemented, thanks.
{quote}As I understand, to fix getTotalBacklogBytes() we would need the 
watermark of the whole stream, not just current split, right?
{quote}
I think so if we can't get the number of bytes per shard and implement 
\{{getSplitBacklogBytes(}}

In the same time, I doubt that implementation based on Enhanced Shard-level 
Metrics should be default since, as you mentioned, it will charge additionally. 
Perhaps, it could be an alternative solution for those who wants to use it.


was (Author: aromanenko):
[~pawel.kaczmarczyk] I think now I see why {{getTotalBacklogBytes()}} was 
implemented, thanks. 
bq. As I understand, to fix getTotalBacklogBytes() we would need the watermark 
of the whole stream, not just current split, right?

I think so if we can't get the number of bytes per shard.

In the same time, I doubt that implementation based on  Enhanced Shard-level 
Metrics should be default since, as you mentioned, it will charge additionally. 
Perhaps, it could be an alternative solution for those who wants to use it. 

> KinesisReader does not report correct backlog statistics 
> ---------------------------------------------------------
>
>                 Key: BEAM-9439
>                 URL: https://issues.apache.org/jira/browse/BEAM-9439
>             Project: Beam
>          Issue Type: Bug
>          Components: io-java-kinesis
>            Reporter: Sam Whittle
>            Priority: Major
>
> The KinesisReader implementing KinesisIO reports backlog by implementing the
> UnboundedSource.getTotalBacklogBytes()
> method as opposed to the
> UnboundedSource.getSplitBacklogBytes()
> This value is supposed to represent the total backlog across all shards.  
> This function is implemented by calling 
> SimplifiedKinesisClient.getBacklogBytes with the watermark of the kinesis 
> shards managed within the UnboundedReader instance.  As this watermark may be 
> further ahead than the watermark across all shards, this may miss backlog 
> bytes.
> An additional concern is that the watermark is calculated using a 
> WatermarkPolicy, which means that the watermark may be inconsistent to the 
> kinesis timestamp for querying backlog.



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