Andrew Purtell reassigned HBASE-18116:

    Assignee:     (was: Geoffrey Jacoby)

> Replication source in-memory accounting should not include bulk transfer 
> hfiles
> -------------------------------------------------------------------------------
>                 Key: HBASE-18116
>                 URL: https://issues.apache.org/jira/browse/HBASE-18116
>             Project: HBase
>          Issue Type: Bug
>          Components: Replication
>            Reporter: Andrew Purtell
>            Priority: Major
> In ReplicationSourceWALReaderThread we maintain a global quota on enqueued 
> replication work for preventing OOM by queuing up too many edits into queues 
> on heap. When calculating the size of a given replication queue entry, if it 
> has associated hfiles (is a bulk load to be replicated as a batch of hfiles), 
> we get the file sizes and include the sum. We then apply that result to the 
> quota. This isn't quite right. Those hfiles will be pulled by the sink as a 
> file copy, not pushed by the source. The cells in those files are not queued 
> in memory at the source and therefore shouldn't be counted against the quota.
> Related, the sum of the hfile sizes are also included when checking if queued 
> work exceeds the configured replication queue capacity, which is by default 
> 64 MB. HFiles are commonly much larger than this. 
> So what happens is when we encounter a bulk load replication entry typically 
> both the quota and capacity limits are exceeded, we break out of loops, and 
> send right away. What is transferred on the wire via HBase RPC though has 
> only a partial relationship to the calculation. 
> Depending how you look at it, it makes sense to factor hfile file sizes 
> against replication queue capacity limits. The sink will be occupied 
> transferring those files at the HDFS level. Anyway, this is how we have been 
> doing it and it is too late to change now. I do not however think it is 
> correct to apply hfile file sizes against a quota for in memory state on the 
> source. The source doesn't queue or even transfer those bytes. 
> Something I noticed while working on HBASE-18027.

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