Re: [HACKERS] Logical replication ApplyContext bloat

On 18/04/17 13:45, Stas Kelvich wrote:
> Hi,
> 
> currently logical replication worker uses ApplyContext to decode received data
> and that context is never freed during transaction processing. Hence if publication
> side is performing something like 10M row inserts in single transaction, then
> subscription worker will occupy more than 10G of ram (and can be killed by OOM).
> 
> Attached patch resets ApplyContext after each insert/update/delete/commit.
> I’ve tried to reset context only on each 100/1000/10000 value of CommandCounter,
> but didn’t spotted any measurable difference in speed.
> 
> Problem spotted by Mikhail Shurutov.
> 

Hmm we also do replication protocol handling inside the ApplyContext
(LogicalRepApplyLoop), are you sure this change is safe in that regard?

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