Re: Logical replication 'invalid memory alloc request size 1585837200' after upgrading to 17.5

On Thu, 29 May 2025 at 22:57, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> > I agree that chances are much lower than current if txn->invalidations
> > doesn't contain invalidations from other transactions, but it is not
> > clear what exactly you are trying to advocate by it. Are you trying to
> > advocate that we should maintain a member similar to txn->invalidation
> > (say txn->distributed_invals) instead of a queue?
>
> Yes, because I guess it's much simpler. I think it would not be a good
> idea to introduce a new concept of accounting the memory usage of the
> distributed inval messages too and serializing them, at least on back
> branches. I think that In case where the txn->distriubted_inval is
> about to overflow (not has to be 1GB) we can invalidate all caches
> instread.

To identify overflow scenarios, I’m considering the following options:
a) Introduce a new txn_flags value, such as RBTXN_INVAL_ALL_CACHE, to
explicitly mark transactions that require full cache invalidation.
b) Add a dedicated parameter to indicate an overflow scenario.
c) setting the newly added nentries_distr to -1, to indicate an
overflow scenario.

Do you have any preference or thoughts on which of these approaches
would be cleaner?

Regards,
Vignesh