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

On Tue, 3 Jun 2025 at 12:37, vignesh C <vignesh21@gmail.com> wrote:
>
> On Mon, 2 Jun 2025 at 22:49, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> >
> > Thank you for updating the patch. Here are some review comments:
> >
> > +   req_mem_size = sizeof(SharedInvalidationMessage) *
> > (txn->ninvalidations_distr + nmsgs);
> > +
> > +   /*
> > +    * If the number of invalidation messages is larger than 8MB, it's more
> > +    * efficient to invalidate the entire cache rather than processing each
> > +    * message individually.
> > +    */
> > +   if (req_mem_size > (8 * 1024 * 1024) || rbtxn_inval_all_cache(txn))
> >
> > It's better to define the maximum number of distributed inval messages
> > per transaction as a macro instead of calculating the memory size
> > every time.
>
> Modified
>
> > ---
> > +static void
> > +ReorderBufferAddInvalidationsCommon(ReorderBuffer *rb, TransactionId xid,
> > +                                   XLogRecPtr lsn, Size nmsgs,
> > +                                   SharedInvalidationMessage *msgs,
> > +                                   ReorderBufferTXN *txn,
> > +                                   bool for_inval)
> >
> > This function is quite confusing to me. For instance,
> > ReorderBufferAddDistributedInvalidations() needs to call this function
> > with for_inval=false in spite of adding inval messages actually. Also,
> > the following condition seems not intuisive but there is no comment:
> >
> >     if (!for_inval || (for_inval && !rbtxn_inval_all_cache(txn)))
> >
> > Instead of having ReorderBufferAddInvalidationsCommon(), I think we
> > can have a function say ReorderBufferQueueInvalidations() where we
> > enqueue the given inval messages as a
> > REORDER_BUFFER_CHANGE_INVALIDATION change.
> > ReorderBufferAddInvalidations() adds inval messages to
> > txn->invalidations and calls that function, while
> > ReorderBufferQueueInvalidations() adds inval messages to
> > txn->distributed_ivnalidations and calls that function if the array is
> > not full.
>
> Modified
>
> > BTW if we need to invalidate all accumulated caches at the end of
> > transaction replay anyway, we don't need to add inval messages to
> > txn->invalidations once txn->distributed_invalidations gets full?
>
> yes, no need to add invalidation messages to txn->invalidation once
> RBTXN_INVAL_ALL_CACHE is set. This is handled now.
>
> The attached v9 version patch has the changes for the same.

I've posted the patch for the master branch only. I'll submit the
back-branch patches once this patch is in a committable state.

Regards,
Vignesh