Re: TRAP: FailedAssertion("prev_first_lsn < cur_txn->first_lsn", File: "reorderbuffer.c", Line: 927, PID: 568639)

On Tue, Oct 18, 2022 at 1:45 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> >
> > I think because the test case proposed needs all three changes, we can
> > push the change-1 without a test case and then as a second patch have
> > change-2 for HEAD and change-3 for back branches with the test case.
> > Do you have any other ideas to proceed here?
>
> I found another test case that causes the assertion failure at
> "Assert(!needs_snapshot || needs_timetravel);" on all branches. I've
> attached the patch for the test case. In this test case, I modified a
> user-catalog table instead of system-catalog table. That way, we don't
> generate invalidation messages while generating NEW_CID records. As a
> result, we mark only the subtransactions as containing catalog change
> and don't make association between top-level and sub transactions. The
> assertion failure happens on all supported branches. If we need to fix
> this (I believe so), Change-2 needs to be backpatched to all supported
> branches.
>
> There are three changes as Amit mentioned, and regarding the test
> case, we have three test cases I've attached: truncate_testcase.patch,
> analyze_testcase.patch, uesr_catalog_testcase.patch. The relationship
> between assertion failures and test cases are very complex. I could
> not find any test case to cause only one assertion failure on all
> branches. One idea to proceed is:
>
> Patch-1 includes Change-1 and is applied to all branches.
>
> Patch-2 includes Change-2 and the user_catalog test case, and is
> applied to all branches.
>
> Patch-3 includes Change-3 and the truncate test case (or the analyze
> test case), and is applied to v14 and v15 (also till v11 if we
> prefer).
>
> The patch-1 doesn't include any test case but the user_catalog test
> case can test both Change-1 and Change-2 on all branches.
>

I was wondering if it makes sense to commit both Change-1 and Change-2
together as one patch? Both assertions are caused by a single test
case and are related to the general problem that the association of
top and sub transaction is only guaranteed to be formed before we
decode transaction changes. Also, it would be good to fix the problem
with a test case that can cause it. What do you think?

-- 
With Regards,
Amit Kapila.