Re: [BUG] Crash of logical replica with trigger.

On Wed, Sep 28, 2022 at 10:33 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> Hi,
>
> On Mon, Aug 15, 2022 at 4:48 AM Anton A. Melnikov <aamelnikov(at)inbox(dot)ru> wrote:
> >
> > Hello!
> >
> > There is a crash during logical replication.
> >
> > Reproduction on current master:
> > A) on master (wal_level = logical): create table rul_rule_set that will be replicated:
> > CREATE TABLE public.rul_rule_set (id smallint NOT NULL, description text, stage_id integer,
> > condition text, condition_compiled text);
> > ALTER TABLE ONLY public.rul_rule_set ADD CONSTRAINT rul_rule_set_pkey PRIMARY KEY (id);
> > CREATE PUBLICATION test_pub FOR TABLE rul_rule_set;
> >
> > B) on replica
> > 1. Create tables doc_attribute and rul_rule_set for incoming changes:
> > CREATE TABLE public.doc_attribute (id integer NOT NULL, attr_name text, attr_desc text, attr_type text,
> > attr_order integer, is_system boolean, used_by_slice boolean);
> > INSERT INTO doc_attribute VALUES ('1','name','Имя','text','1','t','t');
> > CREATE TABLE public.rul_rule_set (id smallint NOT NULL, description text, stage_id integer,
> > condition text, condition_compiled text);
> > ALTER TABLE ONLY public.doc_attribute ADD CONSTRAINT doc_attribute_pkey PRIMARY KEY (id);
> > ALTER TABLE ONLY public.rul_rule_set ADD CONSTRAINT rul_rule_set_pkey PRIMARY KEY (id);
> >
> > 2.Create procedure and trigger that will be fired on lines inserting into the rul_rule_set table:
> > Execute trigger.sql attached.
> >
> > 3. Create suscription:
> > CREATE SUBSCRIPTION test_sub CONNECTION 'port=5116 user=postgres dbname=postgres' PUBLICATION test_pub;
> >
> > C) on master: insert row in table rul_rule_set:
> > INSERT INTO rul_rule_set VALUES ('1', 'name','1','age','true');
> >
> > The replica will crash with:
> > TRAP: FailedAssertion("ActivePortal && ActivePortal->status == PORTAL_ACTIVE", File: "pg_proc.c", Line: 1038, PID: 310502)
> >
> > as ActivePortal is NULL because logical replication worker was forked before any active command.
>
> Right. This is because the logical replication workers (apply worker
> and tablesync worker) don't have a Portal.
>
> >
> > The backtrace is attached.
> >
> > I thought to pass the text of the request as a parameter, but most likely, it will be wrong.
> > Please suggest the best way to solve this problem, would be very grateful.
>
> In function_parse_error_transpose(), I think that we don't need the
> query text in logical replication worker cases since they don't
> execute SQL query.
>
> I've attached the patch to fix it. The patch also includes a minimal
> TAP test for this case.

I've registered this issue to the next CF so as not to forget.

Regards,

--
Masahiko Sawada
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com