Re: [HACKERS] Server Crashes if try to provide slot_name='none' atthe time of creating subscription.

On 05/16/2017 06:35 AM, Masahiko Sawada wrote:
> I've updated Kuntal's patch, added regression test for option
> combination and updated documentation.
While testing the patch - I  found that after dump/restore , we are 
getting an error in the log file once we enable the subscription

\\create subscription

postgres=# CREATE SUBSCRIPTION m1 CONNECTION 'dbname=postgres port=5000 
' PUBLICATION qdd WITH (slot_name='none');
NOTICE:  synchronized table states
CREATE SUBSCRIPTION

\\take the dump
[centos@centos-cpula bin]$ ./pg_dump -Fp  -p 9000 postgres > /tmp/d.c
\\check the syntax
[centos@centos-cpula bin]$ cat /tmp/d.c |grep 'create subsc*' -i
CREATE SUBSCRIPTION m1 CONNECTION 'dbname=postgres port=5000 ' 
PUBLICATION qdd WITH (connect = false, slot_name = '');
\\execute this same syntax against a new database
postgres=# create database  test;
CREATE DATABASE
postgres=# \c test
You are now connected to database "test" as user "centos".
test=# CREATE SUBSCRIPTION m1 CONNECTION 'dbname=postgres port=5000 ' 
PUBLICATION qdd WITH (connect = false, slot_name = '');
WARNING:  tables were not subscribed, you will have to run ALTER 
SUBSCRIPTION ... REFRESH PUBLICATION to subscribe the tables
CREATE SUBSCRIPTION

test=# alter subscription m1 refresh publication ;
ERROR:  ALTER SUBSCRIPTION ... REFRESH is not allowed for disabled 
subscriptions
test=# alter subscription m1 enable ;
ALTER SUBSCRIPTION

Check the message in  log file

017-05-16 14:04:48.373 BST [18219] LOG:  logical replication apply for 
subscription m1 started
2017-05-16 14:04:48.381 BST [18219] ERROR:  could not start WAL 
streaming: ERROR:  replication slot name "" is too short
2017-05-16 14:04:48.382 BST [17843] LOG:  worker process: logical 
replication worker for subscription 16386 (PID 18219) exited with exit 
code 1
2017-05-16 14:04:53.388 BST [17850] LOG:  starting logical replication 
worker for subscription "m1"
2017-05-16 14:04:53.396 BST [18224] LOG:  logical replication apply for 
subscription m1 started
2017-05-16 14:04:53.403 BST [18224] ERROR:  could not start WAL 
streaming: ERROR:  replication slot name "" is too short

Is this error message (ERROR:  replication slot name "" is too short ) 
is expected now ?

-- 
regards,tushar
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