Re: [HACKERS] Error while creating subscription when server isrunning in single user mode

On Wed, May 31, 2017 at 7:01 AM, Dilip Kumar <dilipbalaut@gmail.com> wrote:
> On Wed, May 31, 2017 at 7:54 AM, tushar <tushar.ahuja@enterprisedb.com> wrote:
>> centos@centos-cpula bin]$ ./postgres --single postgres -D m1data
>> PostgreSQL stand-alone backend 10beta1
>> backend> create subscription sub connection 'dbname=postgres port=5433
>> user=centos' publication p with (create_slot=0,enabled=off);
>> 2017-05-31 12:53:09.318 BST [10469] LOG:  statement: create subscription sub
>> connection 'dbname=postgres port=5433 user=centos' publication p with
>> (create_slot=0,enabled=off);
>>
>> 2017-05-31 12:53:09.326 BST [10469] ERROR:  epoll_ctl() failed: Bad file
>> descriptor
>
> IMHO, In single user mode, it can not support replication (it can not
> have background WALReciver task). However, I believe there should be a
> proper error if the above statement is correct.

Yeah, see 0e0f43d6 for example. A simple fix is to look at
IsUnderPostmaster when creating, altering or dropping a subscription
in subscriptioncmds.c.
-- 
Michael