>> "User was holding shared buffer pin for too long" sounds unusual to
>> me. Is this a bug? PostgreSQL version is 10.1 according to the user.
> Sounds normal to me. Maybe the message could use some work, but this
> is how hot standby works: if max_standby_archive_delay or
> max_standby_streaming_delay expires, whatever is blocking recovery
> gets blasted out of the way.
I didn't know that recovery conflict could happen even with buffer
pin. I should have examined the source code first. Sorry for noise.
SRA OSS, Inc. Japan