[pgpool-general: 5474] how can i force selection of primary backend?

[PVY]

Hello.

Is there any way I can specify particular backend to be a primary one, so  that  write requests  are routed to it?
In short: out of three nodes two respond with "f" to "select pg_is_in_recovery();" request. 
But I want only one of them, #0, to be considered master by pgool.

I'll try to explain what I mean below.

My setup:
pgpool-3.6.2
three PgSQL servers:
   - master on amazon RDS
   - streaming replica on amazon RDS
   - replica  in  amazon ec2 instance created with Bucardo. It is the same server where pgpool runs.

No (automatic) failover  of  master  is  planned,  this is the description of backends in pgpool.conf:
###################################################################################
#aws rds master
backend_hostname0 = 'aws-master-ip'
backend_port0 = 5432
backend_weight0 = 20
backend_flag0 = 'DISALLOW_TO_FAILOVER'

#aws rds slave, postgresql streaming replication
backend_hostname1= 'aws-slave-ip'
backend_port1 = 5432
backend_weight1 = 40
backend_flag1 = 'ALLOW_TO_FAILOVER'

#aws ec2 slave, created with Bucardo
backend_hostname2= '127.0.0.1'
backend_port2 = 5433
backend_weight2 = 40
backend_flag2 = 'ALLOW_TO_FAILOVER'

###################################################################################

Since  replica  created with bucardo is not, from PgSQL point of view, running in replication mode, I set 
sr_check_period = 0. 
However sr_check_user, _password and _database variables are set with valid values.
Right  now  "show nodes_pool;"  shows  that all is as intended - the real
master server is marked as primary:

 node_id |   hostname    | port | status | lb_weight |  role   | select_cnt | load_balance_node | replication_delay
---------+-----------------------------------------------------------------+------+--------+-----------+---------+------------+-------------------+-------------------
 0       | aws-master-ip | 5432 | up     | 0.200000  | primary | 83327      | false             | 0
 1       | aws-slave-ip  | 5432 | up     | 0.400000  | standby | 105534     | true              | 0
 2       | 127.0.0.1     | 5433 | up     | 0.400000  | standby | 112791     | false             | 0

However, I'm worried - the node #2 responds with "f" to the select pg_is_in_recovery(); request. Because, as I stated before, this postgresql server does not consider itself to be a replicating slave. There is no way to attach a streaming replica slave to a master server running on amazon rds, therefore I have to use this complex scheme with Bucardo. I'm afraid that after pgpool restarts it may select node #2 as primary. 

I was thinking of leaving sr_check_user, _password and _database values blank so that pgpool would always use node number 0 as primary (as it was stated here: http://www.sraoss.jp/pipermail/pgpool-general/2014-February/002603.html ) but it brings other problems: after a slave failover I've got a lot of pgpool zombie processes and my log was flooded with these messages:
pgpool[24961]: [338591-1] ERROR:  failed to authenticate
pgpool[24961]: [338591-2] DETAIL:  no PostgreSQL user name specified in startup packet

So, to summarize: can i forcefully configure node #0 to be my primary one? 

Thank you.

-- 
 Pavel                          mailto:balroga3 at yandex.ru