wal_level = hot_standby
max_wal_senders = 20
checkpoint_segments = 8
wal_keep_segments = 8

wal_level = hot_standby
max_wal_senders = 3
checkpoint_segments = 8
wal_keep_segments = 8
hot_standby = on

standby_mode = 'on'
primary_conninfo = 'host=<IP of master> port=5432 user=replicator password=xxxx sslmode=require'
trigger_file = '/tmp/postgresql.trigger'

2017-05-04 01:16:51 UTC [9608-1] FATAL:  could not connect to the primary server: FATAL:  sorry, too many clients already
2017-05-04 01:16:57 UTC [10807-1] FATAL:  could not connect to the primary server: FATAL:  sorry, too many clients already
2017-05-04 01:17:02 UTC [12022-1] FATAL:  could not connect to the primary server: FATAL:  sorry, too many clients already
2017-05-04 01:17:06 UTC [13217-1] FATAL:  could not connect to the primary server: FATAL:  remaining connection slots are reserved for non-replication superuser connections
...

2017-05-04 08:44:14 UTC [24850-1] replicator@[unknown] ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-05-04 08:44:19 UTC [25958-1] replicator@[unknown] ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-05-04 08:44:24 UTC [27063-1] replicator@[unknown] ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-05-04 08:44:29 UTC [28144-1] replicator@[unknown] ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-05-04 08:44:34 UTC [29227-1] replicator@[unknown] ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-05-04 08:44:39 UTC [30316-1] replicator@[unknown] ERROR:  requested WAL segment 000000010000003500000014 has already been removed
...

2017-04-30 11:26:22 UTC [28474-1] LOG:  started streaming WAL from primary at 35/14000000 on timeline 1
2017-04-30 11:26:22 UTC [28474-2] FATAL:  could not receive data from WAL stream: ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-04-30 11:26:26 UTC [29328-1] LOG:  started streaming WAL from primary at 35/14000000 on timeline 1
2017-04-30 11:26:26 UTC [29328-2] FATAL:  could not receive data from WAL stream: ERROR:  requested WAL segment 000000010000003500000014 has already been removed
2017-04-30 11:26:31 UTC [30394-1] LOG:  started streaming WAL from primary at 35/14000000 on timeline 1
2017-04-30 11:26:31 UTC [30394-2] FATAL:  could not receive data from WAL stream: ERROR:  requested WAL segment 000000010000003500000014 has already been removed
...