global
	log /dev/log local0
	maxconn 5000
	stats socket /run/haproxy/admin.sock mode 660 level admin
 
defaults
	mode tcp
	timeout connect 5s
	timeout client  30s
	timeout server  30s
	timeout check 5s
	log global
	option tcplog
	retries 3
 

listen stats
	bind 0.0.0.0:8404
	mode http
	stats enable
	stats uri /stats
	stats refresh 10s
	stats auth admin:admin

# ============================
# SCHREIBZUGRIFFE (nur Leader/Primary)
# ============================
frontend postgres_write
	#bind *:5432
	bind *:5433				# Port zum schreiben
	default_backend pg_leader
 
backend pg_leader
	mode tcp
	option httpchk
	http-check send meth GET uri /primary ver HTTP/1.1 hdr Host localhost
	http-check expect status 200
	default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
	server pg1 pg-knoten-01:5432 check port 8008 maxconn 100
	server pg2 pg-knoten-02:5432 check port 8008 maxconn 100
	server pg3 pg-knoten-03:5432 check port 8008 maxconn 100

# ============================
# LESEZUGRIFFE (alle, lastverteilung)
# ============================
# [~]# curl -s "http://admin:admin@localhost:8404/stats;csv" | grep -E 'pg_leader|pg_replicas' | awk -F',' '{print $2, $18, $56}'
# pg1 UP -1
# pg2 DOWN -1
# pg3 DOWN -1
# BACKEND UP -1
# pg1 DOWN -1
# pg2 UP -1
# pg3 UP -1
# BACKEND UP -1
frontend postgres_read
	bind *:5443				# Port zum lesen
	#default_backend pg_replicas		# bei Ausfall von 2 Knoten, kein lesen mehr möglich
	#
	# Wenn mindestens eine Replica gesund ist → Replicas
	use_backend pg_replicas if { nbsrv(pg_replicas) gt 0 }
	#
	# Andernfalls automatisch zum Leader
	default_backend pg_leader
 
backend pg_replicas
	mode tcp
	option httpchk
	balance leastconn			# Verteilt nach geringster Last
	http-check send meth GET uri /replica ver HTTP/1.1 hdr Host localhost
	http-check expect status 200
	default-server inter 3s fall 3 rise 2
	server pg1 pg-knoten-01:5432 check port 8008 maxconn 100
	server pg2 pg-knoten-02:5432 check port 8008 maxconn 100
	server pg3 pg-knoten-03:5432 check port 8008 maxconn 100