# HAProxy backend postgres\_back has no server available

**URL:** <https://discourse.haproxy.org/t/haproxy-backend-postgres-back-has-no-server-available/11277>\
**Category:** Help!\
**Created:** [October 15, 2024, 3:31pm UTC](https://discourse.haproxy.org/t/haproxy-backend-postgres-back-has-no-server-available/11277 "2024-10-15T15:31:54Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bbandi](https://avatars.discourse-cdn.com/v4/letter/b/e95f7d/32.png) [@bbandi](https://discourse.haproxy.org/u/bbandi)\
**Post date:** [October 15, 2024, 3:31pm UTC](https://discourse.haproxy.org/t/haproxy-backend-postgres-back-has-no-server-available/11277/1 "2024-10-15T15:31:54Z")

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Hi Everyone,

For context : We’re trying to integrate PostgreSQL with Patroni & HAProxy along with zookeeper & keepalived.

HAProxy version 2.6.0-a1efc04 2022/05/31  
psql (PostgreSQL) 16.4  
patroni 4.0.2

PostgreSQL, HAProxy, Patroni, Keepalived, zookeeper installed on two servers (10.0.0.1, 10.0.0.2) and zookeeper is installed on one additional server (10.0.0.3) to maintain quorum.

Below are the configuration files of patroni and haproxy along with other information

patronictl -c /etc/patroni.yml list

- Cluster: postgres (7424658285489500758) -----±—±----------+  
| Member | Host | Role | State | TL | Lag in MB |  
±-------±--------------±--------±----------±—±----------+  
| node1 | 10.0.0.1| Leader | running | 12 | |  
| node2 | 10.0.0.2 | Replica | streaming | 12 | 0 |  
±-------±--------------±--------±----------±—±----------+

Curl works on both patroni nodes on 8008 port.

curl [http://10.0.0.1:8008/patroni](http://10.0.0.1:8008/patroni)  
{“state”: “running”, “postmaster\_start\_time”: “2024-10-15 06:59:13.591938-07:00”, “role”: “replica”, “server\_version”: 160004, “xlog”: {“received\_location”: 184549376, “replayed\_location”: 184550096, “replayed\_timestamp”: null, “paused”: false}, “timeline”: 12, “replication\_state”: “streaming”, “dcs\_last\_seen”: 1729005724, “database\_system\_identifier”: “7424658285489500758”, “patroni”: {“version”: “4.0.2”, “scope”: “postgres”, “name”: “node2”}}

haproxy.cfg file

global  
log /dev/log local0  
log /dev/log local1 notice  
maxconn 2000  
user haproxy  
group haproxy  
daemon

defaults  
log global  
option tcplog  
timeout connect 5000ms  
timeout client 50000ms  
timeout server 50000ms

frontend postgres\_front  
bind \*:5433  
default\_backend postgres\_back

backend postgres\_back  
option httpchk  
http-check send meth GET uri /patroni  
http-check expect status 200

```
server-template pg 2 10.0.0.15432 check inter 2000 rise 2 fall 3
server node1 10.0.0.1:5432 check
server node2 10.0.0.2:5432 check

option http-server-close
option httpchk GET /patroni

```

patroni.yml file from one postgresql server, a bit different on the second node.

scope: postgres  
namespace: /db/  
name: node1 # Unique name for the primary node

restapi:  
listen: 10.0.0.1:8008 # Node IP address  
connect\_address: 10.0.0.1:8008

zookeeper:  
hosts: 10.0.0.1:2181,10.0.0.2:2181,10.0.0.3:2181 # Zookeeper nodes

bootstrap:  
dcs:  
ttl: 30  
loop\_wait: 10  
maximum\_lag\_on\_failover: 1048576  
postgresql:  
use\_pg\_rewind: true

postgresql:  
user: postgres  
listen: ‘\*’ # Listen on all interfaces  
connect\_address: 10.0.0.1:5432 # Primary server IP  
data\_dir: /casdb/postgres/data/ # Data directory  
bin\_dir: /usr/pgsql-16/bin # PostgreSQL binary directory  
authentication:  
replication:  
username: repuser  
password: xxxxxxx  
superuser:  
username: postgres  
password: xxxxxxxx  
parameters: # PostgreSQL parameters can be configured here  
max\_connections: 100  
shared\_buffers: 256MB  
effective\_cache\_size: 768MB  
maintenance\_work\_mem: 64MB  
wal\_level: replica  
archive\_mode: on  
archive\_command: ‘test ! -f /casdb/postgres/walarch/%f && cp %p /casdb/postgres/walarch/%f’ # Updated archive command  
synchronous\_commit: on  
hot\_standby: on  
primary\_conninfo: ‘’ # Not needed for primary  
restore\_command: ‘’ # Not needed for primary

So far zookeeper, postgresql, patroni running fine and when I start the HAProxy service seeing the below error.

[root@testserver1~]# haproxy -f /etc/haproxy/haproxy.cfg -d  
Available polling systems :  
epoll : pref=300, test result OK  
poll : pref=200, test result OK  
select : pref=150, test result FAILED  
Total: 3 (2 usable), will use epoll.

Available filters :  
[CACHE] cache  
[COMP] compression  
[FCGI] fcgi-app  
[SPOE] spoe  
[TRACE] trace  
Using epoll() as the polling mechanism.  
[WARNING] (136627) : Server postgres\_back/pg1 is DOWN, reason: Layer7 invalid response, check duration: 2ms. 3 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.  
[WARNING] (136627) : Server postgres\_back/pg2 is DOWN, reason: Layer7 invalid response, check duration: 2ms. 2 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.  
[WARNING] (136627) : Server postgres\_back/node1 is DOWN, reason: Layer7 invalid response, check duration: 2ms. 1 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.  
[WARNING] (136627) : Server postgres\_back/node2 is DOWN, reason: Layer7 invalid response, check duration: 4ms. 0 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.  
[ALERT] (136627) : backend ‘postgres\_back’ has no server available!

Broadcast message from systemd-journald@testserver1(Tue 2024-10-15 07:28:34 PDT):

haproxy[136627]: backend postgres\_back has no server available!

Broadcast message from systemd-journald@testserver1 (Tue 2024-10-15 07:28:34 PDT):

haproxy[136627]: backend postgres\_back has no server available!

Message from syslogd@testserver1 Oct 15 07:28:34 …  
haproxy[136627]:backend postgres\_back has no server available!

Message from syslogd@testserver1 at Oct 15 07:28:34 …  
haproxy[136627]:backend postgres\_back has no server available!

Could someone share thoughts in case if I’m missing any thing here.

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**Author:** ![rradutiu](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@rradutiu](https://discourse.haproxy.org/u/rradutiu)\
**Post date:** [October 21, 2024, 12:31pm UTC](https://discourse.haproxy.org/t/haproxy-backend-postgres-back-has-no-server-available/11277/2 "2024-10-21T12:31:02Z")

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Your server lines are missing the port for the check. You are using option httpchk but with a missing “check port 8008” on those lines, the check will be sent to postgres, not to patroni.