Configuring haproxy v23
TPA will install and configure haproxy on instances whose role
contains haproxy
.
By default, haproxy listens on 127.0.0.1:5432
for requests forwarded
by pgbouncer
running on the same instance. You must
specify a list of haproxy_backend_servers
to forward requests to.
TPA will install the latest available version of haproxy by default.
You can install a specific version instead by setting
haproxy_package_version: 1.9.15*
(for example).
Note: see limitations of using wildcards in package_version in tpaexec-configure.
Haproxy packages are selected according to the type of architecture. An EDB managed haproxy package may be used but requires a subscription. Packages from PGDG extras repo can be installed if required.
You can set the following variables on any haproxy
instance.
Variable | Default value | Description |
---|---|---|
haproxy_bind_address | 127.0.0.1* | The address to which haproxy should bind *0.0.0.0 if failover_manager is patroni. Users should change this value to something more restrictive and appropriate for their cluster networking |
haproxy_port | 5432 (5444 for EPAS) | The TCP port haproxy should listen on |
haproxy_read_only_port | 5433 (5445 for EPAS) | TCP port for read-only load-balancer |
haproxy_backend_servers | None | A list of Postgres instance names |
haproxy_maxconn | max_connections ×0.9 | The maximum number of connections allowed per backend server; the default is derived from the backend's max_connections setting |
haproxy_peer_enabled | True* | Add known haproxy hosts as peer list. * False if failover_manager is harp or patroni. |
Read-Only load-balancer
Haproxy can be configured to listen on an additional port for read-only access to the database. At the moment this is only supported with the Patroni failover manager. The backend health check determines which postgres instances are currently acting as replicas and will send traffic using a roundrobin load balancing algorithm.
The read-only load balancer is disabled by default but can be turned on
using the cluster_vars variable
haproxy_read_only_load_balancer_enabled
.
Server options
TPA will generate /etc/haproxy/haproxy.cfg
with a backend that has
a default-server
line and one line per backend server. All but the
first one will be marked as "backup" servers.
Set haproxy_default_server_extra_options
to a list of options on the
haproxy instance to add options to the default-server
line; and set
haproxy_server_options
to a list of options on the backend server to
add options (which will override the defaults) to the individual server
lines for each backend.
Example
- On this page
- Read-Only load-balancer
- Server options
- Example