Baruwa is capable of running in a cluster.
Full Baruwa functionality is available from any member within a Baruwa cluster and all cluster members have equal status. This allows you to provide round robin access either using Load Balancers or DNS configuration. This makes the running of a cluster totally transparent to the end users.
Baruwa stores client session information in Memcached, so all the nodes in the cluster should be configured to use the same Memcached server.
All nodes should be configured to either use a clustered MQ broker or use the same MQ broker as the other nodes. The nodes should be aware of the other nodes queues to enable them to submit tasks to those queues.
All the nodes with in a cluster should be configured to write to a single database and index data to a single or distributed sphinx server.
The full requirements are:
- Shared Memcached server
- Shared PostgreSQL server
- Shared MQ broker or clustered broker
- Shared Sphinx server or distributed sphinx servers
The recommended setup is to have Memcached, PostgreSQL, RabbitMQ, Sphinx running on a separate server. This called the Distributed Backend Distributed Frontend topology.
If installed using the correct System Profiles the correct ports will be open on the host firewall. You may however wish to make the firewall more restrictive by allowing only your cluster machines to connect to the ports.
The firewall on the server hosting the above shared services needs to be configured to allow the following connections from the cluster nodes.
- TCP 9312, 9306 - Sphinx
- TCP 5432 - PostgreSQL or 6432 Pgbouncer
- TCP 4369 - RabbitMQ EPMD
- TCP 11211 - Memcached
This limitation is not present when using a shared quarantine.
Quarantines are node specific, so messages quarantined on a failed node will not be accessible until the node is restored.
Baruwa Enterprise Edition can be setup to use load balancers that support the Proxy-protocol, the most popular being Haproxy.
To use Baruwa Enterprise Edition SMTP servers with these load balancers you
need to specify the load balancer IP addresses in the
Load Balancer IP’s
field on the
MTA Settings screen in
A sample configuration for haproxy with both HTTP and SMTP being load balanced is below.
global log 127.0.0.1 local0 log 127.0.0.1 local1 notice maxconn 4096 chroot /var/lib/haproxy user haproxy group haproxy daemon defaults log global mode http option httplog option dontlognull option redispatch retries 3 maxconn 2000 timeout connect 5000 timeout client 50000 timeout server 50000 listen http :80 mode tcp option tcplog balance roundrobin server web1 192.168.1.20:80 check server web2 192.168.1.23:80 check listen https :443 mode tcp option tcplog balance roundrobin server web1 192.168.1.20:443 check server web2 192.168.1.23:443 check listen smtp :25 mode tcp no option http-server-close option tcplog timeout server 1m timeout connect 5s balance roundrobin server smtp1 192.168.1.22:25 send-proxy server smtp2 192.168.1.24:25 send-proxy