(v22) Configure a High Availability Environment

Configure a High Availability Environment

A high availability environment is designed to ensure concurrent users having access to the same microservices at the same time, including the COMPOSER-WEB service. To have a high availability environment, you need to Configure a High Load Environment along with setting up at least two instances of each microservice, including COMPOSER-WEB. These services must be accessible through a Load Balancer.

Note how this is different from how you would Configure a High Load Environment, because you are adding multiple instances of each microservice.

Setting Up Your Load Balancer

The following steps provide an example of setting up HAProxy as a load balancer. Regardless of what kind of load balancer you use, ensure that port 443 is open on it.

To set up an HAProxy load balancer:

1. On your machine, run the following command to install HAProxy:

   sudo yum install haproxy

2. Navigate to the HAProxy folder.

   cd /etc/haproxy

3. Create a certificate or copy an existing certificate to the /etc/haproxy folder. If you need to create a certificate, run the following commands:

   sudo openssl genrsa -out ca.key 1024
   sudo openssl req -new -key ca.key -out ca.csr
   sudo openssl x509 -req -days 365 -in ca.csr -signkey ca.key -out ca.crt
   sudo vi cert.pem #Create and save an empty file
   sudo chmod a+w cert.pem
   sudo cat ca.key ca.crt > cert.pem

4. In the same folder, replace the contents of the haproxy.cfg file with the contents of the Composer haproxy configuration file. In the file, replace the <node1-ip> and <node2-ip> with the IP addresses of your servers. If you have more than two servers, add additional lines for each server.

5. Save your changes and exit the file.

6. Start the HAProxy microservice

   sudo service haproxy restart

7. Use the following command to configure the HAProxy microservice to start automatically in CentOS 7 environments:

   sudo systemctl enable haproxy
                   

8. Ensure that port 443 is open on your load balancer. If not, run the following command:

   sudo iptables -I INPUT 1 -p tcp --dport 443 -j ACCEPT
   sudo service iptables save

For assistance with configuring SAML for use with HAProxy, contact Composer Technical Support.