Learn how to set up PostgreSQL with HAProxy and Keepalived. Our PostgreSQL Support team is here to help you with your questions and concerns.

Keepalived HAProxy PostgreSQL | Configuration

Did you know that setting up PostgreSQL load balancing with HAProxy and Keepalived helps us create a robust and highly available database infrastructure?

It makes sure that our database service is accessible and responsive during hardware failures or maintenance events as well.

Furthermore, this setup optimizes resource utilization by distributing database connections evenly across multiple nodes.

Benefits of this configuration

• High Availability:

  Keepalived makes sure that VIP is accessible, and HAProxy directs traffic to active database nodes. In case a PostgreSQL node or HAProxy instance fails, Keepalived automatically handles failover.
• Load Balancing:

  HAProxy balances database connection requests by distributing the workload across all database nodes.
• Fault Tolerance:

  The replication and clustering features offered by PostgreSQL prevent data loss and ensure data consistency.

How to set it up

Before we begin, here are a few prerequisites:

• We need multiple PostgreSQL database nodes with data replication or clustering in place.
• We have to install PostgreSQL on all the nodes and configure them to work as part of a replication cluster.
• Next, set up multiple servers for the HAProxy and Keepalived components. These servers will be different from the PostgreSQL nodes.
• Make sure that the servers are running a compatible Linux distribution.

Once the above points have been taken care of, we can start the setup process:

1. First, we have to set up our PostgreSQL database cluster with replication and clustering. This involves configuring streaming replication, logical replication, etc as per our needs.
2. Now, we have to install HAProxy on a dedicated server that will act as the load balancer for database connections.
3. Then, we have to configure HAProxy to distribute incoming database connection requests to the PostgreSQL nodes. This involves defining backend servers by specifying the IP addresses and ports of our PostgreSQL nodes.

   Additionally, we have to create a frontend configuration to listen on a specific port and direct incoming traffic to the backend servers.
4. Now we have to install Keepalived on two separate servers that are not part of our PostgreSQL or HAProxy clusters.
5. Next, configure Keepalived to manage the VIP. This should include health checks for PostgreSQL and HAProxy instances.
6. Then, define the VIP address.
7. After that, specify the servers that will participate in the Keepalived setup.
8. Additionally, set up health checks to monitor PostgreSQL and HAProxy services.
9. We also have to set up the failover behavior.
10. Now, it is time to test the setup by connecting to the VIP using a PostgreSQL client. We can simulate failures by stopping PostgreSQL on an active node, killing the HAProxy process, or shutting down one of the Keepalived servers to ensure that failover occurs as expected.

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Conclusion

In brief, our Support Experts demonstrated how to set up PostgreSQL load balancing with HAProxy and Keepalived.