Struggling with Load Balancer Configuration for High Traffic Websites

Hi there,

As this is only happening during peak traffic times, there are a few things that I could suggest here:

On the backend Droplets side:

• Make sure that your backend services have enough resources to handle the incoming traffic. You can either use the DigitalOcean monitoring graphs to take a quick overview of your resource utilization and also follow the steps here on how to find which processes are consuming most of the resources on your server by following the steps here:

https://www.digitalocean.com/community/questions/how-to-find-the-processes-that-are-consuming-the-most-server-resources

• Once you are able to pinpoint the services consuming most of the resources you could either plan for an upgrade or try to optimize those services, but this would depend on the above findings.

On the database side:

• Again make sure that the database cluster has enough resources to handle all of those 50,000 requests per minute. You might want to consider scaling up if there aren’t enough resources.
• Go through your query log and see if there are any particular queries that are slow here. You can follow the the steps on how to do that here:

https://docs.digitalocean.com/products/databases/mysql/how-to/monitor-databases/

• Sometimes adding a few indexes can drastically improve the performance of such slow queries.

• If you have a lot of read operations, you could plan on scaling horizontally by adding some read replicas and configuring your app to use the read replicas for all or some of your read queries, that way you will reduce the load on the primary server which will only handle the writes. Depending on the framework that you are using this might be easily configurable, for example, Laravel offers this out of the box.

On the sessions side:

• Rather than solely relying on the sticky sessions, you could introduce a centralized sessions store for all of your Droplets. Consider using an external session store a managed Redis instance to manage sessions centrally. This can help avoid session loss when users are redirected to different Droplets.

On the load balancer side:

• To reduce the overall latency and load on the load balancer itself, what you could do here is to use a CDN service like Cloudflare. This will not only be beneficial if your website serves a lot of static content, but will in general reduce latency for users by serving content from edge locations.

Hope that this helps!

- Bobby