Why we need to restart LightSail after interval of some days

Thanks for using Lightsail! I found a thread related to swap space. Hopefully this can solve your issue. If you need further help, please contact Customer Support and cut Lightsail a ticket and our engineer will help investigate the root cause.

Hello,

Thank you for reaching out. You might be facing the issue of your WordPress site going down after a few days due to the host running out of system resources such as memory (RAM). This would cause the site to become unresponsive or go down forcing you to reboot your Amazon LightSail instance.

One way to avoid this situation in future can be to monitor your memory usage using Amazon CloudWatch. You can configure your LightSail instance to work with Amazon CloudWatch to receive specific metrics including memory usage using a CloudWatch agent.

If the growth of your project requires more memory you can also use features such snapshots in Amazon LightSail to create a larger instance more suited to your memory requirements.

You can also upgrade to Amazon EC2, which would allow you to choose a specific type of instance that is more suited and optimized for your workload. This would also give you the many benefits of Amazon EC2 such as elasticity, auto scaling and access to software that is not offered on Amazon LightSail.

https://aws.amazon.com/blogs/compute/monitoring-memory-usage-lightsail-instance/

https://lightsail.aws.amazon.com/ls/docs/en_us/articles/how-to-create-larger-instance-from-snapshot-using-console

https://aws.amazon.com/lightsail/features/upgrade-to-ec2/?fpdp4=upgrade