Restart Elastic Beanstalk App Server when Health is Severe

Question

Hello, I am running a spring boot application on Elastic Beanstalk using Tomcat 8.5 with Corretto 11 running on 64bit Amazon Linux 2/4.2.12. Every couple of days I am getting the error "Following services are not running: tomcat.", with Severe Health status and a down server. I am not seeing useful information in the catalina.2022-xx-xx.log files. Restarting the app server fixes the issue. 
Instance type is t2.micro. 
I would appreciate help in understanding

1) how to understand what is wrong with my setup.

2) recover and restart the server automatically so I won't have to manually do it every time until a fix has been found.
 
Thank you.

Answer

The tomcat / catalina.log logs should reveal the cause, you may need to up the logging level or add additionally logging. It is possible it is resource related and some of the [tomcat memory parameters](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/command-options-specific.html#command-options-java) need updating eg max heap size but you need to be sure this is the cause.

if you are using a load balancer you could add a load balancer health check and configure automatic termination within the autoscale group (I believe this is not a native config and will require ebextensions)

If not using a load balancer you could add a cloudwatch alarm on the environment health metric and then configure an alarm action to reboot the instance - see [here](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/UsingAlarmActions.html#AddingRecoverActions)

Restart Elastic Beanstalk App Server when Health is Severe

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