Comparing Apache Tomcat threading to AWS Lambdas we see several points:
- Apache handles concurrent requests internally with a multi-threaded Java Virtual Machine (JVM). The JVM used by AWS Lambas does NOT allow multi-threading. Concurrent requests are handled by multiple Lambda instances
- Scaling with Apache Tomcat is achieved with multi-threading and load-balancing additional servers. AWS Lambdas scales by provisioning additional instances as needed.
Anecdotes 