1. Introduction

ContainerManager acts as a scheduler to decide which invoker to create a container based on etcd data. It also deletes containers that have actions other than the current version.

Therefore, it knows the information of all invokers registered in etcd, and saves it in in-memory in the form of a map.

2. Architecture Diagram

ContainerManager is an Actor component and handles two main messages of container creation and deletion.

2-1. Creation

When the ContainerCreation message is received, ContainerManager determines the invoker to create the container. When It decide Invoker, It register for the CreationJobManager to wait for the creation of the container. At the same time, send a CreationMessage to Kafka to pass the container creation message to Invoker.

2-2. Deletion

It may receive a deletion message for deletion of containers generated by previous versions of the current version. When the ContainerManager receive this message, it query the Invoker that has an old version container in the ETCD and then sends a ContainerDeletion message to that Invoker through Kafka.