The Design And Implementation Of Warden Framework In Cloud Foundry

This article mainly discusses one platform-as-a-service product called cloud foundry. And in detailed, it will tell us about the warden framework which was used in cloud foundry. The VMware Inc provided the world with his open sourced application solution. With this product, developers can deploy their applications onto the cloud foundry platform out of the concern of deployments. For cloud foundry, there are so many exsting compoments. Without the limitation on system resource, one crash in a simply application can result into the shutdown of the whole platform. For this reason, warden was deploped to isolate resources, puting some limitations on resource control. It mainly used the linux control group and namespace to fulfill its requirements, enhance the load for sub-moduler.Starting with the background of the cloud foundry project, it shows the requirement of warden framework and the basic information of warden framework. Then it turns into the use scenarios of the warden framework and the detailed introduction for the advantages of this product. After that, it mainly discusses the technical backgroup including the used technologies and the involved concepts. For techonology, it discussed the event machine, ruby on rails, container based virtualization and control group technology. When came to concepts, it made an introduction about PaaS, laaS and Saas. Next chapter, it covers the requirement analysis, design for the whole system and the artichtecture of the deployment. Then it goes into a detailed discuss about warden client module, warden server module, warden protocol module and em warden client module. Finally, it talks about the function points like iomux, repquota, wsh and oom.The warden client module is a tiny client and it provides the basic operations to communicate with the warden server. The em warden client is one enhancement with event machine for the warden client. In this way, this client was programmed into a networked paralled approach. Warden protocol is mainly some protobuf files, communicated on the socket. Both the warden client and the warden server can understand it. The warden server is the main module, which implement the manipulation of the container and the dispatchment of the threads. This module can manage the states of container and control and isolate cpu, memory, width and IO and some other system resource.