Performance improvement of clustered internet server systems based on the collaboration of linux I/O subsystems and enhancement of OpenLDAP implementation

Abstract

The explosion of the Internet and World-Wide-Web technologies has led to the development of many new systems and the severe overload of a current Internet infrastructure. It has also created a critical need for many new Internet server technologies such as server clustering, content delivery networks, and smart proxies. The server clustering technologies have been in the core of the efforts to realize the high-performance Internet platform so as to make it capable of providing the full power of ubiquitous Internet services. In the platform, two types of services infrastructures need to be prepared for a complete support for real Internet service deployment: Internet content service infrastructure and credential information service infrastructure. In the content service infrastructure which mainly targets on HTTP, FTP, and streaming services, the key operation is to deliver contents to clients. It needs to be designed with deep consideration in scalability, high-throughput, and reliability. On the other hand, the credential information service infrastructure which provides standardized access methods to credential information such as user accounts, passwords, certificates, etc, requires a high interoperability and a security level which leads to active research on directory services as a credential information repository. In order to build a complete service infrastructure, both service infrastructures need to be co-located and interoperate with each other. In this thesis, both infrastructures have been improved by a series of techniques on top of a PC-cluster based Internet server. For the Internet content service infrastructure, in order to improve throughput of a Internet server by eliminating avoidable context switching between data copying operations which severely damage cache efficiency, we proposed an event-correlation based event manager (ECEM) in a Linux operating system. In Internet servers that run on general-purpose ...