Implementing Protocols in Java: The Price of Portability

As the number and variety of Weband network-based applications continues to increase, so does the need for flexible communication protocols and services to support them. Traditionally, a major impediment to deployment of new protocols is the need to upgrade millions of end-systems with compatible implementations. At the same time, Java — a language explicitly designed to support development and distribution of new applications via the Web — is emerging as a (potentially) ubiquitous system platform. It is therefore natural to consider whether Java might speed the introduction of protocols to better support new applications. In this paper, we investigate the tradeoffs involved in using Java for protocol implementation and deployment. Using insights from a Java-based protocol suite and supporting subsystem we have implemented, we describe the benefits of using the Java language and quantify the performance cost of implementing a protocol in Java for various combinations of interpretation and compilation. We find that the performance cost of using Java-based protocols is presently equivalent to four years of hardware performance gains, i.e., interpreted, Java-based protocol performance on current hardware is roughly equivalent to the performance of compiled C code on four-year-old hardware. This work was supported in part by grants from the National Science Foundation (NCR-9612855, NCR-9628379, and NCR9305115). Java, JavaStation, JavaOS, JavaChip, and Solaris are all trademarks of Sun Microsystems, Inc.