Minimizing the impact of orphan requests in e-commerce services

Abstract

The most common problem of an overloaded electronic-commerce server is an increase in the response time perceived by customers, who may restart their requests hoping to get a faster response, or simply abort them, giving up on the store. Both behaviors generate "orphan" requests: although they were received by the server, they should not be answered because their requestors have already abandoned them. Orphan requests waste system resources, since the server becomes aware of their cancellation only when it tries to send a response and finds out that the connection was closed. In this paper we propose a new kernel service, the Connection Sentry, which keeps track of requests being performed and notify processes about an eventual cancellation. Once notified, a process can interrupt the execution of the request, saving system resources and bandwidth. We evaluated the gains by using our proposal in a virtual bookstore, where we observed that the Connection Sentry reduced service latency by up to 31% and increased the throughput by 27% in overloaded servers.