Determining Web Service Dependencies From Limited TCP Packets
Dhaval Shah, Manoj Karunakaran Nambiar · 2019
In web applications with tier-wise architecture, a server in tier n takes services from a server in tier n + 1. In such a services based architecture it is essential to know what services are used from a server in the (n +1)th tier by a service in nth tier. i.e. service dependencies. This helps in debugging end user response time issues, to improve the quality of online experience. It is required to understand the exact nature of dependencies amongst the tiers. For example, in the case of web applications, it is essential to know which SQL queries are executed by a given http request in a web/application server. Often, this information is not available to the operational staff maintaining production systems. Commercial tools with high licensing costs work by instrumenting the code, aid in analysis, but their impact on performance cannot be ignored. This paper outlines a simple and light weight algorithm to learn service dependencies from the data obtained in the form of network packet traces.