Cs-Tries

Fast Topic Matching

A common problem in messaging middleware is that of efficiently matching message topics with interested subscribers. For example, assume we have a set of subscribers, numbered 1 to 3: Subscriber Match Request 1 forex.usd 2 forex.* 3 stock.nasdaq.msft And we have a stream of messages, numbered 1 to N: Message Topic 1 forex.gbp 2 stock.nyse.ibm 3 stock.nyse.ge 4 forex.eur 5 forex.usd … … N stock.nasdaq.msft We are then tasked with routing messages whose topics match the respective subscriber requests, where a “*” wildcard matches any word. This is frequently a bottleneck for message-oriented middleware like ZeroMQ, RabbitMQ, ActiveMQ, TIBCO EMS, et al. Because of this, there are a number of well-known solutions to the problem. In this post, I’ll describe some of these solutions, as well as a novel one, and attempt to quantify them through benchmarking. As usual, the code is available on GitHub.