Zendesk, Inc.
Using an inverse cumulative histogram to efficiently analyze web service request latencies

Abstract:

The disclosed embodiments relate to a system that analyzes latencies for web service requests. During operation, the system receives web service requests at a web service. The system also records latency values associated with processing the web service requests in an inverse cumulative histogram, which is stored in a set of bins, wherein each bin is associated with a range of latency values between a high range value and a low range value, and wherein each bin contains a sample count for latencies that fall within the bin plus a sample count of an adjacent bin associated with a next higher range of latency values. Next, upon receiving a request to determine a number of web-service requests having latencies that are less than a target latency value, the system returns a sample count from a matching bin, which has a high range value that matches the target latency value.