Generally, the term latency describes any timed delay (typically in milliseconds) between the start and completion of a process. It measures how quickly or slowly data travels between points in a system. In a networking sense, a few types of latency interest us the most: 

  • Transmission latency – The time it takes for data to physically move between a source and destination. Transmission mediums like cables can impact latency, as can hardware processing times.

  • Network latency – The time it takes for data to travel from the source to the destination over a network. It includes transmission latency, processing latency at devices like routers, and queuing latency.

  • Round-trip latency – The time it takes for a signal or packet to travel from the source to the destination and back. Round-trip latency is important to measure when a response or acknowledgment is required.

Why does latency matter?

When it comes to networking, the faster data travels, the better. And when a user performs an action, any perceived delays in execution (e.g. retrieving the data you want) can negatively impact user experiences. This manifests itself in many ways. For example, a web page might take a long time to load for users without a regional server. Alternatively, network congestion might prevent your process (perhaps a web request or API call) from immediately starting. It's similar to placing an order fifth and waiting for staff to fulfill the four orders before yours. 

There's a UX argument to be made, and there's application acceleration to consider. By optimizing how data traverses the network or how processes finish up, it's possible to extract the very best performance from your backend infrastructure. 

How does HAProxy address latency?

We have multiple application acceleration measures in place to reduce latency across HAProxy Enterprise, HAProxy ALOHA, and HAProxy Enterprise Kubernetes Ingress Controller—mainly at the application layer. HAProxy leverages response caching, connection pooling, advanced HTTP compression, content buffering, and more to optimize how network data travels. 

Meanwhile, our HAProxy Edge application delivery network (ADN) packages together our CDN with features like SmartRouting to boost data transmission efficiency.