This section provides a high-level overview of the quality of the end-user experience and the occurrence of any slowdowns. The chart breaks down the time required to complete a single transaction, such as an HTTP request.

The End-to-End pane displays the following components:

Name

Description

Server RTT

This is SE to server round trip latency. An abnormally high server RTT indicates either that the network is saturated or that a server’s TCP stack is overwhelmed and cannot establish new connections quickly.

App Response

The time the servers take to respond. This includes the time the server took to generate content, potentially fetch back end database queries or remote calls to other applications, and begin transferring the response back to Avi Load Balancer. This time is calculated by subtracting the server RTT from the time of the first byte of a response from the server. If the application consists of multiple tiers (such as web, applications, and database), then the App Response represents the combined time before the server in the pool began responding. This metric is only available for a Layer 7 virtual service.

Data Transfer

Represents the average time required for the server to transmit the requested file. This is calculated by measuring from the time the SE received the first byte of the server response until the client has received the last byte, which is measured as when the last byte was sent from the SE plus one half of a client round trip time. This number varies depending on the size of objects requested and the latency of the server network. The larger the file, the more TCP round trip times are required due to ACKs directly impacted by the client RTT and server RTT. This metric is only used for a Layer 7 virtual service.

Total Time

The time it takes for a client to receive a response after sending a request. It is the most critical end-to-end timing number to watch because it is the sum of the other four metrics. If it is consistently low, the application is successfully serving traffic.

For more information on the chart and overlays pane, see Chart Pane and Overlays Pane.