Troubleshooting Slow Data Delivery

Applies To:

HTTP LargeThis platform has been optimized to cache and deliver static content (e.g., HTML, CSS, JavaScript, ISO, multimedia, and software downloads, etc.) over HTTP or HTTPS.

HTTP SmallLegacy. If you are currently serving traffic over this platform, then you may continue to do so. However, we recommend that you serve your traffic over our more robust HTTP Large platform.

ADNThe Application Delivery Network platform has been optimized to deliver dynamic content (e.g., login credentials, account information, etc.) over HTTP or HTTPS. Typically, user-specific and database-driven content are served over this platform.

Purpose

The purpose of this procedure is to diagnose sub-optimal HTTP data delivery performance.

It is highly recommended that this troubleshooting procedure be performed from the computer where the performance issue was detected.

CDN Delivery Details

Find out the platform and the POP location through which a request is being served.

Checklist:

Request slow performing content using a tool that provides response header data.

Verify that the response contains a header called "Server." Our Technical Support personnel use this information to find out the POP location and the server that fulfilled the request.

Missing Server Response Header: Verify that the request points to the CDN.

Edge CNAME URL: Check DNS by performing a dig on the hostname.

Use your DNS service provider to update the CNAME record to point to the proper CDN hostname.

Network Issues

Use the traceroute tool to check for network issues between the computer experiencing performance issues and the edge of our network.

Checklist:

Perform a traceroute to the hostname specified in the request URI.

Speed Test

An ISP can cause sub-optimal performance for its customers regardless of whether the content is served through our CDN.

Checklist:

Perform an Internet speed test to determine whether a user's ISP is affecting performance.

Performance Waterfall

A waterfall provides a visual representation of a site's performance that may be used to reveal performance bottlenecks.

Checklist:

Generate a waterfall and check for bottlenecks.