OnApp Accelerator: technical information


OnApp Accelerator is included in the OnApp Cloud platform v6.0 and higher. It’s available at no additional cost to OnApp cloud service providers, subject to a fair usage policy.

When Accelerator is active for a Virtual Server running in an OnApp cloud, its web content is automatically optimized, compressed and distributed to locations around the world – so end users can download it from the location nearest to them.

There are three main components to OnApp Accelerator: a hypervisor in an OnApp cloud; an Accelerator Virtual Server appliance, that sits between the hypervisor and the virtual server being accelerated; and a global Content Delivery Network, which is provided and managed by OnApp.

OnApp Accelerator is included in the OnApp Cloud platform v6.0 and higher.

The Accelerator appliance

The Accelerator is a Virtual Server appliance that sits between the hypervisor and the Virtual Server hosting the web application.

  • When a Virtual Server is accelerated, traffic is rerouted through the Accelerator
  • The Accelerator handles the HTTP/HTTPS request from the end user’s browser, and proxies it to the Virtual Server
  • It automatically provides SSL certificate for HTTPS traffic with Lets Encrypt
  • The response is optimized by being minified, compressed and CDNified
  • This is performed with nginx and pagespeed
  • File types optimized by OnApp Accelerator:
    • HTML
    • CSS
    • GIF
    • JS
    • JPG
    • PNG
    • WEBP

The Accelerator is also the origin for the CDN edge servers, which pull the optimized content from the Accelerator for caching.

Hypervisor & rerouting

When a virtual server is accelerated, ebtables and iptables firewall rules are applied on the hypervisor host to reroute HTTP/HTTPS traffic through the accelerator.

The whole Virtual Server is accelerated, regardless of how many websites it’s hosting.

OnApp Accelerator has a built-in monitoring and failover mechanism.

OnApp Accelerator has a built-in monitoring and failover mechanism. Should the Accelerator VS appliance malfunction, the ebtables and iptables rules are removed, and HTTP/HTTPS requests are immediately routed back to the target VM.

Content Delivery Network

OnApp Accelerator distributes content to 20 locations on a global Content Delivery Network managed by OnApp. We’ve chosen CDN locations (PoPs) to provide broad global coverage:

Americas Europe Asia Australia
Dallas Amsterdam Hong Kong Melbourne
Montreal Frankfurt Jakarta Sydney
Queretaro Karlskrona Singapore
San Jose London Tokyo
Sao Paulo Milan
Seattle Paris

Accelerator automatically rewrites the URLs of static content to the CDN. For example:

Original URL – http://example.com/a.jpg
CDN URL – http://invicdn.worldcdn.net/123/


The table below shows the results of benchmarks for a virtual server running a typical e-commerce website, with and without Accelerator enabled:

  Original Accelerated
File size 1.14MB 0.47MB
Load time 3.9s 1.9s
File requests 52 13


OnApp Accelerator decreased the entire file size close to 60%, reduced load time by more than 50%, and resulted in 75% fewer file requests to the accelerated virtual server, compared to the original.

A simple way to benchmark ‘before and after’ performance is to measure the performance of a website running on an accelerated virtual server, and then measure the same website with “?PageSpeed=off” appended to the URL being tested. This will ignore the Accelerator function while you test. E.g. http://www.example.com/?PageSpeed=off