Caching in the Middle Tier

For enterprise-level caching capabilities Spectrum Spatial Map Tiling Service can be disabled and a third-party caching technology such as Squid can be used.

Configuring Squid as a Reverse Proxy

The Squid caching proxy can be configured to be a reverse proxy for the Map Tiling Service so that pre-generated and on-the-fly map tiles can be cached and re-used. This decreases the amount of load that the service is under and allows Squid’s robust caching capabilities to be used.

Information on how to configure Squid as a reverse proxy can be found at wiki.squid.org.

One thing of note is how Squid caches content from an origination server when security is enabled. By default, Squid will not cache content from an origination server if some form of HTTP security is enabled. By default, Spectrum has BASIC HTTP authentication enabled. This means Squid will not cache tiles that the Map Tiling service returns. Squid can be configured, however, to ignore HTTP security by using its ‘refresh_pattern’ configuration directive. Here is an example ‘refresh_pattern’ that configures Squid to ignore HTTP security for all requests:

refresh_pattern . 0 0% 0 ignore-auth

Apply the pattern that makes sense for you application/service. Another alternative, if possible, is to disable platform level security altogether. See the "Securing Your System" section in the Spectrum™ Technology Platform Administration Guide. for more information.