Admin: HTTP Proxy Cache

Revision as of 18:32, 5 October 2010

When you want to increase performance, one of the easiest and most effective techniques is to use Resin's proxy cache and improve the ratio of pages using that cache. A page request that avoids any database access or framework processing is a pure win for performance and latency. The proxy cache can be particularly effective in combination with load balancing because Resin's proxy cache can save load on the web-tier server itself.

Summary

You can use the summary page to get an overview of the cache effectiveness by looking at the miss ratio of the proxy cache and block cache. The lower the miss ratio, the fewer requests that take up database and framework load. Each "miss" is a request that goes through the full processing of a page.

proxy cache miss ratio

The percentage of requests that miss the caching, going on to full processing.

block cache miss ratio

The underlying disk reads and writes ("block reads/writes") paging from memory caching to disk caching.

invocation cache miss ratio

Counts the invocation misses, which is when Resin must calculate rewrite, servlet and filter dispatching for splitting apart the URL

Summary Example

In the example below, the miss ratio is 11.3%, meaning 11% of all cacheable requests to the server are missing the cache. 22,000 requests use the cache and 2,800 requests miss the cache.

Although the miss ratio is important, it's even more important to know which pages are missing the cache. A slow page like a database access that misses the cache is more important than a fast page like a static page that misses the cache. The following two tabs give more details of which pages are getting cached.