Improving Performance

PopChart Server User Guide 4.0.5

Caching

Available only in PopChart Server Enterprise.

You can enable caching in the Settings > Cache / Connections section of the Administration Console. Simply enter the desired cache size (in images) in the Cache Size box.

When caching is enabled, PopChart Server stores the server request string and the generated image in a cache. When the same request is received, PopChart Server sends back the previously generated image. This is very fast as it doesn't require disk access or regeneration of the image.

Even if there is a possibility of thousands of different variations on a certain graph, it is useful to have a cache size of around 100 to 1000 images if there is a likelihood that certain graphs will be viewed more frequently than others.

If you load data from a file with either the PopChart Embedder or PCScript while caching is enabled, PopChart Embedder will check the timestamp of the file that it loads. If the timestamp hasn't changed, the cached image will be used. Otherwise, a new image with the updated data will be generated.

The cache size can be as large as you desire. However, keep in mind that the cache uses RAM and not disk space. Cache sizes of 100 to 1000 images are typical.

When the cache reaches its maximum capacity, the oldest image will be bumped out.

If the data being graphed is never, or rarely the same, using the cache is not recommended. You can disable the cache by setting Cache Size to 0. You can also specify that a certain image is not to be cached by using either the useCache PopChart Embedder attribute, or the @_DONTCACHE server command (this also instructs the browser not to cache the image).

Appearance File Caching

Available only in PopChart Server Enterprise.

A new feature in PopChart Server 4.0.5 is appearance file caching. When this is enabled, PopChart Server will store the most recently accessed appearance files in RAM. If you use the same appearance files often, this will help cut down on disk-access times. However, it requires more RAM.

To enable the appearance file cache, check the Enable Appearance File Caching box on the Settings > Cache / Connections page in the Administration Console.

Note: Use this setting carefully. After PopChart Server caches an appearance file, it will never load it again, even if there is a newer version available. For more information, refer to "I Updated an Appearance File or Image but it Looks Like PopChart Server Used my Old File".