Apache Reference: mod_proxy, CacheForceCompletion

CacheForceCompletion

Completion Watermark for Cancelled HTTP Transfers
Syntax: CacheForceCompletion A
Example: CacheForceCompletion 60
Since: Apache 1.3

If an HTTP transfer that is being cached is cancelled, mod_proxy will complete the transfer to the cache if more than the percentage of the data has already been transferred. This percentage must be a number between 1 and 100 (0 is the default). A value of 100 will cause a document to be cached only if the transfer was allowed to complete. Use of a number between 60 and 90 is recommended.