SummaryIf a webpage is sent to edge cache to be cached, but the connection to the page is closed before edge cache can get any data, the above error will occur.
OverviewIn order to cache page, the Exinda's edge cache needs to initiate its own connection to the server to download the page directly to the cache, so it can later be served up to end users. Occasionally, when browsing to a web page, users will get a 'zero sized reply' error instead of the webpage expected.
CauseThe back end of edge cache, an engine called squid, will return this error if the connection between itself and the web server presenting the page is terminated before any data is transmitted. Furthermore, it means that the connection was attempted at least once again and reached the same condition. This can be for a number of reasons, such as:
- Server overload (whether through standard use or through an ongoing Denial of Service attack)
- Extremely large third party cookies
- Strange behaviour in the TCP connection
Resolution?These are typically random in nature and can be resolved by waiting a period of time and attempting again.
Alternatively, the sites in question can be added temporarily to the 'do not cache' list on the Configuration > System > Optimization, "Edge Cache" page. This will ensure that the page is not cached and thus, stop the error from occurring.