Squid accelerator tips to serving content when a backend server is down

We can have squid to serve stale objects although the backend server is down.

• Make sure negative_ttl is set to 0 seconds to disable the caching of errors.
• If the web server become unreachable, set the connect timeout sufficiently short. There are three different connect timeouts depending on your config and requirements:

- config_timeout: for requests going DIRECT
- peer_config_timeout: for requests going to a cache_peer
- cache_peer ... timeout=XXX: specific timeout for this cache_peer, this one override peer_config timeout.

Default values are 1 minute for requests going direct and 30 seconds for requests sent to a cache_peer.

As a general statement in accelerator setups, you want the backend connect timeout quite short, a few seconds.