v1.17

• Background revalidation jobs can now pass headers from the originating parent request. These are configurable, with the defaults being Authorization and Cookie, and can also be modified be binding to the set_revalidation_headers event.
• Add event to modify parent headers passed into background revalidate
• PURGE jobs now heartbeat between SCANs
• Explicitly flush yielded data before each esi:include

v1.16

• Moved wildcard purges to a background job, managed by Qless. This means that wildcard purges will always return 200, regardless of whether there was anything to purge or not.
• Wildcard purges now attempt to use a Redis slave for SCAN commands, if available.
• Qless jobs are now tagged with their type, as purge, revalidate or collect_entity. This helps tracking.
• Qless jobs now have different priorities: collect_entity is highest, revalidate second, and purge lowest.
• max_stale config setting now ignores response headers in deciding if it's ok to serve stale (essentially it overrides). Though they are still honoured when the client issues a Cache-Control: max-stale=n header.
• Background revalidation now has SSL support.

v1.15

• Bugfix: Whitespace in esi:include tags wasn't handled. Thanks @hamishforbes.

v1.14

• Added locking for concurrent identical wildcard PURGE requests. Will return 429 Too Many Requests until the lock is cleared.
• Fixed more ESI regex issues and added more tests.

v1.13

*Bugfix: Fixed greedy regex on ESI conditionals

v1.12

• Bugfix: Greedy regex for esi:include
• Feature: Made keyspace scan count configurable (and bump default to 1000).

v1.11

Feature: Added an ESI recursion limit.

v1.10

Feature: Added esi_pre_include_callback config option.
Bugfix: Better error handling for user supplied callbacks.

v1.09

Bugfix: Ensure uri spaces are re-encoded before requesting upstream (they are decoded by nginx)

v1.08

Bugfix: Avoid silently serving bodies for HEAD requests and 304 responses.
Bugfix: Fixed esi processing corner case accidentally disabled by 0227b23