[Varnish] #1294: Varnish diagrams don't mention hash_always_miss

[Varnish]

#1294: Varnish diagrams don't mention hash_always_miss
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 Reporter:  allanc  |       Type:  documentation
   Status:  new     |   Priority:  normal
Milestone:          |  Component:  build
  Version:  trunk   |   Severity:  normal
 Keywords:          |
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 [https://www.varnish-cache.org/trac/wiki/VCLExampleDefault This diagram]
 which provides a good overview of how Varnish works through the request-
 response handling workflow doesn't include any mention of
 "hash_always_miss".

 Looking at the diagram, I had been working under the assumption that
 Varnish didn't provide a way to update a cached document during a request
 without either purging it before reaching "vcl_fetch", or letting the
 cache object manually expire.

 It would be good if that diagram could include:
  * A change to the "obj in cache" block to show the influence that setting
 hash_always_miss has.
  * A clearer indication at what point the previously cached object is
 evacuated from the cache - presumably that happens at the point we choose
 to return "deliver" from "vcl_fetch", but it would be good if that was
 made explicit.

-- 
Ticket URL: <https://www.varnish-cache.org/trac/ticket/1294>
Varnish <https://varnish-cache.org/>
The Varnish HTTP Accelerator