From: Petr Baudis <pasky@suse.cz>
To: Jakub Narebski <jnareb@gmail.com>
Cc: git@vger.kernel.org,
John 'Warthog9' Hawley <warthog9@eaglescrag.net>,
John 'Warthog9' Hawley <warthog9@kernel.org>
Subject: Re: [RFC PATCH 10/10] gitweb: Show appropriate "Generating..." page when regenerating cache (WIP)
Date: Mon, 25 Jan 2010 14:56:53 +0100 [thread overview]
Message-ID: <20100125135653.GN4159@machine.or.cz> (raw)
In-Reply-To: <201001251448.27513.jnareb@gmail.com>
On Mon, Jan 25, 2010 at 02:48:26PM +0100, Jakub Narebski wrote:
> Now those patches (mine and J.H. both) make gitweb use locking
> (it is IIRC configurable in J.H. patch) to make only one process
> generate the page if it is missing from cache, or is stale. Now
> if it is missing, we have to wait until it is generated in full
> before being able to show it to client. While it is possible to
> "tee" output (using PerlIO::tee, or Capture::Tiny, or tie like
> CGI::Cache) writing it simultaneously to browser and to cache for
> the process that is generating data, it is as far as I understand
> it impossible for processes which are waiting for data. Therefore
> the need for "Generating..." page, so the user does not think that
> web server hung or something, and is not generating output.
Ah, ok, so the message is there to cover up for a technical problem. ;-)
I didn't quite realize. Then, it would be great to tweak the mechanisms
so that the user does not really have to wait.
So, I wonder about two things:
(i) How often does it happen that two requests for the same page are
received? Has anyone measured it? Or is at least able to make
a minimally educated guess? IOW, isn't this premature optimization?
(ii) Can't the locked gitwebs do the equivalent of tail -f?
P.S.: Again the disclaimer - if this is "too hard", it's better to
accept patches like they are, then improve this later. But perhaps
a better solution would be not to clutter the code by optimizing this
case at all if it's not clear it really matters in the real world.
Petr "Pasky" Baudis
next prev parent reply other threads:[~2010-01-25 13:57 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-14 1:22 [PATCH 0/9] Gitweb caching v5 John 'Warthog9' Hawley
2010-01-14 1:22 ` [PATCH 1/9] gitweb: Load checking John 'Warthog9' Hawley
2010-01-14 1:22 ` [PATCH 2/9] gitweb: change die_error to take "extra" argument for extended die information John 'Warthog9' Hawley
2010-01-14 1:22 ` [PATCH 3/9] gitweb: Add option to force version match John 'Warthog9' Hawley
2010-01-14 1:23 ` [PATCH 4/9] gitweb: Makefile improvements John 'Warthog9' Hawley
2010-01-14 1:23 ` [PATCH 5/9] gitweb: add a get function to compliment print_local_time John 'Warthog9' Hawley
2010-01-14 1:23 ` [PATCH 6/9] gitweb: add a get function to compliment print_sort_th John 'Warthog9' Hawley
2010-01-14 1:23 ` [PATCH 7/9] gitweb: cleanup error message produced by undefined $site_header John 'Warthog9' Hawley
2010-01-14 1:23 ` [PATCH 8/9] gitweb: Convert output to using indirect file handle John 'Warthog9' Hawley
2010-01-14 1:23 ` [PATCH 9/9] gitweb: File based caching layer (from git.kernel.org) John 'Warthog9' Hawley
2010-01-16 2:48 ` Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 00/10] gitweb: Simple file based output caching Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 02/10] gitweb: href(..., -path_info => 0|1) Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 03/10] gitweb/cache.pm - Very simple file based caching Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 04/10] gitweb/cache.pm - Stat-based cache expiration Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 05/10] gitweb: Use Cache::Cache compatibile (get, set) output caching (WIP) Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 06/10] gitweb/cache.pm - Adaptive cache expiration time (WIP) Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 07/10] gitweb: Use CHI compatibile (compute method) caching (WIP) Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 08/10] gitweb/cache.pm - Use locking to avoid 'stampeding herd' problem (WIP) Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 09/10] gitweb/cache.pm - Serve stale data when waiting for filling cache (WIP) Jakub Narebski
2010-01-23 0:27 ` [RFC PATCH 10/10] gitweb: Show appropriate "Generating..." page when regenerating " Jakub Narebski
2010-01-24 22:24 ` Petr Baudis
2010-01-25 0:03 ` Jakub Narebski
2010-01-25 1:17 ` Jakub Narebski
2010-01-25 11:46 ` Jakub Narebski
2010-01-25 13:02 ` Petr Baudis
2010-01-25 13:48 ` Jakub Narebski
2010-01-25 13:56 ` Petr Baudis [this message]
2010-01-25 20:32 ` J.H.
2010-01-26 1:49 ` Jakub Narebski
2010-01-28 17:39 ` Petr Baudis
2010-01-31 11:58 ` Jakub Narebski
2010-01-25 20:58 ` Jakub Narebski
2010-01-25 20:41 ` J.H.
2010-01-26 2:30 ` Jakub Narebski
2010-01-23 19:55 ` [RFC PATCH 00/10] gitweb: Simple file based output caching J.H.
2010-01-24 13:54 ` [RFC PATCH 11/10] gitweb: Ajax-y "Generating..." page when regenerating cache (WIP) Jakub Narebski
2010-02-06 0:51 ` [RFC PATCH 00/10] gitweb: Simple file based output caching J.H.
2010-02-06 23:56 ` Jakub Narebski
2010-02-07 12:35 ` Jakub Narebski
[not found] ` <0dd15cb3f18e2a26fc834fd3b071e6d3ecc00557.1264198194.git.jnareb@gmail.com>
2010-01-23 0:48 ` [RFC PATCH 01/10] gitweb: Print to explicit filehandle (preparing for caching) Jakub Narebski
2010-02-07 21:32 ` Jakub Narebski
2010-01-16 0:43 ` [PATCH 8/9] gitweb: Convert output to using indirect file handle Jakub Narebski
2010-01-16 0:58 ` Junio C Hamano
2010-01-16 1:14 ` Jakub Narebski
2010-01-16 1:41 ` Junio C Hamano
2010-01-24 22:14 ` Petr Baudis
2010-01-25 1:47 ` Jakub Narebski
2010-01-25 20:48 ` J.H.
2010-01-25 21:48 ` Jakub Narebski
2010-01-15 23:49 ` [PATCH 7/9] gitweb: cleanup error message produced by undefined $site_header Jakub Narebski
2010-01-23 11:13 ` [PATCH 5/9] gitweb: add a get function to compliment print_local_time Jakub Narebski
2010-01-15 23:36 ` [PATCH 3/9] gitweb: Add option to force version match Jakub Narebski
2010-01-24 21:59 ` Petr Baudis
2010-01-24 23:17 ` Jakub Narebski
2010-01-15 22:40 ` [PATCH 2/9] gitweb: change die_error to take "extra" argument for extended die information Jakub Narebski
2010-01-15 22:30 ` [PATCH 1/9] gitweb: Load checking Jakub Narebski
2010-01-15 1:40 ` [PATCH 0/9] Gitweb caching v5 Jakub Narebski
2010-01-15 4:29 ` J.H.
2010-01-15 10:28 ` Jakub Narebski
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