Yelp Frontpage / Common Questions (was Re: What are we doing wrong?)

[Matthew East]

Shaun,

On Wed, Jan 20, 2010 at 3:30 PM, Shaun McCance <shaunm at gnome.org> wrote:
> So there are two things to look at when talking about speed:
> 1) How long it takes Yelp to start up, and
> 2) How long it takes Yelp to transform a document.

First of all, thanks very much for your comments which are interesting
and encouraging at the same time. Much appreciated.

> For (1), we unfortunately had some regressions a few releases
> back because of eagerness to kill ScrollKeeper.  Long long ago,
> I worked pretty hard to ensure that Yelp doesn't do any sort
> of blocking operations on startup.  So stuff like finding all
> installed documentation happened in an idle loop.  With the
> switch to Rarian, finding installed documentation now blocks
> Yelp startup.  This is a problem, and it will be fixed.

Good to know - thanks. We will watch the changelog!

> Note also that in 3.0, the default front page of Yelp will be
> the Desktop Help, which I think is closer to what Ubuntu has
> already patched Yelp to do anyway.  So it doesn't really make
> sense to block on the list of installed documentation when
> you don't even see that page by default.

Absolutely - indeed we don't show that page anywhere, although I
believe it is possible to access it manually by entering a special
address. If you have any tips on how to disable this activity at
startup, then that would be awesome.

> We also have to consider Mallard documents for (2).  Mallard
> documents are always processing one page at a time, so that
> particular source of problems is gone.  But Yelp does have
> to read all the pages to know what links to what.  Lots of
> small file reads is never a good idea.  So I want to try
> installing Mallard Cache files along with the pages.  This
> is not all that difficult.  It just takes a bit of hacking
> time on my part.

That sounds like a cool idea.

> As for search, Yelp has two backends: one using Beagle, and
> one that's basically a glorified grep.  The grep backend is
> going to thrash your disk.  I don't know which one is used
> by default on Ubuntu.  But Beagle is a dead project, so we
> need to look elsewhere for Yelp's future.  I've spoken to
> some Tracker developers, and I'd like to work on using it
> for Yelp's search backend.  Again, hacking time.

Again, cool - we'll keep our eyes open.

Thanks again for the explanations.

-- 
Matthew East
http://www.mdke.org
gnupg pub 1024D/0E6B06FF