Bug 40852 - Limit simultaneous DNS prefetch request number
Summary: Limit simultaneous DNS prefetch request number
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Platform (show other bugs)
Version: 528+ (Nightly build)
Hardware: Mac All
: P2 Normal
Assignee: Alexey Proskuryakov
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2010-06-18 13:29 PDT by Alexey Proskuryakov
Modified: 2010-06-18 14:06 PDT (History)
3 users (show)

See Also:


Attachments
proposed fix (3.71 KB, patch)
2010-06-18 13:46 PDT, Alexey Proskuryakov
ggaren: review+
Details | Formatted Diff | Diff

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Description Alexey Proskuryakov 2010-06-18 13:29:59 PDT
We currently queue up to 64 requests, and fire them all at once. Making 64 requests at once can overwhelm some routers.

<rdar://problem/8105498>
Comment 1 Alexey Proskuryakov 2010-06-18 13:46:12 PDT
Created attachment 59150 [details]
proposed fix
Comment 2 Darin Adler 2010-06-18 13:48:16 PDT
Comment on attachment 59150 [details]
proposed fix

Using a HashSet means the order of the names is based on hash table ordering, essentially random. Should we do something to preserve the order?
Comment 3 Geoffrey Garen 2010-06-18 13:55:44 PDT
Comment on attachment 59150 [details]
proposed fix

r=me

How did you test that this scheme does not overwhelm important gateways?
Comment 4 David Levin 2010-06-18 13:57:07 PDT
Since you are fixing the comment on line 58 of WebCore/platform/network/cf/DNSCFNet.cpp, maybe you can fix a spelling error as well "appications'".
Comment 5 Alexey Proskuryakov 2010-06-18 13:59:32 PDT
I am not aware of a strong reason why ordering would be important (my comment in code about dropping newer names notwithstanding).

> How did you test that this scheme does not overwhelm important gateways?

We know that chromium uses 8 parallel requests (because it has 8 loader threads), so I'm relying on matching them. Also, a co-worker seems to be able to reproduce the problem, so we'll test to see if a nightly resolves it.
Comment 6 Alexey Proskuryakov 2010-06-18 14:06:38 PDT
Committed <http://trac.webkit.org/changeset/61435>.