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| author | jar@chromium.org <jar@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-10-29 06:33:59 +0000 |
|---|---|---|
| committer | jar@chromium.org <jar@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-10-29 06:33:59 +0000 |
| commit | 755a93358a4216c62c1055d1c33c45df8e1b7857 (patch) | |
| tree | a452f5d467b5fbc157cb4b213073063b142d9147 /net | |
| parent | dff8c1108d0b414ea73ae0e0d0d904e09856cdd6 (diff) | |
| download | chromium_src-755a93358a4216c62c1055d1c33c45df8e1b7857.zip chromium_src-755a93358a4216c62c1055d1c33c45df8e1b7857.tar.gz chromium_src-755a93358a4216c62c1055d1c33c45df8e1b7857.tar.bz2 | |
Restrict total parallel DNS resolutions
A/B tests suggest that large numbers of parallel
resolutions may cause the DNS failure rate
(re: ratio of "host not found" to "found") to
rise. To stay safely away from that threshold,
this change lowers the maximum parallel resolutions
to 8, and restricts the speculative resolutions
to 3.
We are also running A/B tests which will look at the
impact of modulating either of these values.
BUG=3041
r=eroman
Review URL: http://codereview.chromium.org/4111004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@64369 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'net')
| -rw-r--r-- | net/base/host_resolver_impl.cc | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/base/host_resolver_impl.cc b/net/base/host_resolver_impl.cc index 13dce85..3805979 100644 --- a/net/base/host_resolver_impl.cc +++ b/net/base/host_resolver_impl.cc @@ -74,9 +74,11 @@ HostCache* CreateDefaultCache() { HostResolver* CreateSystemHostResolver(size_t max_concurrent_resolves, HostResolverProc* resolver_proc, NetLog* net_log) { - // Maximum of 50 concurrent threads. - // TODO(eroman): Adjust this, do some A/B experiments. - static const size_t kDefaultMaxJobs = 50u; + // Maximum of 8 concurrent resolver threads. + // Some routers (or resolvers) appear to start to provide host-not-found if + // too many simultaneous resolutions are pending. This number needs to be + // further optimized, but 8 is what FF currently does. + static const size_t kDefaultMaxJobs = 8u; if (max_concurrent_resolves == HostResolver::kDefaultParallelism) max_concurrent_resolves = kDefaultMaxJobs; |