diff hgext/clonebundles.py @ 27738:a0e783d26e81

exchange: make clone bundles non-experimental and enabled by default

The clone bundles feature was introduced in Mercurial 3.6 behind an
experimental and disabled by default flag. The feature has been enabled
on hg.mozilla.org for a few months and has served many terabytes of
clones. Users have been encouraged to use the feature and reception
has been very positive (mainly due to faster clones as a result of
connecting to a CDN). I have heard no feedback about changing the
feature other than inquiries about when it will be enabled by default.
So, I think the feature is ready to be enabled by default.

This patch renames experimental.clonebundles to ui.clonebundles,
documents the option, and enables it by default. References to the
experimental state of clone bundles have been removed. The remaining
config option docs in clonebundles.py have been removed because they
are redudant with `hg help config`.

There are some oddities with behavior of clone bundles. Because clones
with clone bundles are effectively 2 `hg pull` operations, there may be
2 transactions. This could result in hooks running twice. If the
subsequent pull is aborted, it could result in partial rollback and an
incomplete clone. This behavior is a bit wonky and should probably
be documented. If this patch is accepted, I'll send a follow-up to
document it. I don't think this behavior should prevent the feature
being enabled by default. Reworking the clone mechanism to support
interrupted or multi-part clones feels like a major new feature and
something that when implemented can change the hook and rollback
semantics of clone bundles. Besides, partial clone is better than
full rollback and hooks running on initial clone are likely rare, so I
think the impact is minimal.

--- a/hgext/clonebundles.py	Fri Jan 08 10:57:01 2016 -0800
+++ b/hgext/clonebundles.py	Fri Jan 08 10:58:04 2016 -0800
@@ -1,7 +1,7 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
-"""advertise pre-generated bundles to seed clones (experimental)
+"""advertise pre-generated bundles to seed clones
 
 "clonebundles" is a server-side extension used to advertise the existence
 of pre-generated, externally hosted bundle files to clients that are
@@ -160,16 +160,6 @@
 occurs. So server operators should prepare for some people to follow these
 instructions when a failure occurs, thus driving more load to the original
 Mercurial server when the bundle hosting service fails.
-
-The following config options influence the behavior of the clone bundles
-feature:
-
-ui.clonebundlefallback
-   Whether to automatically fall back to a traditional clone in case of
-   clone bundles failure. Defaults to false for reasons described above.
-
-experimental.clonebundles
-   Whether the clone bundles feature is enabled on clients. Defaults to true.
 """
 
 from mercurial import (