##// END OF EJS Templates
httppeer: remove support for connecting to <0.9.1 servers (BC)...
httppeer: remove support for connecting to <0.9.1 servers (BC) Previously, HTTP wire protocol clients would attempt a "capabilities" wire protocol command. If that failed, they would fall back to issuing a "between" command. The "capabilities" command was added in Mercurial 0.9.1 (released July 2006). The "between" command has been present for as long as the wire protocol has existed. So if the "between" command failed, it was safe to assume that the remote could not speak any version of the Mercurial wire protocol. The "between" fallback was added in 395a84f78736 in 2011. Before that changeset, Mercurial would *always* issue the "between" command and would issue "capabilities" if capabilities were requested. At that time, many connections would issue "capabilities" eventually, so it was decided to issue "capabilities" by default and fall back to "between" if that failed. This saved a round trip when connecting to modern servers while still preserving compatibility with legacy servers. Fast forward ~7 years. Mercurial servers supporting "capabilities" have been around for over a decade. If modern clients are connecting to <0.9.1 servers, they are getting a bad experience. They may even be getting bad data (an old server is vulnerable to numerous security issues and could have been p0wned, leading to a Mercurial repository serving backdoors or other badness). In addition, the fallback can harm experience for modern servers. If a client experiences an intermittent HTTP request failure (due to bad network, etc) and falls back to a "between" that works, it would assume an empty capability set and would attempt to communicate with the repository using a very ancient wire protocol. Auditing HTTP logs for hg.mozilla.org, I did find a handful of requests for the null range of the "between" command. However, requests can be days apart. And when I do see requests, they come in batches. Those batches seem to correlate to spikes of HTTP 500 or other server/network events. So I think these requests are fallbacks from failed "capabilities" requests and not from old clients. If you need even more evidence to discontinue support, apparently we have no test coverage for communicating with servers not supporting "capabilities." I know this because all tests pass with the "between" fallback removed. Finally, server-side support for <0.9.1 pushing (the "addchangegroup" wire protocol command along with locking-related commands) was dropped from the HTTP client in fda0867cfe03 in 2017 and the SSH client in 9f6e0e7ef828 in 2015. I think this all adds up to enough justification for removing client support for communicating with servers not supporting "capabilities." So this commit removes that fallback. Differential Revision: https://phab.mercurial-scm.org/D2001

File last commit:

r25969:7b200566 default
r35902:197d10e1 default
Show More
pushkey.py
61 lines | 1.7 KiB | text/x-python | PythonLexer
Matt Mackall
pushkey: add pushkey core
r11367 # pushkey.py - dispatching for pushing and pulling keys
#
# Copyright 2010 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
Gregory Szorc
pushkey: use absolute_import
r25969 from __future__ import absolute_import
from . import (
bookmarks,
encoding,
obsolete,
phases,
)
Matt Mackall
bookmarks: move pushkey functions into core
r13353
Matt Mackall
pushkey: add pushkey core
r11367 def _nslist(repo):
n = {}
for k in _namespaces:
n[k] = ""
Durham Goode
obsolete: add exchange option...
r22953 if not obsolete.isenabled(repo, obsolete.exchangeopt):
Pierre-Yves David
pushkey: do not exchange obsole markers if feature is disabled...
r17298 n.pop('obsolete')
Matt Mackall
pushkey: add pushkey core
r11367 return n
Matt Mackall
bookmarks: move pushkey functions into core
r13353 _namespaces = {"namespaces": (lambda *x: False, _nslist),
Pierre-Yves David
phases: add basic pushkey support
r15648 "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
"phases": (phases.pushphase, phases.listphases),
Pierre-Yves.David@ens-lyon.org
obsolete: exchange obsolete marker over pushkey...
r17075 "obsolete": (obsolete.pushmarker, obsolete.listmarkers),
Pierre-Yves David
phases: add basic pushkey support
r15648 }
Matt Mackall
pushkey: add pushkey core
r11367
def register(namespace, pushkey, listkeys):
_namespaces[namespace] = (pushkey, listkeys)
def _get(namespace):
return _namespaces.get(namespace, (lambda *x: False, lambda *x: {}))
def push(repo, namespace, key, old, new):
'''should succeed iff value was old'''
pk = _get(namespace)[0]
return pk(repo, key, old, new)
def list(repo, namespace):
'''return a dict'''
lk = _get(namespace)[1]
return lk(repo)
Pierre-Yves David
pushkey: add an ``encode`` function...
r21661 encode = encoding.fromlocal
Pierre-Yves David
pushkey: add a ``decode`` function...
r21659 decode = encoding.tolocal
Pierre-Yves David
pushkey: introduce an ``encodekeys`` function...
r21650 def encodekeys(keys):
"""encode the content of a pushkey namespace for exchange over the wire"""
Pierre-Yves David
pushkey: add an ``encode`` function...
r21661 return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys])
Pierre-Yves David
pushkey: introduce an ``decodekeys`` function...
r21652
def decodekeys(data):
"""decode the content of a pushkey namespace from exchange over the wire"""
result = {}
for l in data.splitlines():
k, v = l.split('\t')
Pierre-Yves David
pushkey: add a ``decode`` function...
r21659 result[decode(k)] = decode(v)
Pierre-Yves David
pushkey: introduce an ``decodekeys`` function...
r21652 return result