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diff --git a/README/index.html b/README/index.html index 172692da5..7e37211f5 100644 --- a/README/index.html +++ b/README/index.html @@ -938,13 +938,111 @@ resolve the situation.</p></div> <span class="na">mergeoptions</span> <span class="o">=</span> <span class="s">--ff-only</span> </pre></div></div></div> </div> +<div class="sect2"> +<h3 id="_set_up_ssh_mulitplexing_for_speed">2.6. Set up SSH Mulitplexing for Speed</h3> +<div class="paragraph"><p>This is one of my most convenient tricks. The slowest parts of <tt>git pull</tt> and +<tt>git push</tt> are starting up the SSH connection. However, there is a way to +eliminate this problem simply by opening a persistent tunnel, which <tt>git pull</tt> +and <tt>git push</tt> automatically reuse.</p></div> +<div class="sect3"> +<h4 id="_ssh_config">2.6.1. ~/.ssh/config</h4> +<div class="paragraph"><p>Enter the ControlMaster option for OpenSSH.</p></div> +<div class="quoteblock"> +<div class="content"> +<div class="paragraph"><p><strong>ControlMaster</strong></p></div> +<div class="paragraph"><p>Enables the sharing of multiple sessions over a single network connection. +When set to “yes”, ssh(1) will listen for connections on a control socket +specified using the ControlPath argument. Additional sessions can connect to +this socket using the same <strong>ControlPath</strong> with <strong>ControlMaster</strong> set to “no” +(the default).</p></div> +<div class="paragraph"><p>These sessions will try to reuse the master instance’s network connection +rather than initiating new ones, but will fall back to connecting normally if +the control socket does not exist, or is not listening.</p></div> +<div class="paragraph"><p>Setting this to “ask” will cause ssh to listen for control connections, but +require confirmation using the SSH_ASKPASS program before they are accepted +(see ssh-add(1) for details). If the <strong>ControlPath</strong> cannot be opened, ssh will +continue without connecting to a master instance.</p></div> +<div class="paragraph"><p>X11 and ssh-agent(1) forwarding is supported over these multiplexed +connections, however the display and agent forwarded will be the one belonging +to the master connection i.e. it is not possible to forward multiple displays +or agents.</p></div> +<div class="paragraph"><p>Two additional options allow for opportunistic multiplexing: try to use a +master connection but fall back to creating a new one if one does not already +exist. These options are: “auto” and “autoask”. The latter requires +confirmation like the “ask” option.</p></div> +</div> +<div class="attribution"> +</div></div> +<div class="paragraph"><p>So I set up my ~/.ssh/config as follows.</p></div> +<div class="listingblock"> +<div class="content"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1 +2 +3 +4 +5 +6</pre></div></td><td class="code"><div class="highlight"><pre><span class="c">#~/.ssh/config</span> +ControlMaster auto +ControlPath ~/.ssh/pool/%r@%h +ServerAliveCountMax 6 +ServerAliveInterval 10 +TCPKeepAlive yes +</pre></div> +</td></tr></table></div></div> +<div class="paragraph"><p>And we’re set!.</p></div> +</div> +<div class="sect3"> +<h4 id="_first_a_few_benchmarks">2.6.2. First, a few benchmarks</h4> +<div class="paragraph"><p>First, lets see how fast it is without the magic:</p></div> +<div class="listingblock"> +<div class="content"><div class="highlight"><pre>> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch github; <span class="k">done</span> + +real 0m47.798s +user 0m0.226s +sys 0m0.236s + +> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch origin; <span class="k">done</span> + +real 0m48.444s +user 0m0.235s +sys 0m0.250s +</pre></div></div></div> +<div class="paragraph"><p>Averaging about 4.34s per fetch to Github, 4.40s to gentoo overlays.</p></div> +<div class="paragraph"><p>SLOOW.</p></div> +</div> +<div class="sect3"> +<h4 id="_start_a_background_connection">2.6.3. Start a background connection</h4> +<div class="paragraph"><p>With ControlMaster, you set up a long-lived SSH connection.</p></div> +<div class="listingblock"> +<div class="content"><div class="highlight"><pre>> ssh -fNn git@github.com +> ssh -fNn git@git.overlays.gentoo.org +</pre></div></div></div> +<div class="paragraph"><p>And we’re truely really to start cooking with petrol.</p></div> +</div> +<div class="sect3"> +<h4 id="_post_configuration_benchmarks">2.6.4. Post Configuration Benchmarks</h4> +<div class="listingblock"> +<div class="content"><div class="highlight"><pre>> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch github; <span class="k">done</span> + +real 0m12.935s +user 0m0.093s +sys 0m0.193s + +> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch origin; <span class="k">done</span> + +real 0m11.597s +user 0m0.099s +sys 0m0.191s +</pre></div></div></div> +<div class="paragraph"><p>O_o. Averaging about 1.175s and 1.05s respectively.</p></div> +</div> +</div> </div> </div> </div> <div id="footnotes"><hr/></div> <div id="footer"> <div id="footer-text"> -Last updated 2010-09-29 13:27:58 NZDT +Last updated 2010-09-29 14:37:13 NZDT </div> <div id="footer-badges"> <a href="http://validator.w3.org/check?uri=referer"> diff --git a/README/index.txt b/README/index.txt index ed4518e4b..c4f04dd52 100644 --- a/README/index.txt +++ b/README/index.txt @@ -14,3 +14,4 @@ include::src/git/contribution-order.txt[] include::src/git/linearize-commits.txt[] include::src/git/work-in-a-branch.txt[] include::src/git/disable-merge-pull.txt[] +include::src/git/ssh-multiplex.txt[] diff --git a/README/src/git/ssh-multiplex.html b/README/src/git/ssh-multiplex.html new file mode 100644 index 000000000..7fdcef13f --- /dev/null +++ b/README/src/git/ssh-multiplex.html @@ -0,0 +1,724 @@ +<?xml version="1.0"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> +<head> +<meta http-equiv="Content-Type" content="application/xhtml+xml; 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The slowest parts of <tt>git pull</tt> and +<tt>git push</tt> are starting up the SSH connection. However, there is a way to +eliminate this problem simply by opening a persistent tunnel, which <tt>git pull</tt> +and <tt>git push</tt> automatically reuse.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_ssh_config">1. ~/.ssh/config</h2> +<div class="sectionbody"> +<div class="paragraph"><p>Enter the ControlMaster option for OpenSSH.</p></div> +<div class="quoteblock"> +<div class="content"> +<div class="paragraph"><p><strong>ControlMaster</strong></p></div> +<div class="paragraph"><p>Enables the sharing of multiple sessions over a single network connection. +When set to “yes”, ssh(1) will listen for connections on a control socket +specified using the ControlPath argument. Additional sessions can connect to +this socket using the same <strong>ControlPath</strong> with <strong>ControlMaster</strong> set to “no” +(the default).</p></div> +<div class="paragraph"><p>These sessions will try to reuse the master instance’s network connection +rather than initiating new ones, but will fall back to connecting normally if +the control socket does not exist, or is not listening.</p></div> +<div class="paragraph"><p>Setting this to “ask” will cause ssh to listen for control connections, but +require confirmation using the SSH_ASKPASS program before they are accepted +(see ssh-add(1) for details). If the <strong>ControlPath</strong> cannot be opened, ssh will +continue without connecting to a master instance.</p></div> +<div class="paragraph"><p>X11 and ssh-agent(1) forwarding is supported over these multiplexed +connections, however the display and agent forwarded will be the one belonging +to the master connection i.e. it is not possible to forward multiple displays +or agents.</p></div> +<div class="paragraph"><p>Two additional options allow for opportunistic multiplexing: try to use a +master connection but fall back to creating a new one if one does not already +exist. These options are: “auto” and “autoask”. The latter requires +confirmation like the “ask” option.</p></div> +</div> +<div class="attribution"> +</div></div> +<div class="paragraph"><p>So I set up my ~/.ssh/config as follows.</p></div> +<div class="listingblock"> +<div class="content"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1 +2 +3 +4 +5 +6</pre></div></td><td class="code"><div class="highlight"><pre><span class="c">#~/.ssh/config</span> +ControlMaster auto +ControlPath ~/.ssh/pool/%r@%h +ServerAliveCountMax 6 +ServerAliveInterval 10 +TCPKeepAlive yes +</pre></div> +</td></tr></table></div></div> +<div class="paragraph"><p>And we’re set!.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_first_a_few_benchmarks">2. First, a few benchmarks</h2> +<div class="sectionbody"> +<div class="paragraph"><p>First, lets see how fast it is without the magic:</p></div> +<div class="listingblock"> +<div class="content"><div class="highlight"><pre>> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch github; <span class="k">done</span> + +real 0m47.798s +user 0m0.226s +sys 0m0.236s + +> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch origin; <span class="k">done</span> + +real 0m48.444s +user 0m0.235s +sys 0m0.250s +</pre></div></div></div> +<div class="paragraph"><p>Averaging about 4.34s per fetch to Github, 4.40s to gentoo overlays.</p></div> +<div class="paragraph"><p>SLOOW.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_start_a_background_connection">3. Start a background connection</h2> +<div class="sectionbody"> +<div class="paragraph"><p>With ControlMaster, you set up a long-lived SSH connection.</p></div> +<div class="listingblock"> +<div class="content"><div class="highlight"><pre>> ssh -fNn git@github.com +> ssh -fNn git@git.overlays.gentoo.org +</pre></div></div></div> +<div class="paragraph"><p>And we’re truely really to start cooking with petrol.</p></div> +</div> +</div> +<div class="sect1"> +<h2 id="_post_configuration_benchmarks">4. Post Configuration Benchmarks</h2> +<div class="sectionbody"> +<div class="listingblock"> +<div class="content"><div class="highlight"><pre>> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch github; <span class="k">done</span> + +real 0m12.935s +user 0m0.093s +sys 0m0.193s + +> <span class="nb">time </span><span class="k">for </span>i in <span class="k">$(</span> seq 0 10 <span class="k">)</span> ; <span class="k">do </span>git fetch origin; <span class="k">done</span> + +real 0m11.597s +user 0m0.099s +sys 0m0.191s +</pre></div></div></div> +<div class="paragraph"><p>O_o. Averaging about 1.175s and 1.05s respectively.</p></div> +</div> +</div> +</div> +<div id="footnotes"><hr/></div> +<div id="footer"> +<div id="footer-text"> +Last updated 2010-09-29 16:52:25 NZDT +</div> +<div id="footer-badges"> +<a href="http://validator.w3.org/check?uri=referer"> + <img style="border:0;width:88px;height:31px" src="http://www.w3.org/Icons/valid-xhtml11-blue" alt="Valid XHTML 1.1" height="31" width="88"/> +</a> +<a href="http://jigsaw.w3.org/css-validator/"> + <img style="border:0;width:88px;height:31px" src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS!"/> +</a> +<a href="http://www.mozilla.org/products/firefox/"> + <img style="border:none; width:110px; height:32px;" src="http://www.spreadfirefox.com/community/images/affiliates/Buttons/110x32/safer.gif" alt="Get Firefox!"/> +</a> +</div> +</div> +</body> +</html> diff --git a/README/src/git/ssh-multiplex.txt b/README/src/git/ssh-multiplex.txt new file mode 100644 index 000000000..43f58bfb9 --- /dev/null +++ b/README/src/git/ssh-multiplex.txt @@ -0,0 +1,113 @@ +Set up SSH Mulitplexing for Speed +================================= + +This is one of my most convenient tricks. The slowest parts of `git pull` and +`git push` are starting up the SSH connection. However, there is a way to +eliminate this problem simply by opening a persistent tunnel, which `git pull` +and `git push` automatically reuse. + +~/.ssh/config +------------- + +Enter the ControlMaster option for OpenSSH. + +_________________________ +*ControlMaster* + +Enables the sharing of multiple sessions over a single network connection. +When set to “yes”, ssh(1) will listen for connections on a control socket +specified using the ControlPath argument. Additional sessions can connect to +this socket using the same *ControlPath* with *ControlMaster* set to “no” +(the default). + +These sessions will try to reuse the master instance's network connection +rather than initiating new ones, but will fall back to connecting normally if +the control socket does not exist, or is not listening. + +Setting this to “ask” will cause ssh to listen for control connections, but +require confirmation using the SSH_ASKPASS program before they are accepted +(see ssh-add(1) for details). If the *ControlPath* cannot be opened, ssh will +continue without connecting to a master instance. + +X11 and ssh-agent(1) forwarding is supported over these multiplexed +connections, however the display and agent forwarded will be the one belonging +to the master connection i.e. it is not possible to forward multiple displays +or agents. + +Two additional options allow for opportunistic multiplexing: try to use a +master connection but fall back to creating a new one if one does not already +exist. These options are: “auto” and “autoask”. The latter requires +confirmation like the “ask” option. +_________________________ + +So I set up my ~/.ssh/config as follows. + +[source,bash,numbered] +#~/.ssh/config +ControlMaster auto +ControlPath ~/.ssh/pool/%r@%h +ServerAliveCountMax 6 +ServerAliveInterval 10 +TCPKeepAlive yes + +And we're set!. + +First, a few benchmarks +----------------------- + +First, lets see how fast it is without the magic: + +[source,bash] +------ +> time for i in $( seq 0 10 ) ; do git fetch github; done + +real 0m47.798s +user 0m0.226s +sys 0m0.236s + +> time for i in $( seq 0 10 ) ; do git fetch origin; done + +real 0m48.444s +user 0m0.235s +sys 0m0.250s +------ + +Averaging about 4.34s per fetch to Github, 4.40s to gentoo overlays. + +SLOOW. + +Start a background connection +----------------------------- + +With ControlMaster, you set up a long-lived SSH connection. + +[source,bash] +------ +> ssh -fNn git@github.com +> ssh -fNn git@git.overlays.gentoo.org +------ + +And we're truely really to start cooking with petrol. + +Post Configuration Benchmarks +----------------------------- + +[source,bash] +------ +> time for i in $( seq 0 10 ) ; do git fetch github; done + +real 0m12.935s +user 0m0.093s +sys 0m0.193s + +> time for i in $( seq 0 10 ) ; do git fetch origin; done + +real 0m11.597s +user 0m0.099s +sys 0m0.191s +------ + +O_o. Averaging about 1.175s and 1.05s respectively. + + + |