Commit c49bba8a authored by Mac Newbold's avatar Mac Newbold
Browse files

General update, and add defs for swapping, idleswap, autoswap, etc. Also

added what we check for activity, and changed things from "24 hours" and
such to "several hours" and "a few hours".
parent 0c8e5e17
......@@ -13,6 +13,14 @@
What are your policies?</a>
<li><a href="#active">
What is "active use"?</a>
<li><a href="#idleness">
When is an experiment considered idle?</a>
<li><a href="#swapping">
What is "swapping"?</a>
<li><a href="#idleswap">
What is an "Idle-Swap"?</a>
<li><a href="#autoswap">
What is an "Auto-Swap"?</a>
<li><a href="#idle">
How long is too long for a node to be idle?</a>
<li><a href="#state">
......@@ -54,6 +62,69 @@ will be running, sending and receiving packets, and performing the
operations necessary to carry out the experiment.
<a name="idleness"></a>
<h3>When is an experiment considered idle?</h3>
Your experiment will be considered idle if it has no mesurable
activity for a significant period of time (a few hours).
We detect the following types of activity:
<li>Any Network activity on the experimental network
<li>Substantial activity on the control network
<li>TTY/console activity on nodes
<li>High CPU activity on nodes
<li>Certain external events, like rebooting a node with <tt>node_reboot</tt>
If your experiment's activity falls outside these measurable types
of activity, please be sure to let us know when you create your
experiment, or you may be swapped out unexpectedly.
<a name="swapping"></a>
<h3>What is "swapping"?</h3>
Swapping is the process of instantiating your experiment,
i.e. allocating nodes, configuring links, etc. It also refers
to the reverse process, where nodes are released. These are
called "swapping in" and "swapping out" respectively. See also
the <A href="docwrapper.php3?docname=faq.html#UTT-Swapping">
What is Swapping?</a> question on our FAQ.
<a name="idleswap"></a>
<h3>What is an "Idle-Swap"?</h3>
An "Idle-Swap" is when Emulab or its administrators swap your
experiment out for you because it was idle for too long.
Experiments typically don't get idle-swapped until they've been
idle for several hours. We try to contact the experiment creator
before swapping, unless they've already given us permission to
swap the experiment when idle.
<a name="autoswap"></a>
<h3>What is an "Auto-Swap"?</h3>
An "Auto-Swap" is when Emulab or its administrators swap your
experiment out because it was swapped in for longer than its specified
time limit. Emulab allows users to schedule experiment swapouts, to
aid experimenters in releasing nodes in a timely manner. For
instance, if you plan to use your experiment throughout an 8 hour work
day, you can schedule a swapout for 8 hours after it is swapped
in. That way, if you forget to swap out before leaving for the day, it
will automatically be taken care of for you, without leaving the nodes
reserved and idle for several hours before being idle-swapped. For
automated experiments, it can also help by letting you schedule an
auto-swap for just after the maximum amount of time your experiment
should last. You will typically receive a warning message about any
upcoming auto-swaps about an hour before they occur, to give you a
chance to readjust the timing for your auto-swap.
<a name="idle"></a>
<h3>How long is too long for a node to be idle?</h3>
......@@ -130,15 +201,20 @@ experiment.</h3>
Emulab has a system for detecting node use, to help achieve more
efficient and fair use of Emulab's limited resources. This system
sends email messages to experiment leaders whose experiments have been
idle for over 24 hours. If you get a message like this, your
idle for several hours. If you get a message like this, your
experiment has been inactive for too long and should free up the nodes
it has allocated. If the experiment continues to be idle, more
reminders will be sent. On the third reminder and subsequent messages,
your project leader will be one of the recipients. If you feel you
receive the message in error, please respond to <a
reminders may be sent, and soon
your project leader will be one of the recipients.
After you have been notified, your experiment may be swapped at any
time, depending on current demand for nodes, and other factors.
If you feel you received the message in error, please respond to <a
href=""> Testbed Operations
(</a> as soon as possible, describing how
you have used your node in the last 24 hours. There are some types of
you have used your node in the last few hours. There are some types of
activity that are difficult to accurately detect, so we'd like to know
how we can improve our activity detection system. Above all, <b>do not
ignore these messages</b>. If you get several reminders and don't
......@@ -153,7 +229,7 @@ inadvertently cause problems for you.
As described above, we will typically try to contact you about your
idle experiment before we swap it out. However, if the experiment has
been idle for many hours, we may swap it out for you unless you marked
been idle for several hours, we may swap it out for you unless you marked
it as "unswappable" when you created your experiment. Because of this,
it is critical that you keep in close contact with us about an
experiment that we may perceive as idle if you want to avoid any loss
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