perfsonar-dev - nmwg: r308 - trunk/nmwg/doc/dLS
Subject: perfsonar development work
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- Subject: nmwg: r308 - trunk/nmwg/doc/dLS
- Date: Fri, 14 Dec 2007 06:12:30 -0500
Author: mac
Date: 2007-12-14 06:12:29 -0500 (Fri, 14 Dec 2007)
New Revision: 308
Modified:
trunk/nmwg/doc/dLS/dLS.html
trunk/nmwg/doc/dLS/dLS.pdf
trunk/nmwg/doc/dLS/dLS.xml
Log:
Leader election example sequence diagram added
Modified: trunk/nmwg/doc/dLS/dLS.html
===================================================================
--- trunk/nmwg/doc/dLS/dLS.html 2007-12-14 09:54:21 UTC (rev 307)
+++ trunk/nmwg/doc/dLS/dLS.html 2007-12-14 11:12:29 UTC (rev 308)
@@ -537,15 +537,36 @@
</div>
<p>Illustration of Leader Election Algorithm</p>
<pre>
-
- LS1 LS2 LS3
- | | |
- (...) (...) (...)
- | | |
-
+Token election
+
+ LS2 LS3 LS1
+ | | |
+1 o | |
+2 [#] ELECTING | |
+ [#] | |
+ [#] election (LS2) | |
+3 [#]--------------->[#] |
+ | [#] election (LS3) |
+4 | [#]--------------->[#]
+ | (LS3) election | [#]
+5 [#]<----------------+-----------------[#]
+6 [#] | |
+
</pre>
-<p>LS1, LS2 and LS3 are members of the ring.</p>
+<p>LS1, LS2 and LS3 are members of the ring. LS2 initiates Leader
Election</p>
<p class="figure">Figure 4</p>
+<p id="rfc.section.2.2.2.1.p.7">
+</p>
+<dl class="empty">
+<dd>1. LS2 decides to initiate election,</dd>
+<dd>2. LS2 changes its state to ELECTING</dd>
+<dd>3. LS2 sends election message (with its identifier) to LS3</dd>
+<dd>4. LS3 receives election message with identifier of LS1. Its own
identifier is higher, so it sends election message to next peer LS1 with ist
own identifier.</dd>
+<dd>5. LS1 receives election message with identifier of LS3. Its own
identifier is lower, so it sends election message to next peer LS2 with
identifier of LS3.</dd>
+<dd>6. LS2 receives election message with identifier of LS3, election
finishes. LS2 knows the leader is LS3. LS2 disable ELECTING state.</dd>
+</dl>
+<p id="rfc.section.2.2.2.1.p.8">Vice-leader election may be done using the
same algorithm. Then the election message should contain two identifiers:
Leader ID (the highest identifier) and Vice-Leader ID (the second highest
identifier).</p>
+<p id="rfc.section.2.2.2.1.p.9">======== MG: as far as I understand, all
members of the ring initiate own election, the result is always the same
(deterministic). If a peer initiates election and receives election message
with own identifier, it means that it is the new leader and should send new
token, right? Maybe after election, the peer that wasn't elected, should
inform the new leader? Or maybe another message passing over the ring is
required (this could be done with two states ELECTING and POST-ELECTION or
whatever).</p>
<h4 id="rfc.section.2.2.2.2">
<a href="#rfc.section.2.2.2.2">2.2.2.2</a> Token Passing for
Registration Control</h4>
<p id="rfc.section.2.2.2.2.p.1">The token can be viewed as "permission to
talk" and permits the holding LS to send its summary information to all other
available LS instances (see <a href="#LSControl-Summary-lower" title="LS
Summary Message (Lower)">Section 4.6</a> and <a
href="#LSControl-Summary-upper" title="LS Summary Message
(Upper)">Section 4.7</a>). The responses will be parsed to get any
useful updated information about current dLS cloud state.</p>
Modified: trunk/nmwg/doc/dLS/dLS.pdf
===================================================================
(Binary files differ)
Modified: trunk/nmwg/doc/dLS/dLS.xml
===================================================================
--- trunk/nmwg/doc/dLS/dLS.xml 2007-12-14 09:54:21 UTC (rev 307)
+++ trunk/nmwg/doc/dLS/dLS.xml 2007-12-14 11:12:29 UTC (rev 308)
@@ -436,16 +436,38 @@
<figure anchor="leader-election-example">
<preamble>Illustration of Leader Election Algorithm</preamble>
<artwork>
-
- LS1 LS2 LS3
- | | |
- (...) (...) (...)
- | | |
-
+Token election
+
+ LS2 LS3 LS1
+ | | |
+1 o | |
+2 [#] ELECTING | |
+ [#] | |
+ [#] election (LS2) | |
+3 [#]--------------->[#] |
+ | [#] election (LS3) |
+4 | [#]--------------->[#]
+ | (LS3) election | [#]
+5 [#]<----------------+-----------------[#]
+6 [#] | |
+
</artwork>
- <postamble>LS1, LS2 and LS3 are members of the ring.</postamble>
+ <postamble>LS1, LS2 and LS3 are members of the ring. LS2 initiates
Leader Election</postamble>
</figure>
+ <t>
+ <list type="symbols">
+ <t>1. LS2 decides to initiate election, </t>
+ <t>2. LS2 changes its state to ELECTING</t>
+ <t>3. LS2 sends election message (with its identifier) to LS3</t>
+ <t>4. LS3 receives election message with identifier of LS1. Its
own identifier is higher, so it sends election message to next peer LS1 with
ist own identifier.</t>
+ <t>5. LS1 receives election message with identifier of LS3. Its
own identifier is lower, so it sends election message to next peer LS2 with
identifier of LS3.</t>
+ <t>6. LS2 receives election message with identifier of LS3,
election finishes. LS2 knows the leader is LS3. LS2 disable ELECTING
state.</t>
+ </list>
+ </t>
+ <t>Vice-leader election may be done using the same algorithm. Then
the election message should contain two identifiers: Leader ID (the highest
identifier) and Vice-Leader ID (the second highest identifier).</t>
+
+ <t>======== MG: as far as I understand, all members of the ring
initiate own election, the result is always the same (deterministic). If a
peer initiates election and receives election message with own identifier, it
means that it is the new leader and should send new token, right? Maybe after
election, the peer that wasn't elected, should inform the new leader? Or
maybe another message passing over the ring is required (this could be done
with two states ELECTING and POST-ELECTION or whatever).</t>
</section>
<section title="Token Passing for Registration Control">
- nmwg: r308 - trunk/nmwg/doc/dLS, svnlog, 12/14/2007
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