Commit c98a75f9 authored by Mladen Turk's avatar Mladen Turk
Browse files

Add sample algorithm for scheduler and 

use <pre><code> for algorithm tables.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@106751 13f79535-47bb-0310-9956-ffa450edef68
parent f6b52359

docs/manual/mod/mod_proxy_balancer.html.en

+39 −82
Original line number Diff line number Diff line
@@ -80,95 +80,52 @@ load balancing </td></tr> 


    <p>If some workers are disabled, the others will

    still be scheduled correctly.</p>

    <div class="example"><pre>

for each worker in workers

    worker lbstatus += worker lbfactor

    total factor    += worker lbfactor

    if worker lbstatus &gt; candidate lbstatus

       candidate = worker



candidate lbstatus -= total factor



    </pre></div>

    <p>If a balancer is configured as follows:</p>

    

    <table><tr><th>worker</th>

        <th class="data">a</th>

        <th class="data">b</th>

        <th class="data">c</th>

        <th class="data">d</th></tr>

<tr><th>lbfactor</th>

        <td class="data">25</td>

        <td class="data">25</td>

        <td class="data">25</td>

        <td class="data">25</td></tr>

<tr><th>lbstatus</th>

        <td class="data">0</td>

        <td class="data">0</td>

        <td class="data">0</td>

        <td class="data">0</td></tr>

</table>

    <pre><code>

    worker     a    b    c    d

    lbfactor  25   25   25   25

    lbstatus   0    0    0    0

    </code></pre>



    <p>And <var>b</var> gets disabled, the following schedule is produced:</p>



    <table><tr><th>worker</th>

        <th class="data">a</th>

        <th class="data">b</th>

        <th class="data">c</th>

        <th class="data">d</th></tr>

<tr><th>lbstatus</th>

        <td class="data">-50</td>

        <td class="data">0</td>

        <td class="data">25</td>

        <td class="data">25</td></tr>

<tr><th>lbstatus</th>

        <td class="data">-25</td>

        <td class="data">0</td>

        <td class="data">-25</td>

        <td class="data">50</td></tr>

<tr><th>lbstatus</th>

        <td class="data">0</td>

        <td class="data">0</td>

        <td class="data">0</td>

        <td class="data">0</td></tr>

<tr><td class="data" colspan="5">(repeat)</td></tr>

</table>



    <pre><code>

    lbstatus <strong>-50</strong>    0   25   25

    lbstatus -25    0  <strong>-25</strong>   50

    lbstatus   0    0    0    <strong>0</strong>

    (repeat)

    </code></pre>

    <p>That is it schedules: a c d a c d a c d ...</p>

    <p>The following asymmetric configuration works as one would expect:</p>



    <table><tr><th>worker</th>

        <th class="data">a</th>

        <th class="data">b</th></tr>

<tr><th>lbfactor</th>

        <td class="data">70</td>

        <td class="data">30</td></tr>

<tr><th>lbstatus</th>

        <td class="data">-30</td>

        <td class="data">30</td></tr>

<tr><th>lbstatus</th>

        <td class="data">40</td>

        <td class="data">-40</td></tr>

<tr><th>lbstatus</th>

        <td class="data">10</td>

        <td class="data">-10</td></tr>

<tr><th>lbstatus</th>

        <td class="data">-20</td>

        <td class="data">20</td></tr>

<tr><th>lbstatus</th>

        <td class="data">-50</td>

        <td class="data">50</td></tr>

<tr><th>lbstatus</th>

        <td class="data">20</td>

        <td class="data">-20</td></tr>

<tr><th>lbstatus</th>

        <td class="data">-10</td>

        <td class="data">10</td></tr>

<tr><th>lbstatus</th>

        <td class="data">-40</td>

        <td class="data">40</td></tr>

<tr><th>lbstatus</th>

        <td class="data">30</td>

        <td class="data">-30</td></tr>

<tr><th>lbstatus</th>

        <td class="data">0</td>

        <td class="data">0</td></tr>

<tr><td class="data" colspan="3">(repeat)</td></tr>

</table>



    <p>That is after 10 schedules, the schedule repeats and 7 a are selected

    with 3 b interspersed.</p>

    <pre><code>

    worker     a    b

    lbfactor  70   30



    lbstatus <strong>-30</strong>   30

    lbstatus  40  <strong>-40</strong>

    lbstatus  <strong>10</strong>  -10

    lbstatus <strong>-20</strong>   20

    lbstatus <strong>-50</strong>   50

    lbstatus  20  <strong>-20</strong>

    lbstatus <strong>-10</strong>   10

    lbstatus <strong>-40</strong>   40

    lbstatus  30  <strong>-30</strong>

    lbasatus   <strong>0</strong>    0

    (repeat)

    </code></pre>



    <p>That is after 10 schedules, the schedule repeats and 7 <var>a</var>

    are selected with 3 <var>b</var> interspersed.</p>

</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>

<div class="section">

<h2><a name="enable" id="enable">Enabling Balancer Manager Support</a></h2>

docs/manual/mod/mod_proxy_balancer.xml

+39 −85
Original line number Diff line number Diff line
@@ -69,98 +69,52 @@ load balancing </description> 


    <p>If some workers are disabled, the others will

    still be scheduled correctly.</p>

    <example><pre>

for each worker in workers

    worker lbstatus += worker lbfactor

    total factor    += worker lbfactor

    if worker lbstatus > candidate lbstatus

       candidate = worker



candidate lbstatus -= total factor



    </pre></example>

    <p>If a balancer is configured as follows:</p>

    

    <table style="data">

    <tr><th>worker</th>

        <th>a</th>

        <th>b</th>

        <th>c</th>

        <th>d</th></tr>

    <tr><th>lbfactor</th>

        <td>25</td>

        <td>25</td>

        <td>25</td>

        <td>25</td></tr>

    <tr><th>lbstatus</th>

        <td>0</td>

        <td>0</td>

        <td>0</td>

        <td>0</td></tr>

    </table>

    <pre><code>

    worker     a    b    c    d

    lbfactor  25   25   25   25

    lbstatus   0    0    0    0

    </code></pre>



    <p>And <var>b</var> gets disabled, the following schedule is produced:</p>



    <table style="data">

    <tr><th>worker</th>

        <th>a</th>

        <th>b</th>

        <th>c</th>

        <th>d</th></tr>

    <tr><th>lbstatus</th>

        <td>-50</td>

        <td>0</td>

        <td>25</td>

        <td>25</td></tr>

    <tr><th>lbstatus</th>

        <td>-25</td>

        <td>0</td>

        <td>-25</td>

        <td>50</td></tr>

    <tr><th>lbstatus</th>

        <td>0</td>

        <td>0</td>

        <td>0</td>

        <td>0</td></tr>

    <tr><td colspan="5">(repeat)</td></tr>

    </table>



    <pre><code>

    lbstatus <strong>-50</strong>    0   25   25

    lbstatus -25    0  <strong>-25</strong>   50

    lbstatus   0    0    0    <strong>0</strong>

    (repeat)

    </code></pre>

    <p>That is it schedules: a c d a c d a c d ...</p>

    <p>The following asymmetric configuration works as one would expect:</p>



    <table style="data">

    <tr><th>worker</th>

        <th>a</th>

        <th>b</th></tr>

    <tr><th>lbfactor</th>

        <td>70</td>

        <td>30</td></tr>

    <tr><th>lbstatus</th>

        <td>-30</td>

        <td>30</td></tr>

    <tr><th>lbstatus</th>

        <td>40</td>

        <td>-40</td></tr>

    <tr><th>lbstatus</th>

        <td>10</td>

        <td>-10</td></tr>

    <tr><th>lbstatus</th>

        <td>-20</td>

        <td>20</td></tr>

    <tr><th>lbstatus</th>

        <td>-50</td>

        <td>50</td></tr>

    <tr><th>lbstatus</th>

        <td>20</td>

        <td>-20</td></tr>

    <tr><th>lbstatus</th>

        <td>-10</td>

        <td>10</td></tr>

    <tr><th>lbstatus</th>

        <td>-40</td>

        <td>40</td></tr>

    <tr><th>lbstatus</th>

        <td>30</td>

        <td>-30</td></tr>

    <tr><th>lbstatus</th>

        <td>0</td>

        <td>0</td></tr>

    <tr><td colspan="3">(repeat)</td></tr>

    </table>



    <p>That is after 10 schedules, the schedule repeats and 7 a are selected

    with 3 b interspersed.</p>

    <pre><code>

    worker     a    b

    lbfactor  70   30



    lbstatus <strong>-30</strong>   30

    lbstatus  40  <strong>-40</strong>

    lbstatus  <strong>10</strong>  -10

    lbstatus <strong>-20</strong>   20

    lbstatus <strong>-50</strong>   50

    lbstatus  20  <strong>-20</strong>

    lbstatus <strong>-10</strong>   10

    lbstatus <strong>-40</strong>   40

    lbstatus  30  <strong>-30</strong>

    lbasatus   <strong>0</strong>    0

    (repeat)

    </code></pre>



    <p>That is after 10 schedules, the schedule repeats and 7 <var>a</var>

    are selected with 3 <var>b</var> interspersed.</p>

</section>



<section id="enable">