| HTML |
|---|
<div class="section" id="add-trigger"> <span id="index-0"></span><span id="id1"></span> <div class="line-block"> <div class="line">In the previous exercise we saw that the two tasks were running simultaneously.</div> <div class="line">We would like now to make sure that <strong>t2</strong> only runs once <strong>t1</strong> is complete.</div> <div class="line">For this we have to define a <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-trigger"><em class="xref std std-term">trigger</em></a></div> </div> <div class="highlight-python"><pre># Definition of the suite test. suite test edit ECF_INCLUDE "$HOME/course" edit ECF_HOME "$HOME/course" family f1 edit SLEEP 20 task t1 task t2 trigger t1 eq complete endfamily endsuite</pre> </div> <p>In python this would be:</p> <div class="highlight-python"><div class="highlight"><pre><span class="c">##!/usr/bin/env python2.5</span> <span class="kn">import</span> <span class="nn">os</span> <span class="kn">import</span> <span class="nn">ecflow</span> <span class="k">def</span> <span class="nf">create_family_f1</span><span class="p">():</span> <span class="n">f1</span> <span class="o">=</span> <span class="n">ecflow</span><span class="o">.</span><span class="n">Family</span><span class="p">(</span><span class="s">"f1"</span><span class="p">)</span> <span class="n">f1</span><span class="o">.</span><span class="n">add_variable</span><span class="p">(</span><span class="s">"SLEEP"</span><span class="p">,</span><span class="mi">20</span><span class="p">)</span> <span class="n">f1</span><span class="o">.</span><span class="n">add_task</span><span class="p">(</span><span class="s">"t1"</span><span class="p">)</span> <span class="n">t2</span> <span class="o">=</span> <span class="n">f1</span><span class="o">.</span><span class="n">add_task</span><span class="p">(</span><span class="s">"t2"</span><span class="p">)</span> <span class="n">t2</span><span class="o">.</span><span class="n">add_trigger</span><span class="p">(</span><span class="s">"t1 eq complete"</span><span class="p">)</span> <span class="k">return</span> <span class="n">f1</span> <span class="n">defs</span> <span class="o">=</span> <span class="n">ecflow</span><span class="o">.</span><span class="n">Defs</span><span class="p">(</span><span class="s">"test.def"</span><span class="p">)</span> <span class="n">suite</span> <span class="o">=</span> <span class="n">defs</span><span class="o">.</span><span class="n">add_suite</span><span class="p">(</span><span class="s">"test"</span><span class="p">)</span> <span class="n">suite</span><span class="o">.</span><span class="n">add_variable</span><span class="p">(</span><span class="s">"ECF_INCLUDE"</span><span class="p">,</span><span class="n">os</span><span class="o">.</span><span class="n">getenv</span><span class="p">(</span><span class="s">"HOME"</span><span class="p">)</span> <span class="o">+</span> <span class="s">"/course"</span><span class="p">)</span> <span class="n">suite</span><span class="o">.</span><span class="n">add_variable</span><span class="p">(</span><span class="s">"ECF_HOME "</span><span class="p">,</span><span class="n">os</span><span class="o">.</span><span class="n">getenv</span><span class="p">(</span><span class="s">"HOME"</span><span class="p">)</span> <span class="o">+</span> <span class="s">"/course"</span><span class="p">)</span> <span class="n">suite</span><span class="o">.</span><span class="n">add_family</span><span class="p">(</span> <span class="n">create_family_f1</span><span class="p">()</span> <span class="p">)</span> </pre></div> </div> <div class="line-block"> <div class="line">Triggers are used to declare <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-dependencies"><em class="xref std std-term">dependencies</em></a> between two tasks.</div> <div class="line">For instance, the second task might need data created by the first task.</div> </div> <div class="line-block"> <div class="line">When ecFlow tries to start a task, it evaluates the <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-trigger"><em class="xref std std-term">trigger</em></a> expression.</div> <div class="line">If the condition is correct, the task is started, otherwise the task</div> <div class="line">stays <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-queued"><em class="xref std std-term">queued</em></a>.</div> </div> <div class="line-block"> <div class="line">Triggers can be between tasks, or between families, or a mixture.</div> <div class="line">Remember the two rules:</div> </div> <ul class="simple"> <li>A family is <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-complete"><em class="xref std std-term">complete</em></a> when all its tasks are <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-complete"><em class="xref std std-term">complete</em></a>.</li> <li>A task will be started if its triggers and the triggers of all is parent families evaluate to true.</li> </ul> <div class="line-block"> <div class="line">A <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-node"><em class="xref std std-term">node</em></a> can only have one trigger expression, but very complex</div> <div class="line">expressions can be built (and keep in mind that the triggers of the</div> <div class="line">parent nodes are also implicit triggers).</div> </div> <div class="line-block"> <div class="line">Sometimes triggers are also used to prevent too many jobs from running</div> <div class="line">at the same time. In this case the use of a <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-limit"><em class="xref std std-term">limit</em></a> may be a better</div> <div class="line">solution (we will cover limits later on in the <a class="reference internal" href="/wiki/display/ECFLOW/Limits#limits"><em>Limits</em></a> section).</div> </div> <div class="line-block"> <div class="line">Triggers can be very complex, and ecFlow supports all kinds of conditions</div> <div class="line">(not, and, or, ...)</div> </div> <p>What to do:</p> <ol class="arabic simple"> <li>Edit the <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-suite-definition"><em class="xref std std-term">suite definition</em></a> file to add the <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-trigger"><em class="xref std std-term">trigger</em></a>.</li> <li>Play the definition again.</li> <li>Observe the tasks in <a class="reference internal" href="/wiki/display/ECFLOW/Glossary#term-ecflowview"><em class="xref std std-term">ecFlowview</em></a>.</li> <li>See the triggers by selecting <strong>t1</strong> or <strong>t2</strong> and clicking on the <img alt="triggers" src="../../../_images/triggers.jpg" /> icon.</li> <li>See the trigger relation by clicking on the arrow.</li> <li>See the triggers in the tree, using the Show menu.</li> <li>Search any reference to <strong>t1</strong> by using the <img alt="search" src="../../../_images/search.jpg" /> icon</li> </ol> </div> |
Page History
Overview
Community Forums
Content Tools