Merge pull request #4599 from vespa-engine/bjormel/application-variant

Document the new `application` dimension

Author: bjormel

en/operations/deployment-variants.html

@@ -1,6 +1,6 @@
 ---
 # Copyright Vespa.ai. All rights reserved.
-title: "Instance, region, cloud and environment variants"
+title: "Application, instance, region, cloud and environment variants"
 applies_to: cloud
 redirect_from:
 - en/reference/deployment-variants.html
@@ -9,7 +9,8 @@
 <p>
   Sometimes it is useful to create configuration that varies depending on properties of the deployment,
   for example to set region specific endpoints of services used by <a href="/en/applications/searchers.html">Searchers</a>,
-  or use smaller clusters for a "beta" instance.
+  use smaller clusters for a "beta" instance, or vary configuration when the same application package is shared across
+  multiple applications.
 </p>
 <p>
   This is supported both for <a href="#services.xml-variants">services.xml</a> and
@@ -21,14 +22,14 @@
 <h2 id="services.xml-variants">services.xml variants</h2>
 <p>
   <a href="../reference/applications/services/services.html">services.xml</a> files support different configuration settings
-  for different <em>tags</em>, <em>instances</em>, <em>environments</em>, <em>clouds</em> and <em>regions</em>.
+  for different <em>tags</em>, <em>applications</em>, <em>instances</em>, <em>environments</em>, <em>clouds</em> and <em>regions</em>.
   To use this, import the <em>deploy</em> namespace:
 </p>
 <pre>{% highlight xml %}
 <services version="1.0" xmlns:deploy="vespa">
 {% endhighlight %}</pre>
 <p>
-  Deploy directives are used to specify with which tags, and in which instance, environment,
+  Deploy directives are used to specify with which tags, and in which application, instance, environment,
   cloud and/or <a href="https://cloud.vespa.ai/en/reference/zones">region</a> an XML element should be included:
 </p>
 <pre>{% highlight xml %}
@@ -56,6 +57,11 @@ <h2 id="services.xml-variants">services.xml variants</h2>
            count="4">
         <resources vcpu="16.0" memory="256Gb" disk="3750Gb"/>
     </nodes>
+    <nodes deploy:application="my-app"
+           deploy:environment="prod"
+           count="30">
+        <resources vcpu="16.0" memory="128Gb" disk="3750Gb"/>
+    </nodes>
     <nodes deploy:tags="myTag1 myTag2" count="8" />
 </content>
 {% endhighlight %}</pre>
@@ -104,7 +110,7 @@ <h2 id="services.xml-variants">services.xml variants</h2>
 
 
 <h3 id="advanced">Specifying multiple targets</h3>
-<p>More than one tag, instance, region or environment can be specified in the attribute, separated by space.</p>
+<p>More than one tag, application, instance, region or environment can be specified in the attribute, separated by space.</p>
 <p>
   Note that <code>tags</code> by default only apply in production instances,
   and are matched whenever the tags of the element and the tags of the instance intersect.
@@ -137,40 +143,40 @@ <h3 id="advanced">Specifying multiple targets</h3>
 <h2 id="query-profile-variants">Query profile variants</h2>
 <p>
   <a href="/en/querying/query-profiles.html">Query profiles</a> support different configuration settings
-  for different <em>instances</em>, <em>environments</em> and <em>regions</em> through
+  for different <em>applications</em>, <em>instances</em>, <em>environments</em> and <em>regions</em> through
   <a href="/en/querying/query-profiles.html#query-profile-variants">query profile variants</a>.
   This allows you to set different query parameters for a query type depending on these deployment attributes.
 </p>
 <p>
   To use this feature, create a regular query profile variant with any of
-  <code>instance</code>, <code>environment</code> and <code>region</code> as dimension names and
+  <code>application</code>, <code>instance</code>, <code>environment</code> and <code>region</code> as dimension names and
   let your query profile vary by that. For example:
 </p>
 <pre>{% highlight xml %}
 <query-profile id="default">
 
-    <dimensions>instance, environment, region</dimensions>
+    <dimensions>application, instance, environment, region</dimensions>
 
     <field name="a">My default value</field>
 
     <!-- Value for (any deployment of) the beta instance -->
-    <query-profile for="beta">
+    <query-profile for="*, beta">
         <field name="a">My beta value</field>
     </query-profile>
 
     <!-- Value for (any) dev deployment -->
-    <query-profile for="*, dev">
+    <query-profile for="*, *, dev">
         <field name="a">My dev value</field>
     </query-profile>
 
     <!-- Value for the default instance in prod -->
-    <query-profile for="default, prod">
+    <query-profile for="*, default, prod">
         <field name="a">My main instance prod value</field>
     </query-profile>
 
 </query-profile>
 {% endhighlight %}</pre>
 <p>You can pick and combine these dimensions in any way you want with other dimensions sent as query parameters, e.g:</p>
 <pre>{% highlight xml %}
-    <dimensions>device, instance, usecase</dimensions>
+    <dimensions>device, application, instance, usecase</dimensions>
 {% endhighlight %}</pre>