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    <title>Class ClusterNodeAttributeAffinityBackupFilter
   | Apache Ignite.NET </title>
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            <article class="content wrap" id="_content" data-uid="Apache.Ignite.Core.Cache.Affinity.Rendezvous.ClusterNodeAttributeAffinityBackupFilter">
  
  
  <h1 id="Apache_Ignite_Core_Cache_Affinity_Rendezvous_ClusterNodeAttributeAffinityBackupFilter" data-uid="Apache.Ignite.Core.Cache.Affinity.Rendezvous.ClusterNodeAttributeAffinityBackupFilter" class="text-break">Class ClusterNodeAttributeAffinityBackupFilter
  </h1>
  <div class="markdown level0 summary"><p>Attribute-based affinity backup filter, see <a class="xref" href="Apache.Ignite.Core.Cluster.IBaselineNode.html#Apache_Ignite_Core_Cluster_IBaselineNode_Attributes">Attributes</a>,
<a class="xref" href="Apache.Ignite.Core.Cache.Affinity.Rendezvous.RendezvousAffinityFunction.html#Apache_Ignite_Core_Cache_Affinity_Rendezvous_RendezvousAffinityFunction_AffinityBackupFilter">AffinityBackupFilter</a>.
<p>
This filter can be used to ensure that, for a given partition, primary and backup nodes are selected from
different racks in a datacenter, or from different availability zones in a cloud environment, so that
a single hardware failure does not cause data loss.
<p>
This implementation will discard backups rather than place multiple on the same set of nodes. This avoids
trying to cram more data onto remaining nodes  when some have failed.
<p>
This class is constructed with a set of node attribute names, and a candidate node will be rejected if
<em>any</em> of the previously selected nodes for a partition have identical values for <em>all</em> of those attributes
on the candidate node. Another way to understand this is the set of attribute values defines the key of a
group into which a node is placed, and the primaries and backups for a partition cannot share nodes
in the same group. A null attribute is treated as a distinct value, so two nodes with a null attribute will
be treated as having the same value.
<p>
For example, let&apos;s say Ignite cluster of 12 nodes is deployed into 3 racks - r1, r2, r3. Ignite nodes
have &quot;SITE&quot; attributes set accordingly to &quot;r1&quot;, &quot;r2&quot;, &quot;r3&quot;. For a cache with 1 backup
(<a class="xref" href="Apache.Ignite.Core.Cache.Configuration.CacheConfiguration.html#Apache_Ignite_Core_Cache_Configuration_CacheConfiguration_Backups">Backups</a> set to <code>1</code>), every partition is assigned to 2 nodes.
When the primary node has &quot;SITE&quot; attribute set to &quot;r1&quot;, all other nodes with &quot;SITE&quot;=&quot;r1&quot; are excluded
by this filter when selecting the backup node.</p>
</div>
  <div class="markdown level0 conceptual"></div>
  <div class="inheritance">
    <h5>Inheritance</h5>
    <div class="level0"><span class="xref">System.Object</span></div>
    <div class="level1"><span class="xref">ClusterNodeAttributeAffinityBackupFilter</span></div>
  </div>
  <div classs="implements">
    <h5>Implements</h5>
    <div><a class="xref" href="Apache.Ignite.Core.Cache.Affinity.IAffinityBackupFilter.html">IAffinityBackupFilter</a></div>
  </div>
  <div class="inheritedMembers">
    <h5>Inherited Members</h5>
    <div>
      <span class="xref">System.Object.ToString()</span>
    </div>
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      <span class="xref">System.Object.Equals(System.Object)</span>
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      <span class="xref">System.Object.Equals(System.Object, System.Object)</span>
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      <span class="xref">System.Object.ReferenceEquals(System.Object, System.Object)</span>
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    </div>
    <div>
      <span class="xref">System.Object.GetType()</span>
    </div>
    <div>
      <span class="xref">System.Object.MemberwiseClone()</span>
    </div>
  </div>
  <h6><strong>Namespace</strong>: <a class="xref" href="Apache.Ignite.Core.Cache.Affinity.Rendezvous.html">Apache.Ignite.Core.Cache.Affinity.Rendezvous</a></h6>
  <h6><strong>Assembly</strong>: Apache.Ignite.Core.dll</h6>
  <h5 id="Apache_Ignite_Core_Cache_Affinity_Rendezvous_ClusterNodeAttributeAffinityBackupFilter_syntax">Syntax</h5>
  <div class="codewrapper">
    <pre><code class="lang-csharp hljs">public sealed class ClusterNodeAttributeAffinityBackupFilter : IAffinityBackupFilter</code></pre>
  </div>
  <h3 id="properties">Properties
  </h3>
  <a id="Apache_Ignite_Core_Cache_Affinity_Rendezvous_ClusterNodeAttributeAffinityBackupFilter_AttributeNames_" data-uid="Apache.Ignite.Core.Cache.Affinity.Rendezvous.ClusterNodeAttributeAffinityBackupFilter.AttributeNames*"></a>
  <h4 id="Apache_Ignite_Core_Cache_Affinity_Rendezvous_ClusterNodeAttributeAffinityBackupFilter_AttributeNames" data-uid="Apache.Ignite.Core.Cache.Affinity.Rendezvous.ClusterNodeAttributeAffinityBackupFilter.AttributeNames">AttributeNames</h4>
  <div class="markdown level1 summary"><p>Gets or sets the attribute names.</p>
</div>
  <div class="markdown level1 conceptual"></div>
  <h5 class="decalaration">Declaration</h5>
  <div class="codewrapper">
    <pre><code class="lang-csharp hljs">public ICollection&lt;string&gt; AttributeNames { get; set; }</code></pre>
  </div>
  <h5 class="propertyValue">Property Value</h5>
  <table class="table table-bordered table-striped table-condensed">
    <thead>
      <tr>
        <th>Type</th>
        <th>Description</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td><span class="xref">System.Collections.Generic.ICollection</span>&lt;<span class="xref">System.String</span>&gt;</td>
        <td></td>
      </tr>
    </tbody>
  </table>
  <h3 id="implements">Implements</h3>
  <div>
      <a class="xref" href="Apache.Ignite.Core.Cache.Affinity.IAffinityBackupFilter.html">IAffinityBackupFilter</a>
  </div>
</article>
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