Description

Search operations might fail if the query length exceeds the Solr request header size limit. The following message can be found in the logs:

Exception: System.Net.WebException
Message: The remote server returned an error: (414) URI Too Long.
Source: System
   at System.Net.HttpWebRequest.GetResponse()
   at HttpWebAdapters.Adapters.HttpWebRequestAdapter.GetResponse()
   at SolrNet.Impl.SolrConnection.GetResponse(IHttpWebRequest request)
   at SolrNet.Impl.SolrConnection.Get(String relativeUrl, IEnumerable`1 parameters)

or

Exception: System.Net.WebException
Message: The remote server returned an error: (431) Request Header Fields Too Large.
Source: System
   at System.Net.HttpWebRequest.GetResponse()
   at HttpWebAdapters.Adapters.HttpWebRequestAdapter.GetResponse()
   at SolrNet.Impl.SolrConnection.GetResponse(IHttpWebRequest request)
   at SolrNet.Impl.SolrConnection.Get(String relativeUrl, IEnumerable`1 parameters)

Solution

To resolve the issue, consider the following options:

• Review the code resulting in long queries. Sitecore recommends that you rewrite queries to shorten their length. Queries with a lot of clauses are executed slower and increase resource consumption.
  
  
• Increase the limit on the request header size at the Solr side. For example, when running Solr on Jetty, take the following steps:
  1. Open the <solr_root_folder>\server\etc\jetty.xml file.
  2. Change
     

     <set name="requestHeaderSize">
       <property name="solr.jetty.request.header.size" default="8192" />
     </set>

     to:

     <set name="requestHeaderSize">
       <property name="solr.jetty.request.header.size" default="16386" />
     </set>

  3. Save the changes.
  4. Restart Solr and Sitecore XP.
     
     
• For Sitecore XP 10.3 and later versions, set the following connection configuration used for Query operations by creating a configuration patch file in the \App_Config\Include\zzz folder:

  <?xml version="1.0" encoding="utf-8" ?>
  <configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:role="http://www.sitecore.net/xmlconfig/role/" xmlns:search="http://www.sitecore.net/xmlconfig/search/">
    <sitecore search:require="solr">
      <contentSearch>
        <indexConfigurations>
          <solrConnectionConfigurations>
            <solrConnectionConfiguration name="query">
              <timeout>0</timeout>
              <usePost>true</usePost>
            </solrConnectionConfiguration>
          </solrConnectionConfigurations>
        </indexConfigurations>
      </contentSearch>
    </sitecore>
  </configuration>

  For more information, see the article at https://doc.sitecore.com/xp/en/developers/103/platform-administration-and-architecture/specify-connection-timeout.html.
  
  
• For Sitecore XP 10.0–10.2, enable POST requests on Solr with the ContentSearch.Solr.SendPostRequests setting by creating a configuration patch file in the \App_Config\Include\zzz folder:

  <?xml version="1.0" encoding="utf-8" ?>
  <configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:role="http://www.sitecore.net/xmlconfig/role/" xmlns:search="http://www.sitecore.net/xmlconfig/search/">
    <sitecore search:require="solr">
      <settings>
        <setting name="ContentSearch.Solr.SendPostRequests" value="true"/>
      </settings>
    </sitecore>
  </configuration>