This table presents the compatibility of different Sitecore CMS/XP versions with different Solr versions. Solr CMS 7.0 – XP 8.0 XP 8.1 XP 8.2 XP 9.0 1.1 – 4.0 – – – – 4.1 ✓ * * – 4.2 – 4.7 * * * – 4.8 – 4.9 *[1] * * – 4.10 *[1] ✓ * – 5.0 *[1] * * – 5.1 *[1] * ✓ – 5.2 – 5.4 *[1] * * – 5.5 –[3] –[3] –[3] – 5.5.1, 6.0 – 6.1 *[1][2] *[2] *[2] – 6.6.1 – – – ✓[4] Legend: ✓ officially tested, recommended * not officially tested, but expected to work – no compatibility information or does not work Note: Solr Cloud setups are under experimental support from Sitecore XP 8.2, so you can experience some support issues. Sitecore Support will help with troubleshooting, although there is no guarantee that a fix will be available. In earlier versions of Sitecore CMS/XP, only standalone Solr setups are supported. Sitecore was not tested for compatibility with the Solr Index replication feature.
[1] Changes in the default schema.xml file shipped with Solr 4.8 and later can cause the following issues: Sitecore cannot be initialized due to the following error: [NullReferenceException: Object reference not set to an instance of an object.] SolrNet.Schema.SolrSchemaParser.Parse(XDocument solrSchemaXml) +425 SolrNet.Impl.SolrBasicServer`1.GetSchema() +207 Sitecore.ContentSearch.SolrProvider.SolrSearchIndex.Initialize() +1125 Sitecore.ContentSearch.SolrProvider.SolrContentSearchManager.Initialize() +168 Sitecore.ContentSearch.SolrProvider.CastleWindsorIntegration.WindsorSolrStartUp.Initialize() +757 The Build Solr Schema wizard successfully completes building the schema, but the resulting schema.xml file lacks a Sitecore-specific configuration. To resolve the issue, apply the corresponding solution 1 described in the following Solution section. [2] Starting from Solr 6, the default Config Sets are distributed without the schema.xml file. To resolve the issue, apply the corresponding solution 2 described in the following Solution section. [3] Known issues for Solr 5.5 (https://issues.apache.org/jira/browse/SOLR-8793) result in the following Sitecore error: WARN Unable to connect to Solr: [http://{hostname}:{port}/solr], the [SolrNet.Exceptions.SolrConnectionException] was caught. Exception: SolrNet.Exceptions.SolrConnectionException Message: Error handling 'status' actionorg.apache.solr.common.SolrException: Error handling 'status' action To resolve the issue, upgrade Solr to 5.5.1 or a later version. [4] Solr server can try to initialize a Solr core twice, resulting in the following error: org.apache.solr.common.SolrException: Unable to create core [core_name] ... Caused by: org.apache.lucene.store.LockObtainFailedException: Lock held by this virtual machine: C:\solr-6.6.1\server\solr\core_name\data\index\write.lock The error is caused by a Solr bug: SOLR-11297 The issue does not affect Sitecore functionality and can be ignored. To resolve the issue, upgrade Solr to 6.6.2.
Note: Solution [2] should be implemented before Solution [1] if both of them apply to your specific SXP and Solr version combination. To resolve the issue: Make the following changes in the default schema.xml file distributed with Solr: Enclose all <field> and <dynamicField> elements in the <fields> tag. Enclose all <fieldType> elements in the <types> tag. To add the Sitecore-specific configuration, pass the modified schema.xml file to the Build Solr Schema wizard. Put the resulting file in the configuration folder of the Solr core. Find the following dynamic field definition in the schema.xml file: <dynamicField name="*_pi" type="pint" indexed="true" stored="true" /> Change the mapping type from "pint" to "tint".<dynamicField name="*_pi" type="tint" indexed="true" stored="true" /> Reload the core to apply the schema changes. Restart the application pool of the website to initialize the Sitecore indexes using the updated schema.xml file.
To resolve the issue: Create a schema.xml file by duplicating and renaming the managed-schema file. Switch to the ClassicIndexSchemaFactory setting by adding the following line to the SolrConfig.xml file: <schemaFactory class="ClassicIndexSchemaFactory" /> If the SolrConfig.xml file contains the following UpdateRequestProcessorChain <updateRequestProcessorChain name="add-unknown-fields-to-the-schema"> then find and comment out its AddSchemaFieldsUpdateProcessorFactory processor.