It’s swimming against the tide to use HTTP instead of HTTPS with Sitecore and Solr, but there were a series of circumstances that had us reviewing the SSL default and evaluating other options. I had to go to Sitecore support for clarification on setting up Solr over HTTP instead of HTTPS (now that HTTPS is the default in the Sitecore 9 space). There wasn’t succinct documentation from Sitecore, so let me share the findings here in case it helps others . . .
For the standard Sitecore CM and CD roles, one can update the ContentSearch.Solr.ServiceBaseAddress URL — just use http instead of https.
For the Sitecore xConnect role, one needs to change the following configuration:
1) For the Collection instance, update the App_data\config\sitecore\CollectionSearch\sc.Xdb.Collection.IndexReader.SOLR.xml file:
<Options>
<ConnectionStringName>solrCore</ConnectionStringName>
<RequireHttps>false</RequireHttps>
</Options>
2) For the xConnect Indexer instance, update the App_data\jobs\continuous\IndexWorker\App_data\Config\Sitecore\CollectionSearch\sc.Xdb.Collection.IndexReader.SOLR.xml file:
<Options>
<ConnectionStringName>solrCore</ConnectionStringName>
<RequireHttps>false</RequireHttps>
</Options>
3) Also for the xConnect Indexer instance, update the App_data\jobs\continuous\IndexWorker\App_data\Config\Sitecore\SearchIndexer\sc.Xdb.Collection.IndexWriter.SOLR.xml file:
<Options>
<ConnectionStringName>solrCore</ConnectionStringName>
<RequireHttps>false</RequireHttps>
<Encoding>utf-8</Encoding>
</Options>
…
<Options>
<ConnectionStringName>solrCore</ConnectionStringName>
<RequireHttps>false</RequireHttps>
<MaximumUpdateBatchSize>1000</MaximumUpdateBatchSize>
<MaximumDeleteBatchSize>1000</MaximumDeleteBatchSize>
<MaximumCommitMilliseconds>1000</MaximumCommitMilliseconds>
<ParallelizationDegree>4</ParallelizationDegree>
<MaximumRetryDelayMilliseconds>5000</MaximumRetryDelayMilliseconds>
<RetryCount>5</RetryCount>
<Encoding>utf-8</Encoding>
</Options>
