diff --git a/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/DefaultExceptionResolver.java b/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/DefaultExceptionResolver.java
index 9a7680dbaa..d5ac11cb9f 100644
--- a/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/DefaultExceptionResolver.java
+++ b/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/DefaultExceptionResolver.java
@@ -41,7 +41,11 @@ public class DefaultExceptionResolver implements ExceptionResolver<Exception>
     @Override
     public ErrorResponse resolveException(Exception ex)
     {
-        return new ErrorResponse(DEFAULT_MESSAGE_ID, HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex.getLocalizedMessage(), ex.getStackTrace(), null);
+        return new ErrorResponse(DEFAULT_MESSAGE_ID,
+                HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
+                ex.getLocalizedMessage(),
+                ex.getStackTrace(),
+                null);
     }
 
 }
diff --git a/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/QueryParserExceptionResolver.java b/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/QueryParserExceptionResolver.java
new file mode 100644
index 0000000000..2e6a89bb7b
--- /dev/null
+++ b/remote-api/src/main/java/org/alfresco/rest/framework/core/exceptions/QueryParserExceptionResolver.java
@@ -0,0 +1,48 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2021 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software. 
+ * If the software was purchased under a paid Alfresco license, the terms of 
+ * the paid license agreement will prevail.  Otherwise, the software is 
+ * provided under the following open source license terms:
+ * 
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package org.alfresco.rest.framework.core.exceptions;
+
+import org.alfresco.repo.search.QueryParserException;
+
+/**
+ * QueryParserException is related with search requests to Search Services.
+ */
+public class QueryParserExceptionResolver implements ExceptionResolver<QueryParserException>
+{
+
+    @Override
+    public ErrorResponse resolveException(QueryParserException ex)
+    {
+        return new ErrorResponse(
+            DefaultExceptionResolver.DEFAULT_MESSAGE_ID,
+            // Mapping the original HTTP Status code returned by Search Services
+            ex.getHttpStatusCode(),
+            ex.getLocalizedMessage(),
+            ex.getStackTrace(),
+            null);
+    }
+
+}
diff --git a/remote-api/src/main/java/org/alfresco/rest/framework/tools/ApiAssistant.java b/remote-api/src/main/java/org/alfresco/rest/framework/tools/ApiAssistant.java
index 4d2b137113..30adda5961 100644
--- a/remote-api/src/main/java/org/alfresco/rest/framework/tools/ApiAssistant.java
+++ b/remote-api/src/main/java/org/alfresco/rest/framework/tools/ApiAssistant.java
@@ -26,10 +26,12 @@
 package org.alfresco.rest.framework.tools;
 
 import org.alfresco.metrics.rest.RestMetricsReporter;
+import org.alfresco.repo.search.QueryParserException;
 import org.alfresco.rest.framework.Api;
 import org.alfresco.rest.framework.core.exceptions.DefaultExceptionResolver;
 import org.alfresco.rest.framework.core.exceptions.ErrorResponse;
 import org.alfresco.rest.framework.core.exceptions.ExceptionResolver;
+import org.alfresco.rest.framework.core.exceptions.QueryParserExceptionResolver;
 import org.alfresco.rest.framework.jacksonextensions.JacksonHelper;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -48,6 +50,7 @@ public class ApiAssistant {
 
     private ExceptionResolver<Exception> defaultResolver = new DefaultExceptionResolver();
     private ExceptionResolver<WebScriptException> webScriptExceptionResolver;
+    private ExceptionResolver<QueryParserException> queryParserExceptionResolver;
     private ExceptionResolver<Exception> resolver;
     private JacksonHelper jsonHelper;
     private RestMetricsReporter restMetricsReporter;
@@ -77,6 +80,10 @@ public class ApiAssistant {
         {
             error = webScriptExceptionResolver.resolveException((WebScriptException) ex);
         }
+        else if (ex instanceof QueryParserException)
+        {
+            error = queryParserExceptionResolver.resolveException((QueryParserException) ex);
+        }
         else
         {
             error = resolver.resolveException(ex);
@@ -100,6 +107,11 @@ public class ApiAssistant {
         this.webScriptExceptionResolver = webScriptExceptionResolver;
     }
 
+    public void setQueryParserExceptionResolver(ExceptionResolver<QueryParserException> queryParserExceptionResolver)
+    {
+        this.queryParserExceptionResolver = queryParserExceptionResolver;
+    }
+
     public void setResolver(ExceptionResolver<Exception> resolver) {
         this.resolver = resolver;
     }
diff --git a/remote-api/src/main/resources/alfresco/public-rest-context.xml b/remote-api/src/main/resources/alfresco/public-rest-context.xml
index 7d4e4fcfa8..8c965e2a36 100644
--- a/remote-api/src/main/resources/alfresco/public-rest-context.xml
+++ b/remote-api/src/main/resources/alfresco/public-rest-context.xml
@@ -134,6 +134,8 @@
     </bean>
     <bean id="webScriptExceptionResolver" class="org.alfresco.rest.framework.core.exceptions.WebScriptExceptionResolver">
     </bean>
+    <bean id="queryParserExceptionResolver" class="org.alfresco.rest.framework.core.exceptions.QueryParserExceptionResolver">
+    </bean>
     <bean id="simpleMappingExceptionResolverParent" abstract="true" class="org.alfresco.rest.framework.core.exceptions.SimpleMappingExceptionResolver">
         <property name="exceptionMappings">
             <map>
@@ -182,6 +184,7 @@
         <property name="resolver" ref="simpleMappingExceptionResolver" />
         <property name="webScriptExceptionResolver" ref="webScriptExceptionResolver" />
         <property name="restMetricsReporter" ref="restMetricsReporter"/>
+        <property name="queryParserExceptionResolver" ref="queryParserExceptionResolver" />
     </bean>
     
 	<!-- Using annotation-config=false means AutowiredAnnotationBeanPostProcessor 
diff --git a/remote-api/src/test/java/org/alfresco/rest/framework/tests/core/ExceptionResolverTests.java b/remote-api/src/test/java/org/alfresco/rest/framework/tests/core/ExceptionResolverTests.java
index 0aedab08ac..874a0c6f48 100644
--- a/remote-api/src/test/java/org/alfresco/rest/framework/tests/core/ExceptionResolverTests.java
+++ b/remote-api/src/test/java/org/alfresco/rest/framework/tests/core/ExceptionResolverTests.java
@@ -23,45 +23,46 @@
  * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
  * #L%
  */
-package org.alfresco.rest.framework.tests.core;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-
-import org.alfresco.repo.forms.FormNotFoundException;
+package org.alfresco.rest.framework.tests.core;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import org.alfresco.repo.forms.FormNotFoundException;
 import org.alfresco.repo.node.integrity.IntegrityException;
-import org.alfresco.rest.framework.core.exceptions.ApiException;
-import org.alfresco.rest.framework.core.exceptions.ConstraintViolatedException;
-import org.alfresco.rest.framework.core.exceptions.DeletedResourceException;
-import org.alfresco.rest.framework.core.exceptions.EntityNotFoundException;
-import org.alfresco.rest.framework.core.exceptions.ErrorResponse;
+import org.alfresco.repo.search.QueryParserException;
+import org.alfresco.rest.framework.core.exceptions.ApiException;
+import org.alfresco.rest.framework.core.exceptions.ConstraintViolatedException;
+import org.alfresco.rest.framework.core.exceptions.DeletedResourceException;
+import org.alfresco.rest.framework.core.exceptions.EntityNotFoundException;
+import org.alfresco.rest.framework.core.exceptions.ErrorResponse;
 import org.alfresco.rest.framework.core.exceptions.InsufficientStorageException;
-import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
-import org.alfresco.rest.framework.core.exceptions.NotFoundException;
-import org.alfresco.rest.framework.core.exceptions.PermissionDeniedException;
-import org.alfresco.rest.framework.core.exceptions.RelationshipResourceNotFoundException;
-import org.alfresco.rest.framework.core.exceptions.StaleEntityException;
-import org.alfresco.rest.framework.core.exceptions.UnsupportedResourceOperationException;
-import org.alfresco.rest.framework.resource.parameters.where.InvalidQueryException;
+import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
+import org.alfresco.rest.framework.core.exceptions.NotFoundException;
+import org.alfresco.rest.framework.core.exceptions.PermissionDeniedException;
+import org.alfresco.rest.framework.core.exceptions.RelationshipResourceNotFoundException;
+import org.alfresco.rest.framework.core.exceptions.StaleEntityException;
+import org.alfresco.rest.framework.core.exceptions.UnsupportedResourceOperationException;
+import org.alfresco.rest.framework.resource.parameters.where.InvalidQueryException;
 import org.alfresco.rest.framework.tools.ApiAssistant;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.extensions.webscripts.WebScriptException;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.extensions.webscripts.WebScriptException;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
 import javax.servlet.http.HttpServletResponse;
 
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(locations = { "classpath:test-rest-context.xml" })
-public class ExceptionResolverTests
-{
-    @Autowired
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(locations = { "classpath:test-rest-context.xml" })
+public class ExceptionResolverTests
+{
+    @Autowired
     ApiAssistant assistant;
 
-    @Test
+    @Test
     public void testWebscriptException()
     {
         ErrorResponse response = assistant.resolveException(new WebScriptException(null));
@@ -75,43 +76,43 @@ public class ExceptionResolverTests
 
     //04180006 Authentication failed for Web Script org/alfresco/api/ResourceWebScript.get
     @Test
-    public void testMatchException()
-    {
+    public void testMatchException()
+    {
         ErrorResponse response = assistant.resolveException(new ApiException(null));
-        assertNotNull(response);
-        assertEquals(500, response.getStatusCode());  //default to INTERNAL_SERVER_ERROR
-       
+        assertNotNull(response);
+        assertEquals(500, response.getStatusCode());  //default to INTERNAL_SERVER_ERROR
+       
         response = assistant.resolveException(new InvalidArgumentException(null));
-        assertEquals(400, response.getStatusCode());  //default to STATUS_BAD_REQUEST
-
-        response = assistant.resolveException(new InvalidQueryException(null));
-        assertEquals(400, response.getStatusCode());  //default to STATUS_BAD_REQUEST
-        
-        response = assistant.resolveException(new NotFoundException(null));
-        assertEquals(404, response.getStatusCode());  //default to STATUS_NOT_FOUND
-        
-        response = assistant.resolveException(new EntityNotFoundException(null));
-        assertEquals(404, response.getStatusCode());  //default to STATUS_NOT_FOUND
-
-        response = assistant.resolveException(new RelationshipResourceNotFoundException(null, null));
-        assertEquals(404, response.getStatusCode());  //default to STATUS_NOT_FOUND
-
-        response = assistant.resolveException(new PermissionDeniedException(null));
-        assertEquals(403, response.getStatusCode());  //default to STATUS_FORBIDDEN
-
-        response = assistant.resolveException(new UnsupportedResourceOperationException(null));
-        assertEquals(405, response.getStatusCode());  //default to STATUS_METHOD_NOT_ALLOWED
-
-        response = assistant.resolveException(new DeletedResourceException(null));
-        assertEquals(405, response.getStatusCode());  //default to STATUS_METHOD_NOT_ALLOWED
-        
-        response = assistant.resolveException(new ConstraintViolatedException(null));
-        assertEquals(409, response.getStatusCode());  //default to STATUS_CONFLICT    
-        
-        response = assistant.resolveException(new StaleEntityException(null));
-        assertEquals(409, response.getStatusCode());  //default to STATUS_CONFLICT    
+        assertEquals(400, response.getStatusCode());  //default to STATUS_BAD_REQUEST
 
-        //Try a random exception
+        response = assistant.resolveException(new InvalidQueryException(null));
+        assertEquals(400, response.getStatusCode());  //default to STATUS_BAD_REQUEST
+        
+        response = assistant.resolveException(new NotFoundException(null));
+        assertEquals(404, response.getStatusCode());  //default to STATUS_NOT_FOUND
+        
+        response = assistant.resolveException(new EntityNotFoundException(null));
+        assertEquals(404, response.getStatusCode());  //default to STATUS_NOT_FOUND
+
+        response = assistant.resolveException(new RelationshipResourceNotFoundException(null, null));
+        assertEquals(404, response.getStatusCode());  //default to STATUS_NOT_FOUND
+
+        response = assistant.resolveException(new PermissionDeniedException(null));
+        assertEquals(403, response.getStatusCode());  //default to STATUS_FORBIDDEN
+
+        response = assistant.resolveException(new UnsupportedResourceOperationException(null));
+        assertEquals(405, response.getStatusCode());  //default to STATUS_METHOD_NOT_ALLOWED
+
+        response = assistant.resolveException(new DeletedResourceException(null));
+        assertEquals(405, response.getStatusCode());  //default to STATUS_METHOD_NOT_ALLOWED
+        
+        response = assistant.resolveException(new ConstraintViolatedException(null));
+        assertEquals(409, response.getStatusCode());  //default to STATUS_CONFLICT    
+        
+        response = assistant.resolveException(new StaleEntityException(null));
+        assertEquals(409, response.getStatusCode());  //default to STATUS_CONFLICT    
+
+        //Try a random exception
         response = assistant.resolveException(new FormNotFoundException(null));
         assertEquals(500, response.getStatusCode());  //default to INTERNAL_SERVER_ERROR
 
@@ -120,6 +121,15 @@ public class ExceptionResolverTests
 
         response = assistant.resolveException(new IntegrityException(null));
         assertEquals(422, response.getStatusCode());
-        
-    }
-}
+        
+    }
+
+    /** Check that the status code from SS is passed back to the caller. */
+    @Test
+    public void testQueryParserException()
+    {
+        ErrorResponse response = assistant.resolveException(new QueryParserException("Endpoint not found", 404));
+        assertNotNull(response);
+        assertEquals("Expected status code to be passed through from query parser.", 404, response.getStatusCode());
+    }
+}
diff --git a/remote-api/src/test/resources/test-rest-context.xml b/remote-api/src/test/resources/test-rest-context.xml
index 00b8f1b499..ce960a71e5 100644
--- a/remote-api/src/test/resources/test-rest-context.xml
+++ b/remote-api/src/test/resources/test-rest-context.xml
@@ -33,10 +33,12 @@
     </bean>
     <bean id="webScriptExceptionResolver" class="org.alfresco.rest.framework.core.exceptions.WebScriptExceptionResolver">
     </bean>
+    <bean id="queryParserExceptionResolver" class="org.alfresco.rest.framework.core.exceptions.QueryParserExceptionResolver" />
     <bean id="apiAssistant" class="org.alfresco.rest.framework.tools.ApiAssistant">
         <property name="jsonHelper" ref="jsonHelper" />
         <property name="resolver" ref="simpleMappingExceptionResolver" />
         <property name="webScriptExceptionResolver" ref="webScriptExceptionResolver" />
+        <property name="queryParserExceptionResolver" ref="queryParserExceptionResolver" />
     </bean>
     <bean id="simpleMappingExceptionResolver" class="org.alfresco.rest.framework.core.exceptions.SimpleMappingExceptionResolver">
        <property name="exceptionMappings">
diff --git a/repository/src/main/java/org/alfresco/repo/search/QueryParserException.java b/repository/src/main/java/org/alfresco/repo/search/QueryParserException.java
index 0078cd2836..f7b0a8d6f1 100644
--- a/repository/src/main/java/org/alfresco/repo/search/QueryParserException.java
+++ b/repository/src/main/java/org/alfresco/repo/search/QueryParserException.java
@@ -26,6 +26,9 @@
 package org.alfresco.repo.search;
 
 import org.alfresco.error.AlfrescoRuntimeException;
+import org.apache.http.HttpStatus;
+
+import java.util.List;
 
 /**
  * @author Andy
@@ -33,11 +36,10 @@ import org.alfresco.error.AlfrescoRuntimeException;
  */
 public class QueryParserException extends AlfrescoRuntimeException
 {
-
-    /**
-     *
-     */
+    /** Serial version UUID. */
     private static final long serialVersionUID = 4886993838297301968L;
+    /** Http Status Code that should be returned by Remote API. */
+    private int httpStatusCode;
 
     /**
      * @param msgId
@@ -45,7 +47,6 @@ public class QueryParserException extends AlfrescoRuntimeException
     public QueryParserException(String msgId)
     {
         super(msgId);
-        // TODO Auto-generated constructor stub
     }
 
     /**
@@ -55,7 +56,6 @@ public class QueryParserException extends AlfrescoRuntimeException
     public QueryParserException(String msgId, Object[] msgParams)
     {
         super(msgId, msgParams);
-        // TODO Auto-generated constructor stub
     }
 
     /**
@@ -65,7 +65,6 @@ public class QueryParserException extends AlfrescoRuntimeException
     public QueryParserException(String msgId, Throwable cause)
     {
         super(msgId, cause);
-        // TODO Auto-generated constructor stub
     }
 
     /**
@@ -76,7 +75,22 @@ public class QueryParserException extends AlfrescoRuntimeException
     public QueryParserException(String msgId, Object[] msgParams, Throwable cause)
     {
         super(msgId, msgParams, cause);
-        // TODO Auto-generated constructor stub
     }
 
+    /**
+     * Constructor for exception that allows setting an HTTP status code.
+     *
+     * @param msgId Message for the exception
+     * @param httpStatusCode Status code to return for exception
+     */
+    public QueryParserException(String msgId, int httpStatusCode)
+    {
+        super(msgId);
+        this.httpStatusCode = httpStatusCode;
+    }
+
+    public int getHttpStatusCode()
+    {
+        return httpStatusCode;
+    }
 }
\ No newline at end of file
diff --git a/repository/src/main/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClient.java b/repository/src/main/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClient.java
index a6a9ddcaea..3793d80ef8 100644
--- a/repository/src/main/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClient.java
+++ b/repository/src/main/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClient.java
@@ -29,26 +29,29 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;
-import java.io.UnsupportedEncodingException;
+import java.util.List;
 
 import javax.servlet.http.HttpServletResponse;
 
 import org.alfresco.repo.search.QueryParserException;
 import org.apache.commons.httpclient.Header;
 import org.apache.commons.httpclient.HttpClient;
-import org.apache.commons.httpclient.HttpException;
 import org.apache.commons.httpclient.HttpStatus;
 import org.apache.commons.httpclient.URI;
-import org.apache.commons.httpclient.URIException;
 import org.apache.commons.httpclient.methods.PostMethod;
 import org.apache.commons.httpclient.methods.StringRequestEntity;
 import org.apache.commons.httpclient.params.HttpMethodParams;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.json.JSONTokener;
 
 public abstract class AbstractSolrQueryHTTPClient
 {
+    /** Logger for the class. */
+    private static final Log LOGGER = LogFactory.getLog(AbstractSolrQueryHTTPClient.class);
+
     public static final int DEFAULT_SAVEPOST_BUFFER = 4096;
     
     // Constants copied from org.apache.solr.common.params.HighlightParams (solr-solrj:1.4.1)
@@ -79,11 +82,13 @@ public abstract class AbstractSolrQueryHTTPClient
     public static final String HIGHLIGHT_PARAMS_SLOP = HIGHLIGHT_PARAMS_HIGHLIGHT + "." + HIGHLIGHT_PARAMS_REGEX + ".slop";
     public static final String HIGHLIGHT_PARAMS_PATTERN = HIGHLIGHT_PARAMS_HIGHLIGHT + "." + HIGHLIGHT_PARAMS_REGEX + ".pattern";
     public static final String HIGHLIGHT_PARAMS_MAX_RE_CHARS = HIGHLIGHT_PARAMS_HIGHLIGHT + "." + HIGHLIGHT_PARAMS_REGEX + ".maxAnalyzedChars";
+
+    /** List of SOLR Exceptions that should be returning HTTP 501 status code in Remote API. */
+    private static final List<String> STATUS_CODE_501_EXCEPTIONS = List.of("java.lang.UnsupportedOperationException");
     
-    protected JSONObject postQuery(HttpClient httpClient, String url, JSONObject body) throws UnsupportedEncodingException,
-    IOException, HttpException, URIException, JSONException
+    protected JSONObject postQuery(HttpClient httpClient, String url, JSONObject body) throws IOException, JSONException
     {
-        PostMethod post = new PostMethod(url);
+        PostMethod post = createNewPostMethod(url);
         if (body.toString().length() > DEFAULT_SAVEPOST_BUFFER)
         {
             post.getParams().setBooleanParameter(HttpMethodParams.USE_EXPECT_CONTINUE, true);
@@ -103,9 +108,33 @@ public abstract class AbstractSolrQueryHTTPClient
                     httpClient.executeMethod(post);
                 }
             }
+            String responseBodyStr = post.getResponseBodyAsString();
             if (post.getStatusCode() != HttpServletResponse.SC_OK)
             {
-                throw new QueryParserException("Request failed " + post.getStatusCode() + " " + url.toString());
+                String trace = null;
+                try
+                {
+                    trace = new JSONObject(responseBodyStr).getJSONObject("error").getString("trace");
+                }
+                catch (JSONException jsonException)
+                {
+                    LOGGER.warn("Node 'error.trace' is not present in Search Services error response: " + responseBodyStr);
+                    LOGGER.warn("A generic error message will be provided. Check SOLR log file in order to find the root cause for this issue");
+                }
+
+                int httpStatusCode = post.getStatusCode();
+                String message = "Solr request failed with " + httpStatusCode + " " + url;
+
+                // Override the status code for certain exceptions with 501.
+                if (trace != null)
+                {
+                    String traceException = trace.substring(0, trace.indexOf(":")).trim();
+                    if (STATUS_CODE_501_EXCEPTIONS.contains(traceException))
+                    {
+                        httpStatusCode = org.apache.http.HttpStatus.SC_NOT_IMPLEMENTED;
+                    }
+                }
+                throw new QueryParserException(message, httpStatusCode);
             }
 
             Reader reader = new BufferedReader(new InputStreamReader(post.getResponseBodyAsStream(), post.getResponseCharSet()));
@@ -118,4 +147,10 @@ public abstract class AbstractSolrQueryHTTPClient
             post.releaseConnection();
         }
     }
+
+    /** Helper method that can be overridden by unit tests. */
+    protected PostMethod createNewPostMethod(String url)
+    {
+        return new PostMethod(url);
+    }
 }
diff --git a/repository/src/test/java/org/alfresco/AllUnitTestsSuite.java b/repository/src/test/java/org/alfresco/AllUnitTestsSuite.java
index 2ce7585989..75a8e4c9c7 100644
--- a/repository/src/test/java/org/alfresco/AllUnitTestsSuite.java
+++ b/repository/src/test/java/org/alfresco/AllUnitTestsSuite.java
@@ -120,6 +120,9 @@ import org.junit.runners.Suite;
     org.alfresco.util.schemacomp.validator.TypeNameOnlyValidatorTest.class,
     org.alfresco.util.test.OmittedTestClassFinderUnitTest.class,
     org.alfresco.util.test.junitrules.TemporaryMockOverrideTest.class,
+    org.alfresco.repo.search.impl.solr.AbstractSolrQueryHTTPClientTest.class,
+    org.alfresco.repo.search.impl.solr.SpellCheckDecisionManagerTest.class,
+    org.alfresco.repo.search.impl.solr.SolrStoreMappingWrapperTest.class,
     org.alfresco.repo.search.impl.querymodel.impl.db.DBQueryEngineTest.class,
     org.alfresco.repo.search.impl.querymodel.impl.db.NodePermissionAssessorLimitsTest.class,
     org.alfresco.repo.search.impl.querymodel.impl.db.NodePermissionAssessorPermissionsTest.class,
@@ -131,8 +134,6 @@ import org.junit.runners.Suite;
     org.alfresco.repo.search.impl.solr.facet.SolrFacetComparatorTest.class,
     org.alfresco.repo.search.impl.solr.facet.FacetQNameUtilsTest.class,
     org.alfresco.util.BeanExtenderUnitTest.class,
-    org.alfresco.repo.search.impl.solr.SpellCheckDecisionManagerTest.class,
-    org.alfresco.repo.search.impl.solr.SolrStoreMappingWrapperTest.class,
     org.alfresco.repo.solr.SOLRTrackingComponentUnitTest.class,
     org.alfresco.repo.security.authentication.CompositePasswordEncoderTest.class,
     org.alfresco.repo.security.authentication.PasswordHashingTest.class,
diff --git a/repository/src/test/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClientTest.java b/repository/src/test/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClientTest.java
new file mode 100644
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--- /dev/null
+++ b/repository/src/test/java/org/alfresco/repo/search/impl/solr/AbstractSolrQueryHTTPClientTest.java
@@ -0,0 +1,155 @@
+/*
+ * #%L
+ * Alfresco Repository
+ * %%
+ * Copyright (C) 2005 - 2016 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package org.alfresco.repo.search.impl.solr;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.mockito.MockitoAnnotations.openMocks;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.ByteArrayInputStream;
+
+import org.alfresco.repo.search.QueryParserException;
+import org.apache.commons.httpclient.Header;
+import org.apache.commons.httpclient.HttpClient;
+import org.apache.commons.httpclient.URI;
+import org.apache.commons.httpclient.methods.PostMethod;
+import org.json.JSONObject;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+
+/** Tests for the {@link AbstractSolrQueryHTTPClient}. */
+public class AbstractSolrQueryHTTPClientTest
+{
+    /** A URL for use in the tests. */
+    private static final String URL = "http://this/is/a/url";
+
+    /** The abstract class under test. */
+    private AbstractSolrQueryHTTPClient abstractSolrQueryHTTPClient = spy(AbstractSolrQueryHTTPClient.class);
+    @Mock
+    private HttpClient httpClient;
+    @Mock
+    private JSONObject body;
+    @Mock
+    private PostMethod postMethod;
+    @Mock
+    private Header header;
+
+    @Before
+    public void setUp() throws Exception
+    {
+        openMocks(this);
+
+        doReturn(postMethod).when(abstractSolrQueryHTTPClient).createNewPostMethod(URL);
+        when(postMethod.getResponseCharSet()).thenReturn("UTF-8");
+    }
+
+    /** Check postQuery works as expected for the success case. */
+    @Test
+    public void testPostQuery_success() throws Exception
+    {
+        when(body.toString()).thenReturn("Example body");
+        when(postMethod.getStatusCode()).thenReturn(HttpServletResponse.SC_OK);
+        when(postMethod.getResponseBodyAsStream()).thenReturn(convertStringToInputStream("{}"));
+
+        JSONObject response = abstractSolrQueryHTTPClient.postQuery(httpClient, URL, body);
+
+        assertEquals("Unexpected JSON response received.", "{}", response.toString());
+    }
+
+    /** Check that the status code is usually passed through from Solr. */
+    @Test
+    public void testPostQuery_failure() throws Exception
+    {
+        String failureMessage = "{\"error\": {\"trace\": \"ExceptionClass: Stacktrace\"}}";
+
+        when(body.toString()).thenReturn("Example body");
+        when(postMethod.getStatusCode()).thenReturn(HttpServletResponse.SC_NOT_FOUND);
+        when(postMethod.getResponseBodyAsStream()).thenReturn(convertStringToInputStream(failureMessage));
+        when(postMethod.getResponseBodyAsString()).thenReturn(failureMessage);
+
+        try
+        {
+            abstractSolrQueryHTTPClient.postQuery(httpClient, URL, body);
+            fail("Expected a QueryParserException to be thrown.");
+        }
+        catch (QueryParserException e)
+        {
+            assertEquals("Unexpected status code in exception.", e.getHttpStatusCode(), HttpServletResponse.SC_NOT_FOUND);
+            verify(postMethod).releaseConnection();
+        }
+    }
+
+    /** Check that the status code is replaced with "Not Implemented" for an unsupported query option. */
+    @Test
+    public void testPostQuery_unsupportedOperation() throws Exception
+    {
+        String failureMessage = "{\"error\": {\"trace\": \"java.lang.UnsupportedOperationException: Stacktrace\"}}";
+
+        when(body.toString()).thenReturn("Example body");
+        when(postMethod.getStatusCode()).thenReturn(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+        when(postMethod.getResponseBodyAsStream()).thenReturn(convertStringToInputStream(failureMessage));
+        when(postMethod.getResponseBodyAsString()).thenReturn(failureMessage);
+
+        try
+        {
+            abstractSolrQueryHTTPClient.postQuery(httpClient, URL, body);
+            fail("Expected a QueryParserException to be thrown.");
+        }
+        catch (QueryParserException e)
+        {
+            assertEquals("Unexpected status code in exception.", e.getHttpStatusCode(), HttpServletResponse.SC_NOT_IMPLEMENTED);
+        }
+    }
+
+    /** Check that a redirect can be followed if the endpoint reports that it's moved. */
+    @Test
+    public void testPostQuery_moved() throws Exception
+    {
+        when(body.toString()).thenReturn("Example body");
+        // Report "moved" for the first invocation and then OK for subsequent requests.
+        when(postMethod.getStatusCode()).thenReturn(HttpServletResponse.SC_MOVED_PERMANENTLY).thenReturn(HttpServletResponse.SC_OK);
+        when(postMethod.getResponseBodyAsStream()).thenReturn(convertStringToInputStream("{}"));
+        when(postMethod.getResponseHeader("location")).thenReturn(header);
+        when(header.getValue()).thenReturn("http://new/URL");
+
+        JSONObject response = abstractSolrQueryHTTPClient.postQuery(httpClient, URL, body);
+
+        verify(postMethod).setURI(new URI("http://new/URL", true));
+        assertEquals("Unexpected JSON response received.", "{}", response.toString());
+    }
+
+    /** Create an input stream containing the given string. */
+    private ByteArrayInputStream convertStringToInputStream(String message)
+    {
+        return new ByteArrayInputStream(message.getBytes());
+    }
+}