Enable routing of SQL queries at Router

docs/configuration/index.md

@@ -2052,6 +2052,7 @@ Supported query contexts:
 |`druid.router.tierToBrokerMap`|Queries for a certain tier of data are routed to their appropriate Broker. This value should be an ordered JSON map of tiers to Broker names. The priority of Brokers is based on the ordering.|{"_default_tier": "<defaultBrokerServiceName>"}|
 |`druid.router.defaultRule`|The default rule for all datasources.|"_default"|
 |`druid.router.pollPeriod`|How often to poll for new rules.|PT1M|
+|`druid.router.sql.enable`|Enable routing of SQL queries. Possible values are `true` and `false`. When set to `true`, the Router uses the provided strategies to determine the broker service for a given SQL query.|`false`|
 |`druid.router.strategies`|Please see [Router Strategies](../design/router.md#router-strategies) for details.|[{"type":"timeBoundary"},{"type":"priority"}]|
 |`druid.router.avatica.balancer.type`|Class to use for balancing Avatica queries across Brokers. Please see [Avatica Query Balancing](../design/router.md#avatica-query-balancing).|rendezvousHash|
 |`druid.router.managementProxy.enabled`|Enables the Router's [management proxy](../design/router.md#router-as-management-proxy) functionality.|false|

docs/design/router.md

@@ -112,6 +112,7 @@ Queries with a priority set to less than minPriority are routed to the lowest pr
 #### manual
 
 This strategy reads the parameter `brokerService` from the query context and routes the query to that broker service. If no valid `brokerService` is specified in the query context, the field `defaultManualBrokerService` is used to determine target broker service given the value is valid and non-null. A value is considered valid if it is present in `druid.router.tierToBrokerMap`
+This strategy can route both Native and SQL queries (when enabled).
 
 *Example*: A strategy that routes queries to the Broker "druid:broker-hot" if no valid `brokerService` is found in the query context.
 
@@ -137,6 +138,18 @@ Allows defining arbitrary routing rules using a JavaScript function. The functio
 
 > JavaScript-based functionality is disabled by default. Please refer to the Druid [JavaScript programming guide](../development/javascript.md) for guidelines about using Druid's JavaScript functionality, including instructions on how to enable it.
 
+### Routing of SQL queries
+
+To enable routing of SQL queries, set `druid.router.sql.enable` to `true` (`false` by default). The broker service for a
+given SQL query is resolved using only the provided Router strategies. If not resolved using any of the strategies, the
+Router uses the `defaultBrokerServiceName`. This behavior is slightly different from native queries where the Router
+first tries to resolve the broker service using strategies, then load rules and finally using the `defaultBrokerServiceName`
+if still not resolved.
+
+Routing of native queries is always enabled.
+
+Setting `druid.router.sql.enable` does not affect Avatica JDBC requests. They are routed based on connection ID as
+explained in the next section.
 
 ### Avatica query balancing
 

extensions-core/hdfs-storage/pom.xml

@@ -377,6 +377,11 @@
           <artifactId>junit</artifactId>
           <scope>test</scope>
         </dependency>
+        <dependency>
+          <groupId>com.google.protobuf</groupId>
+          <artifactId>protobuf-java</artifactId>
+          <scope>test</scope>
+        </dependency>
         <dependency>
           <groupId>org.apache.druid</groupId>
           <artifactId>druid-server</artifactId>

processing/src/main/java/org/apache/druid/query/QueryContexts.java

@@ -329,6 +329,11 @@ public static <T> boolean isDebug(Query<T> query)
     return parseBoolean(query, ENABLE_DEBUG, DEFAULT_ENABLE_DEBUG);
   }
 
+  public static boolean isDebug(Map<String, Object> queryContext)
+  {
+    return parseBoolean(queryContext, ENABLE_DEBUG, DEFAULT_ENABLE_DEBUG);
+  }
+
   public static <T> Query<T> withMaxScatterGatherBytes(Query<T> query, long maxScatterGatherBytesLimit)
   {
     Object obj = query.getContextValue(MAX_SCATTER_GATHER_BYTES_KEY);
@@ -418,9 +423,9 @@ public static <T> boolean allowReturnPartialResults(Query<T> query, boolean defa
     return query.getContextBoolean(RETURN_PARTIAL_RESULTS_KEY, defaultValue);
   }
 
-  public static <T> String getBrokerServiceName(Query<T> query)
+  public static String getBrokerServiceName(Map<String, Object> queryContext)
   {
-    return query.getContextValue(BROKER_SERVICE_NAME);
+    return queryContext == null ? null : (String) queryContext.get(BROKER_SERVICE_NAME);
   }
 
   static <T> long parseLong(Query<T> query, String key, long defaultValue)

processing/src/test/java/org/apache/druid/query/QueryContextsTest.java

@@ -30,6 +30,7 @@
 import org.junit.rules.ExpectedException;
 
 import java.util.HashMap;
+import java.util.Map;
 
 public class QueryContextsTest
 {
@@ -149,33 +150,21 @@ public void testGetEnableJoinLeftScanDirect()
   @Test
   public void testGetBrokerServiceName()
   {
-    Query<?> query = new TestQuery(
-        new TableDataSource("test"),
-        new MultipleIntervalSegmentSpec(ImmutableList.of(Intervals.of("0/100"))),
-        false,
-        new HashMap<>()
-    );
-
-    Assert.assertNull(QueryContexts.getBrokerServiceName(query));
+    Map<String, Object> queryContext = new HashMap<>();
+    Assert.assertNull(QueryContexts.getBrokerServiceName(queryContext));
 
-    query.getContext().put(QueryContexts.BROKER_SERVICE_NAME, "hotBroker");
-    Assert.assertEquals("hotBroker", QueryContexts.getBrokerServiceName(query));
+    queryContext.put(QueryContexts.BROKER_SERVICE_NAME, "hotBroker");
+    Assert.assertEquals("hotBroker", QueryContexts.getBrokerServiceName(queryContext));
   }
 
   @Test
   public void testGetBrokerServiceName_withNonStringValue()
   {
-    Query<?> query = new TestQuery(
-        new TableDataSource("test"),
-        new MultipleIntervalSegmentSpec(ImmutableList.of(Intervals.of("0/100"))),
-        false,
-        new HashMap<>()
-    );
-
-    query.getContext().put(QueryContexts.BROKER_SERVICE_NAME, 100);
+    Map<String, Object> queryContext = new HashMap<>();
+    queryContext.put(QueryContexts.BROKER_SERVICE_NAME, 100);
 
     exception.expect(ClassCastException.class);
-    QueryContexts.getBrokerServiceName(query);
+    QueryContexts.getBrokerServiceName(queryContext);
   }
 
   @Test
@@ -188,6 +177,7 @@ public void testDefaultEnableQueryDebugging()
         ImmutableMap.of()
     );
     Assert.assertFalse(QueryContexts.isDebug(query));
+    Assert.assertFalse(QueryContexts.isDebug(query.getContext()));
   }
 
   @Test
@@ -200,5 +190,6 @@ public void testEnableQueryDebuggingSetToTrue()
         ImmutableMap.of(QueryContexts.ENABLE_DEBUG, true)
     );
     Assert.assertTrue(QueryContexts.isDebug(query));
+    Assert.assertTrue(QueryContexts.isDebug(query.getContext()));
   }
 }

server/pom.xml

@@ -323,10 +323,6 @@
             <groupId>com.fasterxml.jackson.module</groupId>
             <artifactId>jackson-module-guice</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.apache.calcite.avatica</groupId>
-            <artifactId>avatica-core</artifactId>
-        </dependency>
 
         <!-- Tests -->
         <dependency>

services/pom.xml

@@ -80,6 +80,18 @@
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.eclipse.jetty</groupId>
+            <artifactId>jetty-client</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.eclipse.jetty</groupId>
+            <artifactId>jetty-http</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.eclipse.jetty</groupId>
+            <artifactId>jetty-proxy</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-server</artifactId>
@@ -88,6 +100,10 @@
             <groupId>org.apache.curator</groupId>
             <artifactId>curator-framework</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.calcite.avatica</groupId>
+            <artifactId>avatica-core</artifactId>
+        </dependency>
         <dependency>
             <groupId>joda-time</groupId>
             <artifactId>joda-time</artifactId>
@@ -96,14 +112,38 @@
             <groupId>com.google.inject</groupId>
             <artifactId>guice</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.jaxrs</groupId>
+            <artifactId>jackson-jaxrs-smile-provider</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.opencsv</groupId>
             <artifactId>opencsv</artifactId>
         </dependency>
+        <dependency>
+            <groupId>javax.validation</groupId>
+            <artifactId>validation-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.google.errorprone</groupId>
+            <artifactId>error_prone_annotations</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>commons-lang</groupId>
+            <artifactId>commons-lang</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>javax.ws.rs</groupId>
+            <artifactId>jsr311-api</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-servlet</artifactId>
@@ -112,6 +152,10 @@
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-rewrite</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.sun.jersey</groupId>
+            <artifactId>jersey-server</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.google.inject.extensions</groupId>
             <artifactId>guice-multibindings</artifactId>
@@ -124,6 +168,10 @@
             <groupId>org.eclipse.jetty</groupId>
             <artifactId>jetty-util</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.netty</groupId>
+            <artifactId>netty</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-common</artifactId>
@@ -161,6 +209,27 @@
             <artifactId>jaxb-api</artifactId>
         </dependency>
         <!-- Test Dependencies -->
+        <dependency>
+            <groupId>org.apache.druid</groupId>
+            <artifactId>druid-core</artifactId>
+            <version>${project.parent.version}</version>
+            <type>test-jar</type>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.druid</groupId>
+            <artifactId>druid-server</artifactId>
+            <version>${project.parent.version}</version>
+            <type>test-jar</type>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.druid</groupId>
+            <artifactId>druid-processing</artifactId>
+            <version>${project.parent.version}</version>
+            <type>test-jar</type>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
@@ -176,6 +245,11 @@
             <artifactId>hamcrest-core</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.easymock</groupId>
+            <artifactId>easymock</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>