Configurable HTTP compression. (#3759)

* Configurable HTTP compression.

* Call real-time nodes real-time processes in docs.

docs/content/configuration/broker.md

@@ -36,8 +36,9 @@ Druid uses Jetty to serve HTTP requests.
 |--------|-----------|-------|
 |`druid.server.http.numThreads`|Number of threads for HTTP requests.|10|
 |`druid.server.http.maxIdleTime`|The Jetty max idle time for a connection.|PT5m|
-|`druid.broker.http.numConnections`|Size of connection pool for the Broker to connect to historical and real-time nodes. If there are more queries than this number that all need to speak to the same node, then they will queue up.|20|
+|`druid.broker.http.numConnections`|Size of connection pool for the Broker to connect to historical and real-time processes. If there are more queries than this number that all need to speak to the same node, then they will queue up.|20|
-|`druid.broker.http.readTimeout`|The timeout for data reads.|PT15M|
+|`druid.broker.http.compressionCodec`|Compression codec the Broker uses to communicate with historical and real-time processes. May be "gzip" or "identity".|gzip|
+|`druid.broker.http.readTimeout`|The timeout for data reads from historical and real-time processes.|PT15M|
 
 #### Retry Policy
 

pom.xml

@@ -128,7 +128,7 @@
             <dependency>
                 <groupId>com.metamx</groupId>
                 <artifactId>http-client</artifactId>
-                <version>1.0.5</version>
+                <version>1.0.6</version>
             </dependency>
             <dependency>
                 <groupId>com.metamx</groupId>

server/src/main/java/io/druid/guice/http/DruidHttpClientConfig.java

@@ -30,6 +30,8 @@ import javax.validation.constraints.Min;
 
 public class DruidHttpClientConfig
 {
+  private final String DEFAULT_COMPRESSION_CODEC = "gzip";
+
   @JsonProperty
   @Min(0)
   private int numConnections = 20;
@@ -41,6 +43,9 @@ public class DruidHttpClientConfig
   @Min(1)
   private int numMaxThreads = Math.max(10, (Runtime.getRuntime().availableProcessors() * 17) / 16 + 2) + 30;
 
+  @JsonProperty
+  private String compressionCodec = DEFAULT_COMPRESSION_CODEC;
+
   public int getNumConnections()
   {
     return numConnections;
@@ -55,4 +60,9 @@ public class DruidHttpClientConfig
   {
     return numMaxThreads;
   }
+
+  public String getCompressionCodec()
+  {
+    return compressionCodec;
+  }
 }

server/src/main/java/io/druid/guice/http/HttpClientModule.java

@@ -108,7 +108,8 @@ public class HttpClientModule implements Module
           .builder()
           .withNumConnections(config.getNumConnections())
           .withReadTimeout(config.getReadTimeout())
-          .withWorkerCount(config.getNumMaxThreads());
+          .withWorkerCount(config.getNumMaxThreads())
+          .withCompressionCodec(HttpClientConfig.CompressionCodec.valueOf(config.getCompressionCodec().toUpperCase()));
 
       if (getSslContextBinding() != null) {
         builder.withSslContext(getSslContextBinding().getProvider().get());