Add config for http client connect timeout

docs/configuration/index.md

@@ -841,6 +841,7 @@ All Druid components can communicate with each other over HTTP.
 |`druid.global.http.readTimeout`|The timeout for data reads.|`PT15M`|
 |`druid.global.http.unusedConnectionTimeout`|The timeout for idle connections in connection pool. The connection in the pool will be closed after this timeout and a new one will be established. This timeout should be less than `druid.global.http.readTimeout`. Set this timeout = ~90% of `druid.global.http.readTimeout`|`PT4M`|
 |`druid.global.http.numMaxThreads`|Maximum number of I/O worker threads|`max(10, ((number of cores * 17) / 16 + 2) + 30)`|
+|`druid.global.http.clientConnectTimeout`|The timeout (in milliseconds) for establishing client connections.|500|
 
 ### Common endpoints configuration
 
@@ -1880,6 +1881,8 @@ client has the following configuration options.
 |`druid.broker.http.unusedConnectionTimeout`|The timeout for idle connections in connection pool. The connection in the pool will be closed after this timeout and a new one will be established. This timeout should be less than `druid.broker.http.readTimeout`. Set this timeout = ~90% of `druid.broker.http.readTimeout`|`PT4M`|
 |`druid.broker.http.maxQueuedBytes`|Maximum number of bytes queued per query before exerting [backpressure](../operations/basic-cluster-tuning.md#broker-backpressure) on channels to the data servers.<br /><br />Similar to `druid.server.http.maxScatterGatherBytes`, except that `maxQueuedBytes` triggers [backpressure](../operations/basic-cluster-tuning.md#broker-backpressure) instead of query failure. Set to zero to disable. You can override this setting by using the [`maxQueuedBytes` query context parameter](../querying/query-context.md). Druid supports [human-readable](human-readable-byte.md) format. |25 MB or 2% of maximum Broker heap size, whichever is greater.|
 |`druid.broker.http.numMaxThreads`|`Maximum number of I/O worker threads|max(10, ((number of cores * 17) / 16 + 2) + 30)`|
+|`druid.broker.http.clientConnectTimeout`|The timeout (in milliseconds) for establishing client connections.|500|
+
 
 ##### Retry policy
 
@@ -2240,3 +2243,4 @@ Supported query contexts:
 |`druid.router.http.numMaxThreads`|Maximum number of worker threads to handle HTTP requests and responses|`max(10, ((number of cores * 17) / 16 + 2) + 30)`|
 |`druid.router.http.numRequestsQueued`|Maximum number of requests that may be queued to a destination|`1024`|
 |`druid.router.http.requestBuffersize`|Size of the content buffer for receiving requests. These buffers are only used for active connections that have requests with bodies that will not fit within the header buffer|`8 * 1024`|
+|`druid.router.http.clientConnectTimeout`|The timeout (in milliseconds) for establishing client connections.|500|

server/src/main/java/org/apache/druid/guice/http/DruidHttpClientConfig.java

@@ -27,6 +27,7 @@
 import org.joda.time.Period;
 
 import javax.validation.constraints.Min;
+import java.util.concurrent.TimeUnit;
 
 /**
  *
@@ -72,6 +73,9 @@ public class DruidHttpClientConfig
   @JsonProperty
   private Boolean eagerInitialization = null;
 
+  @JsonProperty
+  private long clientConnectTimeout = TimeUnit.MILLISECONDS.toMillis(500);
+
   public int getNumConnections()
   {
     return numConnections;
@@ -129,6 +133,11 @@ public boolean isEagerInitialization(boolean defaultValue)
     return eagerInitialization;
   }
 
+  public long getClientConnectTimeout()
+  {
+    return clientConnectTimeout;
+  }
+
   private static HumanReadableBytes computeDefaultMaxQueuedBytes()
   {
     return HumanReadableBytes.valueOf(

server/src/main/java/org/apache/druid/guice/http/JettyHttpClientModule.java

@@ -33,15 +33,12 @@
 
 import javax.net.ssl.SSLContext;
 import java.lang.annotation.Annotation;
-import java.util.concurrent.TimeUnit;
 
 /**
  *
  */
 public class JettyHttpClientModule implements Module
 {
-  private static final long CLIENT_CONNECT_TIMEOUT_MILLIS = TimeUnit.MILLISECONDS.toMillis(500);
-
   public static JettyHttpClientModule global()
   {
     return new JettyHttpClientModule("druid.global.http", Global.class);
@@ -91,7 +88,7 @@ public HttpClient get()
       httpClient.setIdleTimeout(config.getReadTimeout().getMillis());
       httpClient.setMaxConnectionsPerDestination(config.getNumConnections());
       httpClient.setMaxRequestsQueuedPerDestination(config.getNumRequestsQueued());
-      httpClient.setConnectTimeout(CLIENT_CONNECT_TIMEOUT_MILLIS);
+      httpClient.setConnectTimeout(config.getClientConnectTimeout());
       httpClient.setRequestBufferSize(config.getRequestBuffersize());
       final QueuedThreadPool pool = new QueuedThreadPool(config.getNumMaxThreads());
       pool.setName(JettyHttpClientModule.class.getSimpleName() + "-threadPool-" + pool.hashCode());