Fix connection stickiness

Author: mpv1989

ChangeLog.md

@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 ### Fixed
 
 - fixed `ArangoCursor#next` when performing a dirty read
+- fixed connection stickiness
 
 ## [5.0.0] - 2018-09-18
 

src/main/java/com/arangodb/internal/http/HttpCommunication.java

@@ -91,6 +91,9 @@ public Response execute(final Request request, final HostHandle hostHandle) thro
 					return response;
 				} catch (final SocketException se) {
 					hostHandler.fail();
+					if (hostHandle != null && hostHandle.getHost() != null) {
+						hostHandle.setHost(null);
+					}
 					final Host failedHost = host;
 					host = hostHandler.get(hostHandle, accessType);
 					if (host != null) {

src/main/java/com/arangodb/internal/velocystream/VstCommunication.java

@@ -101,6 +101,9 @@ protected synchronized C connect(final HostHandle hostHandle, final AccessType a
 					return connection;
 				} catch (final IOException e) {
 					hostHandler.fail();
+					if (hostHandle != null && hostHandle.getHost() != null) {
+						hostHandle.setHost(null);
+					}
 					final Host failedHost = host;
 					host = hostHandler.get(hostHandle, accessType);
 					if (host != null) {