[incubator-ratis] branch master updated: RATIS-1041. Change client to try the servers according to the priority (#186)

[szetszwo]

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szetszwo pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-ratis.git


The following commit(s) were added to refs/heads/master by this push:
     new 3a98407  RATIS-1041. Change client to try the servers according to the 
priority (#186)
3a98407 is described below

commit 3a98407f0039c5d45806c557037ea6af00c69608
Author: runzhiwang <51938049+runzhiw...@users.noreply.github.com>
AuthorDate: Mon Aug 31 12:56:51 2020 +0800

    RATIS-1041. Change client to try the servers according to the priority 
(#186)
---
 .../java/org/apache/ratis/client/RaftClient.java   |  3 +++
 .../apache/ratis/client/impl/RaftClientImpl.java   | 24 ++++++++++++++++++++--
 .../ratis/server/impl/GroupManagementBaseTest.java |  2 ++
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/ratis-client/src/main/java/org/apache/ratis/client/RaftClient.java 
b/ratis-client/src/main/java/org/apache/ratis/client/RaftClient.java
index e70054c..37f889c 100644
--- a/ratis-client/src/main/java/org/apache/ratis/client/RaftClient.java
+++ b/ratis-client/src/main/java/org/apache/ratis/client/RaftClient.java
@@ -42,6 +42,9 @@ public interface RaftClient extends Closeable {
   /** @return the id of this client. */
   ClientId getId();
 
+  /** @return the cluster leaderId recorded by this client. */
+  RaftPeerId getLeaderId();
+
   /** @return the client rpct. */
   RaftClientRpc getClientRpc();
 
diff --git 
a/ratis-client/src/main/java/org/apache/ratis/client/impl/RaftClientImpl.java 
b/ratis-client/src/main/java/org/apache/ratis/client/impl/RaftClientImpl.java
index b69a53a..8f00e50 100644
--- 
a/ratis-client/src/main/java/org/apache/ratis/client/impl/RaftClientImpl.java
+++ 
b/ratis-client/src/main/java/org/apache/ratis/client/impl/RaftClientImpl.java
@@ -116,8 +116,7 @@ public final class RaftClientImpl implements RaftClient {
     this.clientRpc = clientRpc;
     this.peers = new ConcurrentLinkedQueue<>(group.getPeers());
     this.groupId = group.getGroupId();
-    this.leaderId = leaderId != null? leaderId
-        : !peers.isEmpty()? peers.iterator().next().getId(): null;
+    this.leaderId = leaderId != null? leaderId : getHighestPriorityPeerId();
     Preconditions.assertTrue(retryPolicy != null, "retry policy can't be 
null");
     this.retryPolicy = retryPolicy;
 
@@ -128,6 +127,27 @@ public final class RaftClientImpl implements RaftClient {
     this.streamApi = JavaUtils.memoize(() -> StreamImpl.newInstance(this, 
properties));
   }
 
+  public RaftPeerId getLeaderId() {
+    return leaderId;
+  }
+
+  private RaftPeerId getHighestPriorityPeerId() {
+    if (peers == null) {
+      return null;
+    }
+
+    int maxPriority = Integer.MIN_VALUE;
+    RaftPeerId highestPriorityPeerId = null;
+    for (RaftPeer peer : peers) {
+      if (maxPriority < peer.getPriority()) {
+        maxPriority = peer.getPriority();
+        highestPriorityPeerId = peer.getId();
+      }
+    }
+
+    return highestPriorityPeerId;
+  }
+
   @Override
   public ClientId getId() {
     return clientId;
diff --git 
a/ratis-server/src/test/java/org/apache/ratis/server/impl/GroupManagementBaseTest.java
 
b/ratis-server/src/test/java/org/apache/ratis/server/impl/GroupManagementBaseTest.java
index fa9aca7..a8cc541 100644
--- 
a/ratis-server/src/test/java/org/apache/ratis/server/impl/GroupManagementBaseTest.java
+++ 
b/ratis-server/src/test/java/org/apache/ratis/server/impl/GroupManagementBaseTest.java
@@ -112,6 +112,8 @@ public abstract class GroupManagementBaseTest extends 
BaseTest {
     final RaftGroup newGroup = RaftGroup.valueOf(RaftGroupId.randomId(), 
peersWithPriority);
     LOG.info("add new group: " + newGroup);
     try (final RaftClient client = cluster.createClient(newGroup)) {
+      // Before request, client try leader with the highest priority
+      Assert.assertTrue(client.getLeaderId() == 
peersWithPriority.get(suggestedLeaderIndex).getId());
       for (RaftPeer p : newGroup.getPeers()) {
         client.groupAdd(newGroup, p.getId());
       }