From 66933d6f5760a93cf4e26c33e33dbb17c041e289 Mon Sep 17 00:00:00 2001
From: Tom Pantelis <tpanteli@brocade.com>
Date: Wed, 8 Apr 2015 14:09:46 -0400
Subject: [PATCH] Add LeadershipChangeCount to ShardStats

It's useful to see how many shard leadership changes have occurred so I
added a LeadershipChangeCount stat to the ShardStats mbean. This helps
to determine if spurious leadership changes are occurring. I also added
LastLeadershipChangeTime.

Change-Id: I33ddbcd96d6fa93fbfa9887393a2f5a40027d9f3
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>
---
 .../controller/cluster/datastore/Shard.java   |  5 +++++
 .../jmx/mbeans/shard/ShardStats.java          | 19 +++++++++++++++++++
 .../jmx/mbeans/shard/ShardStatsMXBean.java    |  4 ++++
 3 files changed, 28 insertions(+)

diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/Shard.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/Shard.java
index 81449c5747..7110adc625 100644
--- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/Shard.java
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/Shard.java
@@ -701,6 +701,11 @@ public class Shard extends RaftActor {
         }
     }
 
+    @Override
+    protected void onLeaderChanged(String oldLeader, String newLeader) {
+        shardMBean.incrementLeadershipChangeCount();
+    }
+
     @Override
     public String persistenceId() {
         return this.name;
diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStats.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStats.java
index fb59b7643f..e3c8ced878 100644
--- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStats.java
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStats.java
@@ -77,6 +77,10 @@ public class ShardStats extends AbstractMXBean implements ShardStatsMXBean {
 
     private String statRetrievalTime;
 
+    private long leadershipChangeCount;
+
+    private long lastLeadershipChangeTime;
+
     public ShardStats(final String shardName, final String mxBeanType) {
         super(shardName, mxBeanType, JMX_CATEGORY_SHARD);
     }
@@ -366,4 +370,19 @@ public class ShardStats extends AbstractMXBean implements ShardStatsMXBean {
         getOnDemandRaftState();
         return statRetrievalError;
     }
+
+    @Override
+    public long getLeadershipChangeCount() {
+        return leadershipChangeCount;
+    }
+
+    public void incrementLeadershipChangeCount() {
+        leadershipChangeCount++;
+        lastLeadershipChangeTime = System.currentTimeMillis();
+    }
+
+    @Override
+    public String getLastLeadershipChangeTime() {
+        return DATE_FORMAT.format(new Date(lastLeadershipChangeTime));
+    }
 }
diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStatsMXBean.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStatsMXBean.java
index 1c0c83b699..12cea50e44 100644
--- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStatsMXBean.java
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/jmx/mbeans/shard/ShardStatsMXBean.java
@@ -79,4 +79,8 @@ public interface ShardStatsMXBean {
    List<FollowerInfo> getFollowerInfo();
 
    String getPeerAddresses();
+
+   long getLeadershipChangeCount();
+
+   String getLastLeadershipChangeTime();
 }
-- 
2.36.6