[zookeeper] branch master updated: ZOOKEEPER-3218: Add min notification interval property for fast leader election

[fangmin]

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fangmin pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/zookeeper.git


The following commit(s) were added to refs/heads/master by this push:
     new 0b504de  ZOOKEEPER-3218: Add min notification interval property for 
fast leader election
0b504de is described below

commit 0b504dec95b09acb05b40505588f7cda8131fea6
Author: Brian Nixon <ni...@fb.com>
AuthorDate: Fri Jan 18 10:42:12 2019 +0800

    ZOOKEEPER-3218: Add min notification interval property for fast leader 
election
    
    …to the new leader is too long，then session expired
    
    Author: Brian Nixon <ni...@fb.com>
    
    Reviewers: fang...@apache.org, eolive...@apache.org
    
    Closes #747 from enixon/noti-inter
---
 .../src/main/resources/markdown/zookeeperAdmin.md  | 18 +++++++++++++
 .../server/quorum/FastLeaderElection.java          | 31 ++++++++++++++++++++--
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md 
b/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md
index d808b61..95787b7 100644
--- a/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md
+++ b/zookeeper-docs/src/main/resources/markdown/zookeeperAdmin.md
@@ -720,6 +720,24 @@ property, when available, is noted below.
     of the observers on restart. Set to "false" to disable this
     feature. Default is "true"
 
+* *fastleader.minNotificationInterval* :
+    (Java system property: **zookeeper.fastleader.minNotificationInterval**)
+    Lower bound for length of time between two consecutive notification
+    checks on the leader election. This interval determines how long a
+    peer waits to check the set of election votes and effects how
+    quickly an election can resolve. The interval follows a backoff
+    strategy from the configured minimum (this) and the configured maximum
+    (fastleader.maxNotificationInterval) for long elections.
+
+* *fastleader.maxNotificationInterval* :
+    (Java system property: **zookeeper.fastleader.maxNotificationInterval**)
+    Upper bound for length of time between two consecutive notification
+    checks on the leader election. This interval determines how long a
+    peer waits to check the set of election votes and effects how
+    quickly an election can resolve. The interval follows a backoff
+    strategy from the configured minimum (fastleader.minNotificationInterval)
+    and the configured maximum (this) for long elections.
+
 <a name="sc_clusterOptions"></a>
 
 #### Cluster Options
diff --git 
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/FastLeaderElection.java
 
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/FastLeaderElection.java
index 84e269c..9ebdabd 100644
--- 
a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/FastLeaderElection.java
+++ 
b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/FastLeaderElection.java
@@ -68,7 +68,34 @@ public class FastLeaderElection implements Election {
      * the system up again after long partitions. Currently 60 seconds.
      */
 
-    final static int maxNotificationInterval = 60000;
+    private static int maxNotificationInterval = 60000;
+
+    /**
+     * Lower bound for notification check. The observer don't need to use
+     * the same lower bound as participant members
+     */
+    private static int minNotificationInterval = finalizeWait;
+
+    /**
+     * Minimum notification interval, default is equal to finalizeWait
+     */
+    public static final String MIN_NOTIFICATION_INTERVAL =
+            "zookeeper.fastleader.minNotificationInterval";
+
+    /**
+     * Maximum notification interval, default is 60s
+     */
+    public static final String MAX_NOTIFICATION_INTERVAL =
+            "zookeeper.fastleader.maxNotificationInterval";
+
+    static {
+        minNotificationInterval = Integer.getInteger(MIN_NOTIFICATION_INTERVAL,
+                minNotificationInterval);
+        LOG.info("{}={}", MIN_NOTIFICATION_INTERVAL, minNotificationInterval);
+        maxNotificationInterval = Integer.getInteger(MAX_NOTIFICATION_INTERVAL,
+                maxNotificationInterval);
+        LOG.info("{}={}", MAX_NOTIFICATION_INTERVAL, maxNotificationInterval);
+    }
 
     /**
      * Connection manager. Fast leader election uses TCP for
@@ -898,7 +925,7 @@ public class FastLeaderElection implements Election {
 
             Map<Long, Vote> outofelection = new HashMap<Long, Vote>();
 
-            int notTimeout = finalizeWait;
+            int notTimeout = minNotificationInterval;
 
             synchronized(this){
                 logicalclock.incrementAndGet();