ZOOKEEPER-3898: Fix typos

Author: dk.technoboy <guo.jiwei@immomo.com>

Reviewers: Enrico Olivelli <eolivelli@apache.org>, maoling <maoling199210191@sina.com>

Closes #1414 from Technoboy-/typos
diff --git a/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java b/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
index 5c3f5f4..d48a7bf 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java
@@ -1224,7 +1224,7 @@ public void setSecureServerCnxnFactory(ServerCnxnFactory factory) {
     }
 
     /**
-     * return the last proceesed id from the
+     * return the last processed id from the
      * datatree
      */
     public long getLastProcessedZxid() {
@@ -1233,7 +1233,7 @@ public long getLastProcessedZxid() {
 
     /**
      * return the outstanding requests
-     * in the queue, which havent been
+     * in the queue, which haven't been
      * processed yet
      */
     public long getOutstandingRequests() {
@@ -1259,7 +1259,7 @@ public int getNumAliveConnections() {
     }
 
     /**
-     * trunccate the log to get in sync with others
+     * truncate the log to get in sync with others
      * if in a quorum
      * @param zxid the zxid that it needs to get in sync
      * with others
diff --git a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumPeerConfig.java b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumPeerConfig.java
index f3f456e..7a73180 100644
--- a/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumPeerConfig.java
+++ b/zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumPeerConfig.java
@@ -712,7 +712,7 @@ public static QuorumVerifier parseDynamicConfig(Properties dynamicConfigProp, in
                 if (numParticipators <= 2) {
                     LOG.warn("No server failure will be tolerated. You need at least 3 servers.");
                 } else if (numParticipators % 2 == 0) {
-                    LOG.warn("Non-optimial configuration, consider an odd number of servers.");
+                    LOG.warn("Non-optimal configuration, consider an odd number of servers.");
                 }
             }