diff --git a/CHANGES.txt b/CHANGES.txt
index 4478dba6f6..1b2827270d 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -465,6 +465,8 @@ Trunk (unreleased changes)
     commands that do not complete within a certain amount of time.
     (Sreekanth Ramakrishnan via yhemanth)
 
+    HADOOP-5925. EC2 scripts should exit on error. (tomwhite)
+
   OPTIMIZATIONS
 
     HADOOP-5595. NameNode does not need to run a replicator to choose a
diff --git a/src/contrib/ec2/bin/cmd-hadoop-cluster b/src/contrib/ec2/bin/cmd-hadoop-cluster
index a4570a2dc7..5678dee8f9 100644
--- a/src/contrib/ec2/bin/cmd-hadoop-cluster
+++ b/src/contrib/ec2/bin/cmd-hadoop-cluster
@@ -17,6 +17,8 @@
 
 # Run commands on master or specified node of a running Hadoop EC2 cluster.
 
+set -o errexit
+
 # if no args specified, show usage
 if [ $# = 0 ]; then
   echo "Command required!"
diff --git a/src/contrib/ec2/bin/create-hadoop-image b/src/contrib/ec2/bin/create-hadoop-image
index 31b3048586..98064c2d31 100755
--- a/src/contrib/ec2/bin/create-hadoop-image
+++ b/src/contrib/ec2/bin/create-hadoop-image
@@ -18,6 +18,8 @@
 # Create a Hadoop AMI.
 # Inspired by Jonathan Siegel's EC2 script (http://blogsiegel.blogspot.com/2006/08/sandboxing-amazon-ec2.html)
 
+set -o errexit
+
 # Import variables
 bin=`dirname "$0"`
 bin=`cd "$bin"; pwd`
diff --git a/src/contrib/ec2/bin/delete-hadoop-cluster b/src/contrib/ec2/bin/delete-hadoop-cluster
index a070d34e2b..96e8d5b4d7 100644
--- a/src/contrib/ec2/bin/delete-hadoop-cluster
+++ b/src/contrib/ec2/bin/delete-hadoop-cluster
@@ -15,7 +15,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Delete the groups an local files associated with a cluster.
+# Delete the groups and local files associated with a cluster.
+
+set -o errexit
 
 if [ -z $1 ]; then
   echo "Cluster name required!"
@@ -42,17 +44,17 @@ bin=`cd "$bin"; pwd`
 rm -f $MASTER_IP_PATH
 rm -f $MASTER_PRIVATE_IP_PATH
 
-ec2-describe-group | egrep "[[:space:]]$CLUSTER_MASTER[[:space:]]" > /dev/null
-if [ $? -eq 0 ]; then
+if ec2-describe-group $CLUSTER_MASTER > /dev/null 2>&1; then
+  if ec2-describe-group $CLUSTER > /dev/null 2>&1; then
+    echo "Revoking authorization between $CLUSTER_MASTER and $CLUSTER"
+    ec2-revoke $CLUSTER_MASTER -o $CLUSTER -u $AWS_ACCOUNT_ID || true
+    ec2-revoke $CLUSTER -o $CLUSTER_MASTER -u $AWS_ACCOUNT_ID || true
+  fi
   echo "Deleting group $CLUSTER_MASTER"
-  ec2-revoke $CLUSTER_MASTER -o $CLUSTER -u $AWS_ACCOUNT_ID
+  ec2-delete-group $CLUSTER_MASTER
 fi
 
-ec2-describe-group | egrep "[[:space:]]$CLUSTER[[:space:]]" > /dev/null
-if [ $? -eq 0 ]; then
+if ec2-describe-group $CLUSTER > /dev/null 2>&1; then
   echo "Deleting group $CLUSTER"
-  ec2-revoke $CLUSTER -o $CLUSTER_MASTER -u $AWS_ACCOUNT_ID
+  ec2-delete-group $CLUSTER
 fi
-
-ec2-delete-group $CLUSTER_MASTER
-ec2-delete-group $CLUSTER
diff --git a/src/contrib/ec2/bin/hadoop-ec2 b/src/contrib/ec2/bin/hadoop-ec2
index ca035a475a..be857f8118 100644
--- a/src/contrib/ec2/bin/hadoop-ec2
+++ b/src/contrib/ec2/bin/hadoop-ec2
@@ -15,6 +15,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+set -o errexit
+
 bin=`dirname "$0"`
 bin=`cd "$bin"; pwd`
 
diff --git a/src/contrib/ec2/bin/launch-hadoop-cluster b/src/contrib/ec2/bin/launch-hadoop-cluster
index a69d53eba1..f1aefc4e8c 100644
--- a/src/contrib/ec2/bin/launch-hadoop-cluster
+++ b/src/contrib/ec2/bin/launch-hadoop-cluster
@@ -17,6 +17,8 @@
 
 # Launch an EC2 cluster of Hadoop instances.
 
+set -o errexit
+
 # Import variables
 bin=`dirname "$0"`
 bin=`cd "$bin"; pwd`
diff --git a/src/contrib/ec2/bin/launch-hadoop-master b/src/contrib/ec2/bin/launch-hadoop-master
index c6621fbf58..01b9724f6e 100644
--- a/src/contrib/ec2/bin/launch-hadoop-master
+++ b/src/contrib/ec2/bin/launch-hadoop-master
@@ -17,6 +17,8 @@
 
 # Launch an EC2 Hadoop master.
 
+set -o errexit
+
 if [ -z $1 ]; then
   echo "Cluster name required!"
   exit -1
@@ -46,8 +48,7 @@ if [ ! -z "$MASTER_EC2_HOST" ]; then
   exit 0
 fi
 
-ec2-describe-group | egrep "[[:space:]]$CLUSTER_MASTER[[:space:]]" > /dev/null
-if [ ! $? -eq 0 ]; then
+if ! ec2-describe-group $CLUSTER_MASTER > /dev/null 2>&1; then
   echo "Creating group $CLUSTER_MASTER"
   ec2-add-group $CLUSTER_MASTER -d "Group for Hadoop Master."
   ec2-authorize $CLUSTER_MASTER -o $CLUSTER_MASTER -u $AWS_ACCOUNT_ID
@@ -61,8 +62,7 @@ if [ ! $? -eq 0 ]; then
   fi
 fi
 
-ec2-describe-group | egrep "[[:space:]]$CLUSTER[[:space:]]" > /dev/null
-if [ ! $? -eq 0 ]; then
+if ! ec2-describe-group $CLUSTER > /dev/null 2>&1; then
   echo "Creating group $CLUSTER"
   ec2-add-group $CLUSTER -d "Group for Hadoop Slaves."
   ec2-authorize $CLUSTER -o $CLUSTER -u $AWS_ACCOUNT_ID
@@ -105,8 +105,7 @@ MASTER_EC2_ZONE=`ec2-describe-instances $INSTANCE | grep INSTANCE | grep running
 echo $MASTER_EC2_ZONE > $MASTER_ZONE_PATH
 
 while true; do
-  REPLY=`ssh $SSH_OPTS "root@$MASTER_EC2_HOST" 'echo "hello"'`
-  if [ ! -z $REPLY ]; then
+  if ssh $SSH_OPTS "root@$MASTER_EC2_HOST" 'echo "hello"' > /dev/null 2>&1; then
    break;
   fi
   sleep 5
diff --git a/src/contrib/ec2/bin/launch-hadoop-slaves b/src/contrib/ec2/bin/launch-hadoop-slaves
index b40c1d7996..503e57f94e 100644
--- a/src/contrib/ec2/bin/launch-hadoop-slaves
+++ b/src/contrib/ec2/bin/launch-hadoop-slaves
@@ -17,6 +17,8 @@
 
 # Launch an EC2 Hadoop slaves.
 
+set -o errexit
+
 if [ -z $1 ]; then
   echo "Cluster name required!"
   exit -1
diff --git a/src/contrib/ec2/bin/list-hadoop-clusters b/src/contrib/ec2/bin/list-hadoop-clusters
index 6163f9cca6..422e4d0c35 100644
--- a/src/contrib/ec2/bin/list-hadoop-clusters
+++ b/src/contrib/ec2/bin/list-hadoop-clusters
@@ -17,6 +17,8 @@
 
 # List running clusters.
 
+set -o errexit
+
 # Import variables
 bin=`dirname "$0"`
 bin=`cd "$bin"; pwd`
diff --git a/src/contrib/ec2/bin/terminate-hadoop-cluster b/src/contrib/ec2/bin/terminate-hadoop-cluster
index 835269186d..ff20cfec01 100755
--- a/src/contrib/ec2/bin/terminate-hadoop-cluster
+++ b/src/contrib/ec2/bin/terminate-hadoop-cluster
@@ -17,6 +17,8 @@
 
 # Terminate a cluster.
 
+set -o errexit
+
 if [ -z $1 ]; then
   echo "Cluster name required!"
   exit -1