dcs/bin/servers.sh

#!/usr/bin/env bash
#/**
# @@@ START COPYRIGHT @@@
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
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# @@@ END COPYRIGHT @@@
# */
#
# Run a shell command on all server hosts.
#
# Environment Variables
#
#   DCS_SERVERS    File naming remote hosts.
#
# Modelled after $HADOOP_HOME/bin/slaves.sh.

usage="Usage: servers [--config <dcs-confdir>] command..."

# if no args specified, show usage
if [ $# -le 0 ]; then
  echo $usage
  exit 1
fi

bin=`dirname "${BASH_SOURCE-$0}"`
bin=`cd "$bin">/dev/null; pwd`

. "$bin"/dcs-config.sh

# If the servers file is specified in the command line,
# then it takes precedence over the definition in
# dcs-env.sh. Save it here.
HOSTLIST=$DCS_SERVERS

if [ "$HOSTLIST" = "" ]; then
  if [ "$DCS_SERVERS" = "" ]; then
    export HOSTLIST="${DCS_CONF_DIR}/servers"
  else
    export HOSTLIST="${DCS_SERVERS}"
  fi
fi

instance=1

while read server count
do
  if [ "$server" == "localhost" ] || [ "$server" == "$HOSTNAME" ] ; then
    eval $"${@// /\\ } $instance $count" 2>&1 | sed "s/^/$server: /" &
  else
    if ${DCS_SLAVE_PARALLEL:-true}; then
      ssh -q -n $DCS_SSH_OPTS $server $"${@// /\\ } $instance $count"\
        2>&1 | sed "s/^/$server: /" &
    else # run each command serially
      ssh -q -n $DCS_SSH_OPTS $server $"${@// /\\ } $instance $count" \
        2>&1 | sed "s/^/$server: /" &
    fi
  fi
  
  if [ "$DCS_SLAVE_SLEEP" != "" ]; then
    sleep $DCS_SLAVE_SLEEP
  fi
  
  let instance++

done < "$HOSTLIST"

wait