Little script adapted from paramiko simle example to check all your servers one at a time for an error condition. Not necessary if your servers use private key access.

checklogs.py

# http://stackoverflow.com/questions/6012665/read-non-blocking-error-while-using-pxssh-ssh-module-for-python
# https://github.com/paramiko/paramiko/blob/master/README
# http://stackoverflow.com/questions/8491194/how-to-handle-socket-errors-as-exceptions-in-python-paramiko

import paramiko, base64, getpass, socket

client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

user = getpass.getuser()
pwd = getpass.getpass()

for i in range(1, 100):
  worker = 'server{:0>3}.prod'.format(i) # assuming format is server001, server002, server003, etc...
  try: 
    client.connect(worker, username=user, password=pwd, timeout=2)
    stdin, stdout, stderr = client.exec_command('grep -c WTFException /var/log/server.log')
    for line in stdout:
      print worker + ": " + line.strip('\n')
  except socket.error:
    print "couldn't connect to " + worker

client.close()