Resolution:
When you see in your engine logs, the following entry

    "[Warning: java.net.ConnectException: Connection refused,]"

it could be related to the downloading of the job information from example:

    "http://127.0.0.1:port/ds-[.....]/job.tasklet"

with the following configuration: Your engine and your driver will be on different machines. This usually occurrs because when the machine's host file is misconfigured, or the machine OS is not configure to resolve the IP from the right source.

To resolve the issue, follows those steps:

   1. Check hosts file on Unix: /etc/hosts and on Windows, c:windowssystem32driversetchosts
   2. Check for a line like 127.0.0.1
   3. If the previous entry exists, contact your System Administrator to fix the file. Usually, you want to see the following entries:
         1. 127.0.0.1 localhost
   4. For Unix, have your System Administrator check the file /etc/nsswitch.conf and make sure the "hosts:" entry is resolving through the correct method. In most cases, it should resolve first to dns and then to files. In the file you should see "hosts: dns files".

Note: GridServer relies on the OS call to resolve the hostname into IP address(es).

GridServer ConnectException due to localhost IP