KBI 311760 New Feature: Enhanced Argent Queue Engine Checking For AWS/Azure

Version

Argent Job Scheduler 1906-A and above

Date

Saturday, 22 June 2019

Summary

Argent Scheduling Engine override ping to check Argent Queue Engine Status

Technical Background

In Argent Job Scheduler versions 1902-A and below, ICMP ping was used to check if an Argent Queue Engine was online.

In AWS and Azure cloud, by default, all servers have the ICMP service disabled and so a ping will fail

Thus even if the Argent Queue Engine server is up and running fine, the Scheduling Engine will wrongly mark the Argent Queue Engine server as offline and no Jobs will be submitted to this Argent Queue Engine

Argent Scheduling Engine has been enhanced to check Argent Queue Engine status through a TCP/IP port (soft; default is 3000)

So, instead of using a ping to check if a Queue Engine is online, the central Scheduling Engine will now use a connection to the Queue Engine port

If connection to the port can be successfully made, the Argent Queue Engine server will be marked as online

If the connection to Argent Queue Engine port fails, then – and only then – will a ping be tried

If this ping succeeds (after the port test fails) this means either the Argent Queue Engine service is not running, or is blocked by a firewall, or both

If the ping fails, either the Argent Queue Engine server is down or ICMP is disabled in the Argent Queue Engine server

Resolution

Upgrade to Argent Job Scheduler 1906-A or above