CA Client Automation System Delivery Engine lost connectivity with the Database Server with logs indicating 'Communication Link Failure'

Products

• CA Automation Suite for Data Centers - Configuration Automation
• CA Client Automation - Asset Management
• CA Client Automation - IT Client Manager
• CA Client Automation
• CA Client Automation - Remote Control
• CA Client Automation - Asset Intelligence
• CA Client Automation - Desktop Migration Manager
• CA Client Automation - Patch Manager

Issue/Introduction

CA Client Automation System Delivery Engine plugin stopped. 

The Windows Event log shows the following error:

Log Name: Application
Source: DSM
Date: 5/09/2018 10:02:07 p.m.
Event ID: 1000
Task Category: USD
Level: Error
Keywords: Classic
User: N/A
Computer: TESTSERVER,CA.COM
Description:
A task could not be run by Task Manager. Serious exception; name= TableError comment= [TM(L) - [005148]]:[begin]:[usd_root]:->[4750]
dbApi[0]:<-3,-19>
->[0] ADO Version 6.3 - COM Error: ErrorCode:-2147467259,WordErrorCode:0, Unspecified error, Communication link failure, Microsoft SQL Server Native Client 11.0, (null) location= [email protected]:ps_dbapi\isam_db.cxx:461 [email protected]:TaskMgr\TASKMAN.CXX:796

Environment

All versions of CA Client Automation

Resolution

The error occurs when the System Delivery Engine plugin or any of the CA Client Automation plugins are unable to access the MDB (Database server).
The error is a native SQL Communication Error. 

Ensure that there are no network connectivity issues between the CA Client Automation application server and the database server (if the database is remote).
Ensure that any activity like SQL Backup, Scheduled tasks or VMWare snapshots (if database is hosted on a virtual machine) or a similar activity is not causing any database communication issue.