KB Attachments not Downloading in AWS

Products

• CA Service Management - Service Desk Manager

Issue/Introduction

After configuring an AWS load balancer in front of SDM, KB attachments are not working. 

When trying to download attachments to KBs, Browser Console mode shows the following:

jquery-3.6.0.min.js:2     Failed to load resource: the server responded with a status of 404 ()
send @ jquery-3.6.0.min.js:2

/CAisd/pdmweb.exe?SID=1809329541+FID=3755+OP=LINK_WITH_BOPSID+KEEP_ROLE=1+URL=javascript:parent.ahdframeset.downloadWin.Download(13176936,%27https://MYSERVER.COM/CAisd/UploadServlet%27,%27SERVERNAME%27,%25bopsid):1     Failed to load resource: the server responded with a status of 403 ()

jsrvr.log may display:

07/13 10:10:54.280 [TCP_port-Read:web:wsp] ERROR TCP_port 892 ReadInt Socketexception (did slump die?)java.net.SocketException: Connection reset 
07/13 10:10:55.291 [TCP_port-Read:web:local] ERROR TCP_port 892 ReadInt Socketexception (did slump die?)java.net.SocketException: Connection reset 
07/13 10:10:59.806 [TCP_port-Read:rep_daemon:MYSERVER] ERROR TCP_port 903 ReadInt EOFException (did slump die?)java.io.EOFException 
07/13 10:10:59.806 [TCP_port-Read:rep_daemon:MYSERVER] ERROR TCP_port 1322 Call to read_msg failed.java.net.SocketException 

Environment

Release : 17.3

Cause

Customers AWS WAF (Web Application Firewall) was blocking the download attempts

Resolution

Suggest involving customers AWS and Firewall teams to ensure the necessary exceptions are configured in the firewall

In a recent case simply restarting the services resolved the problem.