100% CPU usage on Scalability Server

Products

CA Client Automation - Asset Management CA Client Automation - IT Client Manager CA Client Automation CA Client Automation - Software Delivery CA Client Automation - Remote Control CA Client Automation - Asset Intelligence CA Client Automation - Desktop Migration Manager CA Client Automation - Patch Manager

Issue/Introduction

The following CA Client Automation processes on Scalability Server are showing a high CPU load, that causes 100% CPU Utilization:

Sector Server (amrss.exe)

Software Delivery Server (sd_server.exe)

Scalability Server (cserver.exe)

Common Configuration Agent (ccnfAgent.exe)

Environment

Release : All versions

Component : DESKTOP AND SERVER MANAGEMENT

Cause

There are a lot of Agents connected to the Scalability Server at the same time with following Configuration:

Agent is member of an Active Directory Domain E.G. (contoso.com)
Active LAN connection with assigned IPv4 address through DHCP
Active Wireless WAN connection with assigned IPv4/IPv6-Address through the Service Provider. For privacy purposes, Windows uses a temporary generated IPv6-Address to communicate with the internet (IPv6 Privacy Extensions). In the default settings, this IPv6-Address is valid only one day:

Mobile broadband adapter mobile radio:

Connection-specific DNS suffix:

Description . . . . . . . . . . . : HP lt4120 Snapdragon X5 LTE

Physical address. . . . . . . . . : AA-BB-CC-DD-EE-FF

DHCP activated. . . . . . . . . . : No.

Auto configuration activated. . . : Yes

IPv6 address. . . . . . . . . . . : xxxx: xx: xxxx: xxxx: xxxx: xxxx: xxxx: 51c7 (preferred)

Temporary IPv6 address. . . . . . : 2a00: 20: a03b: ed95: 652c: a8d: ac1e: cfa9 (preferred)

IPv6 address. . . . . . . . . . . : xxxx: xx: xxxx: xxxx: xxxx: xxxx: xxxx: 39a2 (provisional)

Connection-local IPv6 address . . : xxxx :: xxxx: xxxx: xxxx: 51c7% 14 (preferred)

IPv4 address. . . . . . . . . . . : x.x.x.32 (preferred)

Subnet mask. . . . . . . . . . . : x.x.x.192

Standard gateway. . . . . . . . . : xxxx: xx: xxxx: xxxx: xxx: xxxx: xxx: 3305

xxxx :: xxx: xxxx: xxx: 3305% 14

x.x.x.33

DHCPv6 IAID . . . . . . . . . . . : xxxxxxxx

DHCPv6 client DUID. . . . . . . . : xx-xx-xx-xx-xx-xx-xx-xx-xx-xx-xx-xx-xx-2E

DNS server. . . . . . . . . . . . : x: x: x: x :: 53

x: x: x: x :: 153

x.x.x.126

x.x.x.125

NetBIOS over TCP/IP . . . . . . . : Activated

Microsoft Windows tries to register it’s IP addresses for the network adapter in DNS using the primary DNS suffix of the clients , is for example, contoso.com (assigned to the domain join). The DNS Server assigned to the Wireless WAN adapter does not own the DNS zone contoso.com so the registering of the IP addresses in DNS will fail:

Protocol name: System

Source: Microsoft Windows DNS client

Date: May 18, 2020 6:05:36 PM

Event ID: 8015

Task category: (1028)

Level: warning

Keywords:

User: network service

Computer: CLW10.contoso.com

Description:

Failed to register host resource records (A or AAAA) for the network adapter with the following settings:

Adapter name: {A28005A0-F145-4A4D-9FD2-E0331325CA90}

Host name: CLW10

Primary domain suffix: contoso.com

DNS server list:

x: x: x: x :: 53, x: x: x: x :: 153, x.x.x.126, x.x.x.125

Sent update to Server: <?>

IP address(es):

xxxx: xx: xxxx: xxxx: xxxx: xxxx: xxxx: 51c7, xxxx: xx: xxxx: xxxx: xxxx: xxxx: xxxx: 39a2, x.x.x.32

The reason the system could not register these RRs was because the update request it sent to the DNS server timed out. The most likely cause of this is that the DNS server authoritative for the name it was attempting to register or update is not running at this time.

You can manually retry DNS registration of the network adapter and its settings by typing 'ipconfig /registerdns' at the command prompt. If problems still persist, contact your DNS server or network systems administrator.

The error in the registration of the IP addresses causes a complete renewal of the IP configuration for the Wireless WAN adapter. Among other things, this causes the temporary IPv6 address to be recreated.

This causes CAF to send a re-registration message from the Agent to the Scalability Server. This is done by CAF when the IP address list changes so it can notify the new IP address to the Scalability Server or look for a different one if the Location Awareness configuration policy is used.

Resolution

Deactivate the check box Register this connection's addresses in DNS in the Network Configuration Panel of the WWAN-Adapter:

Open Control Panel
Select Network and Internet
Select Network and Sharing Center
Click to Change Adapter Setting
Right click to the WWAN-Adapter and click to Properties
Double-click Internet Protocol Version 6 (TCP/IPv6)
Click on Button Advanced…
In tab DNS uncheck Register this connection’s addresses in DNS