Book Image

Troubleshooting NetScaler

By : Raghu Varma Tirumalaraju
Book Image

Troubleshooting NetScaler

By: Raghu Varma Tirumalaraju

Overview of this book

NetScaler is a high performance Application Delivery Controller (ADC). Making the most of it requires knowledge that straddles the application and networking worlds. As an ADC owner you will also likely be the first person to be solicited when your business applications fail. You will need to be quick in identifying if the problem is with the application, the server, the network, or NetScaler itself. This book provides you with the vital troubleshooting knowledge needed to act fast when issues happen. It gives you a thorough understanding of the NetScaler layout, how it integrates with the network, and what issues to expect when working with the traffic management, authentication, NetScaler Gateway and application firewall features. We will also look at what information to seek out in the logs, how to use tracing, and explore utilities that exist on NetScaler to help you find the root cause of your issues.
Table of Contents (17 chapters)
Troubleshooting NetScaler
Credits
Notice
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

CPU and memory issues


Most high CPU and memory issues will require working with tech support to conclude the root cause through adequate code-level analysis. There are, however, actions you can take, including collecting useful information, both to speed up the investigation, but also to avoid having to wait for the issue to recur for that information to be captured.

Types of NetScaler CPU

NetScaler has two CPUs that do very different things:

  • The Management CPU handles mainly bookkeeping tasks and parts of the NetScaler code that run in FreeBSD, such as the various protocol daemons (for example, snmpd). A high management CPU usage, unless prolonged, does not impact packet handling, and a momentary spike should be expected when logs are compressed as part of a rollover.

  • The Packet Engine CPU is entirely dedicated to handling packets, therefore, a saturation of this CPU can impact your production traffic and needs to be dealt with immediately.

SNMP is the best way to detect high CPU events as it...