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

Troubleshooting HA Failovers


HA Failover-related issues are generally considered to be very serious. There are broadly of four types:

  • HA node state issues

  • Heartbeats not being seen

  • New primary not handling traffic

  • Sync and propagation issues

Let's take a look at these one by one.

HA Node state issues

Sometimes when you do a show node, you might see the status Not UP. This means the node is not ready to process traffic, if it were to become primary. This can be because of the following reasons:

  • Critical interfaces are down

  • The SSL card is down

  • High Availability is disabled (on the remote node)

  • The unit is still booting up or rebooting

There is a very handy list of the various node states and what they mean in article CTX118519. I sourced the following tables from the article as they will greatly help with understanding what the Node state is complaining about.

Node States seen on Primary:

Value

Meaning

INIT

The appliance is initializing.

UP

The appliance is working as expected.

PARTIAL_FAIL...