Bind-specific collocated setup on Solaris, Linux, and HP-UX
 Technote (troubleshooting)
 
Problem(Abstract)
Bind-specific collocated setup on Solaris, Linux, and HP-UX
 
Resolving the problem
The Solaris, Linux, and HP-UX operating systems do not allow a packet to leave the computer if it is destined for a locally-aliased IP address. Consequently, when the cluster IP is aliased on either operating system, the Network Dispatcher (Load Balancer) advisors target the server address directly instead of querying the cluster IP. If the server applications are binding to the cluster IP, the advisors do not receive a response; the advisors subsequently mark the server down.

On Solaris and HP-UX, an alternative setup is to use an ARP publish command to simulate aliasing the cluster IP instead of the ifconfig command. Refraining from using the ifconfig allows advisors to target the cluster address. The advisors then talk correctly to a binding server application; however, the ARP publish does not allow a local application to bind to the IP address because the address does not exist on the IP stack.

Linux does not have a proper ARP publish command, so this alternative does not work for Linux. The restrictions are:

  • Network Dispatcher on Linux does not support the use of advisors to query bind-specific applications.
  • Network Dispatcher on Solaris supports advisors against bind-specific applications if the ARP publish is used instead of ifconfig alias; however, the application cannot reside on the Dispatcher computer because it will not be able to bind.
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers WebSphere Edge Server Load Balancer Linux, Solaris Edge Server 2.0 GA, Edge Server 2.0 NLV, Edge Server 2.0 PTF1, Edge Server 2.0 PTF2
Application Servers Runtimes for Java Technology Java SDK
 
Historical Number
84590
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Edge Component
Operating system(s): Solaris
Software version: 5.0
Software edition:
Reference #: 1041848
IBM Group: Software Group
Modified date: Dec 18, 2003