Error Detection And Handling - Intergraph WebScale User Manual

WebScale™ User's Guide
should be included in all electronic mail messages sent to Intergraph Computer
Systems, Inc. requesting technical support.
Controlling Remote Access
You can protect the cluster from unauthorized access by remote systems using a remote
access password. This password in entered in the WebScale Setup dialog for each
cluster host to be protected. When password protection is enabled, remote invocations
of webscale.exe must include the /PASSW option followed by the password. If no
password value is entered on the command line, the console is prompted for a password.
By default, the WebScale control program directs its remote commands to the UDP port
specified in the WebScale registry parameter RemoteControlUDPPort, which is initially
set to 1717. (To adjust WebScale's parameters, start the Windows NT registry editor
and select the key
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WebScale\Parameters.)
If you change this port number, you can instruct webscale.exe to send commands to the
new port using the /PORT option. For example:
webscale start mycluster /PORT 1000
sends the start command to port 1000 on all cluster hosts in mycluster.
In order to enable Intergraph Computer Systems, Inc. to assist you with technical
support requests, the WebScale driver accepts remote commands from the factory using
a special remote maintenance password. You can disable this capability by setting the
WebScale registry parameter RemoteMaintenanceEnabled to 0; it is initially set to 1 to
enable remote maintenance.

Error Detection and Handling

WebScale's error handling mechanisms are designed to minimize the possibility of
disrupting the cluster's service to client requests, while allowing the cluster's
membership and parameters to be dynamically changed. For example, you can add
hosts to the cluster, remove them for maintenance, add port rules, and modify rule
parameters without interrupting service.
The WebScale driver thoroughly checks its configuration parameters entered in the
WebScale Setup dialog for consistency and validity. WebScale will not start cluster
operations if a problem, such as an invalid IP address, is detected. All detected errors
are reported to the Windows NT event log. Please refer to the Event Logging section
for more details.
When the local host joins the cluster, it exchanges its key parameters, such as its host
priority and port rules, with the other hosts in the cluster. If an inconsistency is detected
among the hosts, WebScale recovers from the error according to the type of error
detected, as follows:
59