Kbase 21079: Blank Page Encountered With Webspeed
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/16/2008 |
|
SUMMARY:
This Knowledge Base Solution gives some reasons why a 'blank page' might be displayed when running WebSpeed applications.
When loading a new page or refreshing an existing page, you might
encounter a 'blank page' with no error messages being reported to the screen (via the browser) or log files. When reviewing source code for the blank page, you see the following:
<!-- Generated by WebSpeed - http://www.WebSpeed.com/ -->
EXPLANATION:
In most cases, you will find that the request cannot be fulfilled by the initial agent because communication between the messenger and agent has been broken. By reloading the page, a new agent handles and finishes off the request.
Why is the request broken?
One possible reason could be the code. By default, WebSpeed waits 10
seconds for a locked record. To increase or specify a different "lock
wait timeout", the -lkwtmo startup option can be used with the
WebSpeed agent. (See Progress Knowledge Base Solution 16073 for more information on this parameter). However, this parameter is not a solution to any fundamental design problems that may exist within the code. A better technique for managing lock conflicts is to use the NO-WAIT and NO-ERROR options with EXCLUSIVE-LOCK on the record.
The second possible reason could be timeout properties not configured
correctly within the Web server. These timeout properties can involve the Web server alone or a specific messenger timeout setting as well.
Review all specific settings on the Web server to ensure that all
timeout values are set appropriately. On Netscape, some values may
need to be added into the magnus.conf file, because these values cannot be seen within the Netscape AdminServer Utility.
Be cautious of the fact that within some Web servers, iPlanet for instance, the CGI engine creates CGIStub processes as needed to handle CGI processes. On systems that serve a large load and rely heavily on CGI-generated content, it is possible for the spawned CGIStub processes to consume the entire system. If this is happening on your server, the CGIStub processes can be tuned to restrict how many new CGIStub processes can be spawned, their timeout value, and the minimum number of CGIStub processes.
http://home.netscape.com/eng/server/webserver/4.0/tuning/
perf.htm#1012571
Note that, when SSL is enabled, Netscape Web server will set the
default TIMEOUT value of zero, hence this value must be set
accordingly. This implementation may be specific to iPlanet.
http://home.netscape.com/eng/server/webserver/4.0/tuning/perf.htm
SSL TUNNELING timeout switches should also be reviewed and set appropriately on some Web servers.
References to Written Documentation:
Progress Knowledge Base Solution 16073, "Lock Time Out Parameter in V8.1 -lkwtmo Lock Wait Timeout"