Kbase P118900: WebClient application hangs or displays error when using AIA
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
16/10/2008 |
|
Status: Unverified
FACT(s) (Environment):
Progress 9.x
OpenEdge 10.x
WebClient
SYMPTOM(s):
WebClient application hangs when using AIA
WebClient application reports disconnection from server
Issue appears after application has been working properly for a while
AIA or web server reports that connection was terminated by client
HTTP client-to-server connections are automatically terminated by network operator when idle
CAUSE:
When possible, the WebClient application tries to use a persistent connection to the server for requests to the AIA. This persistent connection is negotiated at the first connection to the server, depending on the availability of the HTTP Keep-Alive feature on the web server. If the server advertises this feature and a persistent connection is established, then it is expected to hold until the client terminates the connection.
If the network forcefully closes a persistent connection established that way, then it creates an unexpected condition in the client application and the application can start to behave inconsistently. The most common symptom is hanging.
FIX:
The primary solution to this issue is to ensure that the network honors the persistent state of connections.
Under some circumstances, this cannot be ensured. In this case, the secondary solution is to prevent the negotiation of persistent connections altogether, by disabling the HTTP Keep-Alive feature on the web server. This can be done in several ways:
- for servers which allow to configure this feature directly, just disable the Keep-Alive feature.
- otherwise, force the use of the HTTP/1.0 protocol on the web server. HTTP/1.0 does not support Keep-Alive.