Kbase P56166: Webclient Application encounters Connection Errors Intermittently. Connection failure for host port
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
8/26/2009 |
|
Status: Unverified
SYMPTOM(s):
Webclient application encounters connections errors intermittently.
Error No Servers Available ... disconnecting client. (8091)
Connection failure for host <host> port <port> transport TCP. (9407)
SERVER <name> is not connected. (5451)
Server progress.com::k7pspl-as::14665::7b95298e70bc14a5:5c8569:f896606a38:-78d0 is not connected (5451)
AppServer broker log file contains the following errors.
ERROR: No servers available. (8089)
Error No Servers Available ... disconnecting client. (8091)
Webclient Application connects to a AppServer directly via the Internet.
Port where AppServer resides has been opened on the Firewall bidirectional.
CAUSE:
You have exceeded the maximum number of AppServer servers available.
On a Stateless AppServer, this may happen when the number of simultaneous client requests is approaching the maximum number of servers available.
At any given time there may be some AppServer servers which have finished serving a client request and have disconnected from it, yet they are not back in the AVAILABLE state yet (due to some small internal latencies). When the workload on the AppServer is approaching the limit of maximum servers, this is what may happen (given that N is the maximum number of AppServer servers):
- (N - 1) AppServer servers are serving requests from (N - 1) clients. At the same time, the Nth AppServer server is going back to AVAILABLE after finishing serving a client request.
- A new client request comes in.
- The broker cannot find any available AppServer server: from its point of view all servers are busy (including the one which is going back to AVAILABLE).
- Error 8089 is generated, and the client request is refused even though only (N - 1) other clients are being served.
FIX:
Increase the maximum number of AppServer servers available.