Internal web server on http://localhost:8080 (Windows) no longer responding

cwt237

I installed LightStreamer last week and it worked out of the box with the demos that are part of the package (only configuration needed was setting the pointer to the Java runtime).

After working with it for some time the local web server has stopped working at http://localhost:8080

I have tried changing the port to something else (e.g. to 8081 and restarting the server) - without luck.

I have tried stopping the server and restarting it - and installing it as a Windows service. The service runs - and the log file does not report any problems - and even the .NET adapters can connect via remoting to the server (e.g. localhost on port 6661), but the local webserver is still not running.

Running the server using the .\bin\windows\Start_LS_as_Application.bat also works and no problems are reported by the webserver still does not work.

Is there any way to debug this issue? I have had no luck looking in log files, since nothing is reported about the webserver.

Giuseppe Corti

The isuue that you describe is actually quite strange. The first step we can take is raise the log level of these 3 categories (you find them in the LS_HOME/conf/lightstreamer_log_conf.xml):

<logger name="LightstreamerLogger.connections" level="DEBUG"/>
<logger name="LightstreamerLogger.connections.http" level="DEBUG">
<logger name="LightstreamerLogger.webServer" level="DEBUG"/>

Please restart the server and test the welcome page (http://localhost:8080/).
Then take a look in the server log for more info (in the case please post here some relevant snippets).

cwt237

cwt237

It doesn't even report anything about the webserver.

The only thing that I can see "might" be a problem is:

18-Sep-13 10:23:20,987|INFO |LightstreamerLogger.external |Thread-2 |Could not connect to external service to check for software updates. Please check proxy settings in lightstreamer_version_conf.xml.

Giuseppe Corti

The log that you posted shows that the Lightstreamer Server startup procedure has never finished. Indeed it is waiting for Remote Metadata Adapter connections.
Please note that in case of Remote Metadata Adapters the server is blocked waiting for the connections, even in the case you are using the "robust" version unless in the file "adapters.xml" is present this configuration

<param name="first_connection_timeout_millis">10000</param>

that sets a timeout after which the startup procedure continues anyway.

So to solve your problem, if you do not intend to use the Remote Adapters anymore, please remove them from the folder "LS_HOME/adapters", otherwise if you want the Lightstreamer server (including the internal Web Server) starts even before all Remote Adapters are connected sets the <first_connection_timeout_millis> parameter in the <metadata_provider> section of "adapters.xml" configuration files.

I confirm you the message concerning external services does not affect in any way the regular operation of Lightstreamer server.

cwt237

Ok, it seems there is a problem with my .NET adapters (probably the metadata adapters). They are never loaded fully (log is not reporting "Finished loading metadata adapter XXX").

If I remove them it works fine, so there is a problem with them apparently. I will investigate further into that.

cwt237

Just read the reply - I will try that.

Thanks!

cwt237

That works like a charm.

I had no idea that the timeout configuration was needed.

Thanks! :Smile_Ad:

Giuseppe Corti

[SYNTAX=xml][/SYNTAX]Indeed the <param name="first_connection_timeout_millis"> parameter is not mandatory for the <metadata_provider> section.
But its default value is -1, which means endless waiting. This is because, in normal cases, is not convenient to proceed with the initialization of the server before the Metadata Adapter is properly connected.

Please refer to the auto-documented "adapters.xml" template in "LS_HOME/DOCS-SDKs/sdk_adapter_remoting_infrastructure/conf/sockets(robust)".

 <!-- Optional, specific for RobustNetworkedMetadataProvider.
             The timeout for the first connection attempt. Upon the Proxy Adapter
             initialization at Lightstreamer Server startup, if a remote server
             is not available, Lightstreamer Server startup can be delayed until
             this timeout expires.
             A negative value stands for an unlimited timeout.
             Note that, as soon as Lightstreamer Server startup completes,
             as long as a connection to a remote server is still missing,
             all client requests will be refused.
             Default: -1. -->
        <param name="first_connection_timeout_millis">10000</param>

cwt237

Yep, ok.

In my case the .NET adapter is implemented using a very simple scheme for connecting to the Lighstreamer server (based on your example with establishing TCP connections to specific ports inside a console process). It is kind of the "chicken and egg" problem. The LS process must be running for the adapter to connect - but the adapter must be running for the LS startup to complete.

However, running the adapter first - and implementing retry logic (to set up the communication channels), e.g. detecting when LS server is available, should fix that problem.

For now, I have just added the timeout and that works fine.