Will file locking work across all OS and filesystem combinations reliably? Wondering about Windows/exFAT and Unix/NFS shares....
Another way is to use *.pid files to hold the server process id or something like *.rmi or *.jmx files to denote the ports that servers are listening on. Maybe building something into the Felix shell to track instances would be another solution? -Donald On 8/17/10 9:37 PM, Delos wrote: > > 2010/8/17 Delos <dait...@gmail.com <mailto:dait...@gmail.com>> > > > For some reasons, we often need to know if there is a running server > instance. By establishing a connection to a specific port such as > 1099, we may get the status of server. However, the method doesn't > work if default port number is changed, especially in > multi-instances scenario. In multi-instances scenario, we hope to > know if any instance is running. > > Below is my thoughts about the solution. Any comments or > suggestions, please feel free to tell me. It will be appreciated if > any better solution could be provided. > > Possible solution: > > We may create flag file for each instance and lock the file with > FileChannel.lock() when a server instance is starting up. It will > be unlocked and deleted when the server is stopped. Unlocking will > be automatically done when JVM exits; deleting the file can be done > in shutdown hook in FrameworkLauncher.launch(). > > In this way, if any flag file has been locked, we may deduce that > there is at least one running server instance; if no locked files > found, we may think all server instances are stopped. We can put all > the flag files in a same directory for us to track. > > -- > Best Regards, > > Delos > > > > > -- > Best Regards, > > Delos
