I'm creating a simple App in which the user can record and play Television Shows with Seasons and Episodes based on a pre-existing system of folders already present on the user computer.
I would like to monitor if there are any changes to the actual files/folders so I want to store an instance of FileSystemWatcher in every season to listen for any changes that might occur in the corresponding folder. Depending on how many Seasons on each of the Shows, this can reach up to 1000s events listening in the same time. Are there are any performance/instability issues I should be aware?
One of the answers here suggests that cranking up the number of listeners up to the 10,000s is definitely a problem, but since I'm not expecting that many records I might go with this answer here saying that the performance hit of events in general is not that huge. Is there some kind of rule of thumb as to how many listeners should be active in the same time? Any piece of advice is most appreciated.
OP
so I want to store an instance of FileSystemWatcher in every season to listen for any changes that might occur in the corresponding folder
You could do that but why have multiple when you can have just one:
You can watch for changes in files and subdirectories of the specified directory - MSDN
e.g.
myMonitor.IncludeSubdirectories = true;
OP
Are there are any performance/instability issues I should be aware?
Possibly, but if you use just one it reduces the possiblity without reducing functionality.
Anyway, the problem isn't so much the number of listeners (well it is but the other page goes into that) rather that the FSW can't guarentee it will not miss events during high-volume disk activity:
MSDN:
The Windows operating system notifies your component of file changes in a buffer created by the FileSystemWatcher. If there are many changes in a short time, the buffer can overflow. This causes the component to lose track of changes in the directory, and it will only provide blanket notification. Increasing the size of the buffer with the InternalBufferSize property is expensive, as it comes from non-paged memory that cannot be swapped out to disk, so keep the buffer as small yet large enough to not miss any file change events. To avoid a buffer overflow, use the NotifyFilter and IncludeSubdirectories properties so you can filter out unwanted change notifications. Tell me more