I wouldn't copy files around... that'd take up far to much space and time, if the log files are big — log files usually are.

A second problem is in file caching: the webserver might refuse to serve up the new file, even after it has been updated, if it delivered the "same" document somewhat earlier. A server like Apache acts as if it has a in-memory file cache. I think it must have.

A simple, fine working solution for the latter is to serve up the logs dynamically, using a script, even if all it does is just read the contents of a file and pass them along to the browser.

So... If we're already using a script to show the logs... Why not filter the existing logs while displaying them? I'm thinking of a way to timestamp the actions, and simply skipping the actions in the log that are too recent. For example, Apache's server logs include a timestamp per line.

Under the assumption that the log gets appended to, as is commonly the case, and there is no such thing as a timestamp in the data, you can save the current time and log file length whenever an event occurs, in a separate index file. That way, you can figure out where to stop reading the log, based on what tell tells you. Anything beyond that threshold is more recent.

In reply to Re: File playback with lag by bart
in thread File playback with lag by ecuguru

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