Windows: EBUSY: resource busy or locked

I’m setting up logdna-agent on a Windows machine for a log file that is continuously written to. The program will often open the file and write to it. The writing causes a lock which interferes with reading the file’s contents.

Unfortunately this leads to logdna-agent failing with the error "0700 [error] tail error: [FILE]: Error: EBUSY: resource busy or locked, open '[FILE]'.

I can replicate this in PowerShell using Get-Content [FILE] -Wait. This will stream contents until the program generating the log locks the file, causing the PowerShell command to fail.

I would expect logdna-agent to not throw an error when the file is locked and instead wait until the file isn’t locked and the contents can be read.

[summatix]

The error seems to be getting thrown here: https://github.com/logdna/logdna-agent/blob/master/lib/file-utilities.js#L134

I believe what is happening is that the program is actually erasing all previous contents of the log and then writing to the same file again.

[darinspivey]

Hey guys, sorry this is a late reply, but we’re doing some re-organization of this project and addressing some bugs. On that note, we have completely re-written the existing “tail” logic to be a lossless, fault tolerant implementation. Stay tuned soon for the announcement of what will be called @logdna/tail-file (we are open sourcing this solution for the public).

For now, in an effort to clean up these issues before doing some re-organizing, I’m going to go ahead and close this, but we certainly appreciate the discussion around this. If this is still a problem with the new implementation, the suggested fix to tolerate EBUSY can be easily implemented.