Should I lock the targets file when updating it?

[Wang Yngwie]

I have a big targets file, it's about 8M size and there are more than twenty thousand targetgroups. When Prometheus scans  sd_files, my updating program might writing that file simultaneously. In that case, the Discovery process may read part of the file or encounter an error. Is it possible and should I lock the targets file while updating it?

[Brian Brazil]

On Wed, 13 Jan 2021 at 13:18, Wang Yngwie <yngwi...@gmail.com> wrote:

I have a big targets file, it's about 8M size and there are more than twenty thousand targetgroups. When Prometheus scans  sd_files, my updating program might writing that file simultaneously. In that case, the Discovery process may read part of the file or encounter an error. Is it possible and should I lock the targets file while updating it?

Don't try locking, instead build up the new file in a temporary file and then rename() when you're done. 

--

Brian Brazil

www.robustperception.io

[Julien Pivotto]

You should then create a .tmp.yml file, then move the file (rename) to
the .yml, which is an atomic operation.

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Julien Pivotto
@roidelapluie

[Wang Yngwie]

Thanks for your reply very much, it really helps. ☺

Julien Pivotto <roidel...@prometheus.io> 于2021年1月13日周三 下午9:26写道：