cache_loader

[kokins]

It's more a question than bug.

As far as I get ANGIE after restart drops all information from cache_manager about files and their inactivity and loads all information from the disk. I didn't find any evidence that ANGIE use atime FS file attribute to recover inactivity, but it could be useful for more precise work.

Am I wrong ? I'm not advanced in C, I could miss something.

[VBart]

There are multiple issues with atimes, notably:

1. They may not be updated at all if FS is mounted with relatime/noatime option (which is quite common and recommended optimization practice). And I'm not sure that enabling atime actually worth it.

2. Update of atime happens on reading every byte from file, while inactivity period is calculated from the request access time. Those times can be significantly different.

[kokins]

Thank you for the fast reply.

Perhaps you can advise something on what is best to do in the case when restart is needed and the cache is filled more than 60%. Because the lost of inactivity(activity) info leads inevitably to full cache for some time.

Purge or delete all cache before restart?

[VBart]

If you don't care much about preserving cache, then purging it can be a good solution. Also you may try to tune cache loader parameters in order to shorten cache loading time.

[kokins]

If you don't care much about preserving cache, then purging it can be a good solution. Also you may try to tune cache loader parameters in order to shorten cache loading time.

Ok. Thanks for the recommendation.

But anyway I would recommend to reestimate approach when you can gather atime information from FS at least for first launch maybe with some option.

[VBart]

Anyway, it doesn't help if the cache loader process takes significant time to load the cache. Cache files, that hasn't been processed by the cache loader will be still there and consume space.