Konstantin Knizhnik 82a4777046 Add local free space monitor (#3832) ...

## Describe your changes

Monitor free spae in local file system and shrink local file cache size
if it is under watermark.
Neon is using local storage for temp files (temp table + intermediate
results), unlogged relations
and local file cache.

Ideally all space not used for temporary files should be used for local
file cache.
Temporary files and even unlogged relation are intended to have small
life time (because
them can be lost at  any moment in case of compute restart).

So the policy is to overcommit local cache size and shrink it if there
is not enough free space.
As far as temporary files are expected to be needed for a short time,
there i no need
to permanently shrink local file cache size. Instead of it, we just
throw away least recently accessed elements
from local file cache, releasing some space on the local disk.

## Issue ticket number and link

## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.

---------

Co-authored-by: sharnoff <sharnoff@neon.tech>

2023-03-28 08:27:50 +03:00

..

neon

Add local free space monitor (#3832)

2023-03-28 08:27:50 +03:00

neon_test_utils

Rename old project name references

2022-09-14 08:14:05 +03:00

neon_utils

Be able to get number of CPUs (#3774)

2023-03-10 19:00:20 +02:00

neon_walredo

Make postgres --wal-redo more embeddable.

2023-03-07 15:01:14 +02:00

typedefs.list

Refotmat pgxn code, add typedefs.list that was used

2022-09-14 08:14:05 +03:00