--- Begin Message ---
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Subject: |
[PATCH] substitute: Delete cached narinfos more than two-month old. |
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Date: |
Wed, 31 May 2023 23:22:01 +0200 |
This allows 'guix substitute' to shrink the cache a bit more, which
saves space and improves performance of cache-cleanup phases since fewer
entries need to be traversed.
* guix/scripts/substitute.scm (cached-narinfo-expiration-time): Define
'max-ttl' and use it as an upper bound.
---
guix/scripts/substitute.scm | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
Hi!
You might have noticed that /var/guix/substitute/cache tends to grow.
On my laptop I have:
--8<---------------cut here---------------start------------->8---
$ du -hs /var/guix/substitute/cache/
152M /var/guix/substitute/cache/
$ du /var/guix/substitute/cache/ |sort -k1 -n
[...]
16196
/var/guix/substitute/cache/kzwjeblndsbkjzmjailrt4bnhguil7tqjmewzcyw22hgajbhfy3q
136216
/var/guix/substitute/cache/4refhwxbjmeua2kwg2nmzhv4dg4d3dorpjefq7kiciw2pfhaf26a
155364 /var/guix/substitute/cache/
--8<---------------cut here---------------end--------------->8---
This full of old entries that I’m unlikely to need:
--8<---------------cut here---------------start------------->8---
$ ls -lt
/var/guix/substitute/cache/4refhwxbjmeua2kwg2nmzhv4dg4d3dorpjefq7kiciw2pfhaf26a
|tail -10
-rw------- 1 root root 1187 Nov 30 18:49 xlxgm0lzg25fsz99qql8wp8y4l0ijvy6
-rw------- 1 root root 3182 Nov 30 18:49 yqdklfzzxx2zm2vvx11pm5my2jzlzwmy
-rw------- 1 root root 1180 Nov 30 18:49 18pzv1gjw9mi3bzkvb2ms9am37kd960i
-rw------- 1 root root 1484 Nov 30 18:49 qqpc6n1q5jz29zzwf1jn8srq3a5ysy86
-rw------- 1 root root 1060 Nov 30 18:27 9r6w8hrw2bpm2sjp03ynl1aifjkcn9wi
-rw------- 1 root root 1056 Nov 30 18:27 ghdwy0xa2h9xi5qh2picb19fhhk0fzhp
-rw------- 1 root root 2108 Nov 30 18:27 ixp9xd4cbs774yh5qkvywmjk1606s8i8
-rw------- 1 root root 1052 Nov 30 18:27 laawrywlbx1y76sdribiw8aygcvadili
-rw------- 1 root root 1092 Nov 30 18:27 m72pfbhqhbhi7gj8kvy66lr99v7hvk7z
-rw------- 1 root root 1070 Nov 30 18:27 ym69k8mzmxbw1ar76nzghl38h4g7g8v4
--8<---------------cut here---------------end--------------->8---
That six-month old because that’s the TTL and ci.guix.gnu.org has been
advertising for some time now.
Long story short: we’d rather trim the cache more aggressively.
Thoughts?
Ludo’.
diff --git a/guix/scripts/substitute.scm b/guix/scripts/substitute.scm
index 3626832dda..92935268b3 100755
--- a/guix/scripts/substitute.scm
+++ b/guix/scripts/substitute.scm
@@ -167,6 +167,12 @@ (define (lookup-narinfo caches path authorized?)
(define (cached-narinfo-expiration-time file)
"Return the expiration time for FILE, which is a cached narinfo."
+ (define max-ttl
+ ;; Higher bound on the TTL used to avoid keeping around cached narinfos
+ ;; for too long, which makes the cache bigger and more expensive to
+ ;; traverse.
+ (* 2 30 24 60 60)) ;2 months
+
(catch 'system-error
(lambda ()
(call-with-input-file file
@@ -174,10 +180,10 @@ (define (cached-narinfo-expiration-time file)
(match (read port)
(('narinfo ('version 2) ('cache-uri uri)
('date date) ('ttl ttl) ('value #f))
- (+ date ttl))
+ (+ date (min ttl max-ttl)))
(('narinfo ('version 2) ('cache-uri uri)
('date date) ('ttl ttl) ('value value))
- (+ date ttl))
+ (+ date (min ttl max-ttl)))
(x
0)))))
(lambda args
base-commit: 77f52db416a13e195d090cad4e9e7658feb2e86b
--
2.40.1
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: bug#63817: [PATCH] substitute: Delete cached narinfos more than two-month old. |
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Date: |
Thu, 08 Jun 2023 23:49:50 +0200 |
|
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) |
Ludovic Courtès <ludo@gnu.org> skribis:
> This allows 'guix substitute' to shrink the cache a bit more, which
> saves space and improves performance of cache-cleanup phases since fewer
> entries need to be traversed.
>
> * guix/scripts/substitute.scm (cached-narinfo-expiration-time): Define
> 'max-ttl' and use it as an upper bound.
Pushed as 3f5e14182931f123c10513a3e1e2abaebfb52279.
Ludo'.
--- End Message ---