--- Begin Message ---
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Subject: |
[PATCH] substitutes: Don't cache negative lookups or transient errors. |
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Date: |
Mon, 19 Apr 2021 19:40:36 +0100 |
Caching these responses can delay users getting substitutes, since they'll
have to wait at least as long as the cache TTL to fetch the substitute, even
if it's available sooner.
* guix/substitutes.scm (%narinfo-negative-ttl, %narinfo-transient-error-ttl):
Remove variables.
(cache-narinfo!): Adjust to not use the negative TTL.
(fetch-narinfos): Don't cache non 200 status code responses.
---
guix/substitutes.scm | 22 +++-------------------
1 file changed, 3 insertions(+), 19 deletions(-)
diff --git a/guix/substitutes.scm b/guix/substitutes.scm
index 08f8c24efd..55daa6c964 100644
--- a/guix/substitutes.scm
+++ b/guix/substitutes.scm
@@ -70,14 +70,6 @@
;; 'Cache-Control' response header.
(* 36 3600))
-(define %narinfo-negative-ttl
- ;; Likewise, but for negative lookups---i.e., cached lookup failures (404).
- (* 1 3600))
-
-(define %narinfo-transient-error-ttl
- ;; Likewise, but for transient errors such as 504 ("Gateway timeout").
- (* 10 60))
-
(define %narinfo-cache-directory
;; A local cache of narinfos, to avoid going to the network. Most of the
;; time, 'guix substitute' is called by guix-daemon as root and stores its
@@ -104,8 +96,7 @@ entry is stored in a sub-directory specific to CACHE-URL."
(define (cache-narinfo! cache-url path narinfo ttl)
"Cache locally NARNIFO for PATH, which originates from CACHE-URL, with the
-given TTL (a number of seconds or #f). NARINFO may be #f, in which case it
-indicates that PATH is unavailable at CACHE-URL."
+given TTL (a number of seconds or #f)."
(define now
(current-time time-monotonic))
@@ -113,8 +104,7 @@ indicates that PATH is unavailable at CACHE-URL."
`(narinfo (version 2)
(cache-uri ,cache-uri)
(date ,(time-second now))
- (ttl ,(or ttl
- (if narinfo %narinfo-ttl %narinfo-negative-ttl)))
+ (ttl ,(or ttl %narinfo-ttl))
(value ,(and=> narinfo narinfo->string))))
(let ((file (narinfo-cache-file cache-url path)))
@@ -214,16 +204,10 @@ if file doesn't exist, and the narinfo otherwise."
(cache-narinfo! url (narinfo-path narinfo) narinfo ttl)
(cons narinfo result))
result))
- (let* ((path (uri-path (request-uri request)))
- (hash-part (basename
- (string-drop-right path 8)))) ;drop ".narinfo"
+ (begin
(if len
(get-bytevector-n port len)
(read-to-eof port))
- (cache-narinfo! url (hash-part->path hash-part) #f
- (if (or (= 404 code) (= 202 code))
- ttl
- %narinfo-transient-error-ttl))
result))))
(define (do-fetch uri)
--
2.30.1
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: bug#47897: [PATCH] substitutes: Don't cache negative lookups or transient errors. |
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Date: |
Sun, 16 May 2021 23:31:05 +0200 |
|
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) |
Hi,
Christopher Baines <mail@cbaines.net> skribis:
> The patches you've sent look good.
Pushed as 938ffcbb0589adc07dc12c79eda3e1e2bb9e7cf8 (I was generous and
lowered ‘%narinfo-negative-ttl’ to 10mn :-)).
Thanks,
Ludo’.
--- End Message ---