02/03: nginx: mirror: Cache nars for 30 days only.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository maintenance.

commit ebf446a8542556d32b0c27f7821f29fd27b8b3f5
Author: Ludovic Courtès <address@hidden>
Date:   Mon Aug 28 15:14:56 2017 +0200

    nginx: mirror: Cache nars for 30 days only.
    
    * hydra/nginx/mirror-locations.conf (/nar): Cache 200 responses for 30
    days.  Remove 'proxy_cache_valid' directory for 504.
---
 hydra/nginx/mirror-locations.conf | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/hydra/nginx/mirror-locations.conf 
b/hydra/nginx/mirror-locations.conf
index 34ab3f9..882e9bc 100644
--- a/hydra/nginx/mirror-locations.conf
+++ b/hydra/nginx/mirror-locations.conf
@@ -35,12 +35,13 @@ location ~ /nar/ {
     proxy_read_timeout 60s;
     proxy_send_timeout 60s;
 
-    # Enable caching for nar files, to avoid reconstructing and recompressing
-    # archives.
+    # XXX: If builds were all bit-reproducible, we could cache nars
+    # much longer.  However they are not, so we can end up with hash
+    # mismatches between the narinfos and the cached nars we have.
+    # Thus, cache for a limited amount of time.
     proxy_cache nar;
-    proxy_cache_valid 200 91d;   # cache hits for 3 months.
-    proxy_cache_valid 504 3m;    # timeout, when hydra.gnu.org is overloaded
-    proxy_cache_valid any 20m;   # cache misses/others for 20m
+    proxy_cache_valid 200 30d;   # cache hits for 1 month
+    proxy_cache_valid any 5m;    # others for 5m
 
     proxy_ignore_client_abort on;