[pve-devel] [PATCH manager 1/4] API2Tools: rrd: remove O(n^2) lookup for keys

[Dominik Csapak <d.csapak@proxmox.com>]

the idea was that we get any of the 'new' versions on lookup, but that
lead to iterating through possibly all keys. Since that was called for
each resource in e.g. /cluster/resources api call, the runtime was
O(n^2) for the number of resources.

To avoid that, simply look up the currently only valid key here which
makes this lookup much cheaper.

In my test setup with ~10000 guests, it reduces the time for a call
to /cluster/resources from ~22s to ~400ms

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
NOTE: this is only a workaround and Aaron is working to making this
whole part unnecessary, but for now i think this is a good stop-gap

 PVE/API2Tools.pm | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/PVE/API2Tools.pm b/PVE/API2Tools.pm
index abe73fa2..863f5f55 100644
--- a/PVE/API2Tools.pm
+++ b/PVE/API2Tools.pm
@@ -52,10 +52,9 @@ sub get_rrd_key {
         return "pve2.3-${type}/${id}";
     }
 
-    # if no old key has been found, we expect on in the newer format: pve-{type}-{version}/{id}
-    # We accept all new versions, as the expectation is that they are only allowed to add new colums as non-breaking change
-    for my $k (keys %$rrd) {
-        return $k if $k =~ m/^pve-\Q${type}\E-\d\d?.\d\/\Q${id}\E$/;
+    my $key = "pve-${type}-9.0/${id}";
+    if (defined($rrd->{$key})) {
+        return $key;
     }
 }
 
-- 
2.47.2



_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel