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| author | Alban Lecocq <alban@lempire.co> | 2022-12-05 19:28:12 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-12-05 11:28:12 -0700 |
| commit | d4a7d89f564234e44012a763cc28c5a3991bd98e (patch) | |
| tree | 30a17b7cfaaa5f6bd6a71d599af8621fe1948cb7 /modules/caddyhttp/reverseproxy/selectionpolicies.go | |
| parent | ae77a56ac8761bfe064904bd7098a952d3221034 (diff) | |
reverseproxy: Improve hostByHashing distribution (#5229)
* If upstreams are all using same host but with different ports
ie:
foobar:4001
foobar:4002
foobar:4003
...
Because fnv-1a has not a good enough avalanche effect
Then the hostByHashing result is not well balanced over
all upstreams
As last byte FNV input tend to affect few bits, the idea is to change
the concatenation order between the key and the upstream strings
So the upstream last byte have more impact on hash diffusion
Diffstat (limited to 'modules/caddyhttp/reverseproxy/selectionpolicies.go')
| -rw-r--r-- | modules/caddyhttp/reverseproxy/selectionpolicies.go | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/modules/caddyhttp/reverseproxy/selectionpolicies.go b/modules/caddyhttp/reverseproxy/selectionpolicies.go index 2de830c..0b7f50c 100644 --- a/modules/caddyhttp/reverseproxy/selectionpolicies.go +++ b/modules/caddyhttp/reverseproxy/selectionpolicies.go @@ -528,7 +528,7 @@ func hostByHashing(pool []*Upstream, s string) *Upstream { if !up.Available() { continue } - h := hash(s + up.String()) // important to hash key and server together + h := hash(up.String() + s) // important to hash key and server together if h > highestHash { highestHash = h upstream = up |