Merge 6e6d331bd9 into de1a4c463c

rootfs/etc/nginx/lua/balancer/sticky_persistent.lua

@@ -4,18 +4,35 @@
 -- be rebalanced.
 --
 local balancer_sticky = require("balancer.sticky")
+local balancer_round_robin = require("balancer.round_robin")
+local balancer_chash = require("balancer.chash")
+local balancer_chashsubset = require("balancer.chashsubset")
+local balancer_ewma = require("balancer.ewma")
 local util_get_nodes = require("util").get_nodes
 local util_nodemap = require("util.nodemap")
 local setmetatable = setmetatable
 
+local function get_secondary_balancer(backend)
+  local name = backend["load-balance"]
+
+  if not name then return nil
+  elseif name == "chash" then return balancer_chash:new(backend)
+  elseif name == "chashsubset" then return balancer_chashsubset:new(backend)
+  elseif name == "round_robin" then return balancer_round_robin:new(backend)
+  elseif name == "ewma" then return balancer_ewma:new(backend)
+  end
+end
+
 local _M = balancer_sticky:new()
 
 function _M.new(self, backend)
   local nodes = util_get_nodes(backend.endpoints)
   local hash_salt = backend["name"]
+  local secondary_balancer = get_secondary_balancer(backend)
 
   local o = {
     name = "sticky_persistent",
+    secondary_balancer = secondary_balancer,
     instance = util_nodemap:new(nodes, hash_salt)
   }
 
@@ -28,7 +45,29 @@ function _M.new(self, backend)
 end
 
 function _M.pick_new_upstream(self, failed_upstreams)
+  if self.secondary_balancer then
+    local endpoint = self.secondary_balancer:balance()
+    local key = self.instance:key_from_endpoint(endpoint)
+    if endpoint and key then
+      return endpoint, key
+    end
+  end
+
   return self.instance:random_except(failed_upstreams)
 end
 
+function _M.sync(self, backend)
+  -- sync inherited balancer
+  balancer_sticky.sync(self, backend)
+  
+  -- note this may be inefficient
+  -- perhaps better to only update if name changes?
+  self.secondary_balancer = get_secondary_balancer(backend)
+
+  -- sync secondary_balancer as well
+  if self.secondary_balancer then
+    self.secondary_balancer:sync(backend)
+  end
+end
+
 return _M

rootfs/etc/nginx/lua/util/nodemap.lua

@@ -122,4 +122,13 @@ function _M.random_except(self, ignore_nodes)
   return get_random_node(valid_nodes)
 end
 
+--- find the key of a given endpoint
+-- @tparam string endpoint The endpoint.
+-- @treturn string The key for endpoint or nil.
+function _M.key_from_endpoint(self, endpoint)
+  for k, v in pairs(self.map) do
+    if v==endpoint then return k end
+  end
+end
+
 return _M