| -- |
| -- Licensed to the Apache Software Foundation (ASF) under one or more |
| -- contributor license agreements. See the NOTICE file distributed with |
| -- this work for additional information regarding copyright ownership. |
| -- The ASF licenses this file to You under the Apache License, Version 2.0 |
| -- (the "License"); you may not use this file except in compliance with |
| -- the License. You may obtain a copy of the License at |
| -- |
| -- http://www.apache.org/licenses/LICENSE-2.0 |
| -- |
| -- Unless required by applicable law or agreed to in writing, software |
| -- distributed under the License is distributed on an "AS IS" BASIS, |
| -- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| -- See the License for the specific language governing permissions and |
| -- limitations under the License. |
| -- |
| |
| local roundrobin = require("resty.roundrobin") |
| local core = require("apisix.core") |
| local nkeys = core.table.nkeys |
| local pairs = pairs |
| |
| |
| local _M = {} |
| |
| |
| function _M.new(up_nodes, upstream) |
| local safe_limit = 0 |
| for _, weight in pairs(up_nodes) do |
| -- the weight can be zero |
| safe_limit = safe_limit + weight + 1 |
| end |
| |
| local picker = roundrobin:new(up_nodes) |
| local nodes_count = nkeys(up_nodes) |
| return { |
| upstream = upstream, |
| get = function (ctx) |
| if ctx.balancer_tried_servers and ctx.balancer_tried_servers_count == nodes_count then |
| return nil, "all upstream servers tried" |
| end |
| |
| local server, err |
| for i = 1, safe_limit do |
| server, err = picker:find() |
| if not server then |
| return nil, err |
| end |
| if ctx.balancer_tried_servers then |
| if not ctx.balancer_tried_servers[server] then |
| break |
| end |
| else |
| break |
| end |
| end |
| |
| return server |
| end, |
| after_balance = function (ctx, before_retry) |
| if not before_retry then |
| if ctx.balancer_tried_servers then |
| core.tablepool.release("balancer_tried_servers", ctx.balancer_tried_servers) |
| ctx.balancer_tried_servers = nil |
| end |
| |
| return nil |
| end |
| |
| if not ctx.balancer_tried_servers then |
| ctx.balancer_tried_servers = core.tablepool.fetch("balancer_tried_servers", 0, 2) |
| end |
| |
| ctx.balancer_tried_servers[ctx.balancer_server] = true |
| ctx.balancer_tried_servers_count = (ctx.balancer_tried_servers_count or 0) + 1 |
| end, |
| before_retry_next_priority = function (ctx) |
| if ctx.balancer_tried_servers then |
| core.tablepool.release("balancer_tried_servers", ctx.balancer_tried_servers) |
| ctx.balancer_tried_servers = nil |
| end |
| |
| ctx.balancer_tried_servers_count = 0 |
| end, |
| } |
| end |
| |
| |
| return _M |