| -- |
| -- 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 core = require("apisix.core") |
| local ipairs = ipairs |
| |
| |
| local _M = {} |
| |
| |
| local function max_priority(a, b) |
| return a > b |
| end |
| |
| |
| function _M.new(up_nodes, upstream, picker_mod) |
| local priority_index = up_nodes._priority_index |
| core.table.sort(priority_index, max_priority) |
| |
| local pickers = core.table.new(#priority_index, 0) |
| for i, priority in ipairs(priority_index) do |
| local picker, err = picker_mod.new(up_nodes[priority], upstream) |
| if not picker then |
| return nil, "failed to create picker with priority " .. priority .. ": " .. err |
| end |
| if not picker.before_retry_next_priority then |
| return nil, "picker should define 'before_retry_next_priority' to reset ctx" |
| end |
| |
| pickers[i] = picker |
| end |
| |
| return { |
| upstream = upstream, |
| get = function (ctx) |
| for i = ctx.priority_balancer_picker_idx or 1, #pickers do |
| local picker = pickers[i] |
| local server, err = picker.get(ctx) |
| if server then |
| ctx.priority_balancer_picker_idx = i |
| return server |
| end |
| |
| core.log.notice("failed to get server from current priority ", |
| priority_index[i], |
| ", try next one, err: ", err) |
| |
| picker.before_retry_next_priority(ctx) |
| end |
| |
| return nil, "all servers tried" |
| end, |
| after_balance = function (ctx, before_retry) |
| local priority_balancer_picker = pickers[ctx.priority_balancer_picker_idx] |
| if not priority_balancer_picker or |
| not priority_balancer_picker.after_balance |
| then |
| return |
| end |
| |
| priority_balancer_picker.after_balance(ctx, before_retry) |
| end |
| } |
| end |
| |
| |
| return _M |