【运维发布】资源水位应用：扩容决策与降配回收的完整链路

-- 降配评估：观察期识别
local player = class(actor)
local LOW_LINE = 20
local function evalDownscale(player, res, weekAvgs)
    if #weekAvgs < 4 then
        sendmsg(player, 1, 0, "数据不足四周，暂不评估降配。")
        return false
    end
    local allLow = true
    for _, avg in ipairs(weekAvgs) do
        if avg > LOW_LINE then allLow = false end
    end
    if allLow then
        setsysvarex("DownscaleObserve_" .. res, os.date("%Y%W"), true)
        sendmsg(player, 1, 0, res .. " 连续四周低于 " .. LOW_LINE .. "%，进入一周观察期。")
    end
    return allLow
end

-- 缩容执行：分批与回滚
local player = class(actor)
local function downscaleBatch(player, res, batch)
    local released = math.floor(batch.total * 0.3)
    setsysvarex("Scale_" .. res, batch.total - released, true)
    sendmsg(player, 1, 0, res .. " 首批缩容 " .. released .. " 台，观察 72 小时。")
    local rollbackPlan = "回滚预案：异常时调用扩容接口一次性恢复 " .. batch.total .. " 台"
    sendmsg(player, 1, 0, rollbackPlan)
    batch.done = batch.done + released
end