Question

我们已经为我们的网络服务实现了基于Redis的速率限制，该速率取自here。我在这里复制相关代码。

local limits = cjson.decode(ARGV[1])
local now = tonumber(ARGV[2])
local weight = tonumber(ARGV[3] or '1')
local longest_duration = limits[1][1] or 0
local saved_keys = {}
-- handle cleanup and limit checks
for i, limit in ipairs(limits) do

local duration = limit[1]
longest_duration = math.max(longest_duration, duration)
local precision = limit[3] or duration
precision = math.min(precision, duration)
local blocks = math.ceil(duration / precision)
local saved = {}
table.insert(saved_keys, saved)
saved.block_id = math.floor(now / precision)
saved.trim_before = saved.block_id - blocks + 1
saved.count_key = duration .. ':' .. precision .. ':'
saved.ts_key = saved.count_key .. 'o'
for j, key in ipairs(KEYS) do

    local old_ts = redis.call('HGET', key, saved.ts_key)
    old_ts = old_ts and tonumber(old_ts) or saved.trim_before
    if old_ts > now then
        -- don't write in the past
        return 1
    end

    -- discover what needs to be cleaned up
    local decr = 0
    local dele = {}
    local trim = math.min(saved.trim_before, old_ts + blocks)
    for old_block = old_ts, trim - 1 do
        local bkey = saved.count_key .. old_block
        local bcount = redis.call('HGET', key, bkey)
        if bcount then
            decr = decr + tonumber(bcount)
            table.insert(dele, bkey)
        end
    end

    -- handle cleanup
    local cur
    if #dele > 0 then
        redis.call('HDEL', key, unpack(dele))
        cur = redis.call('HINCRBY', key, saved.count_key, -decr)
    else
        cur = redis.call('HGET', key, saved.count_key)
    end

    -- check our limits
    if tonumber(cur or '0') + weight > limit[2] then
        return 1
    end
  end
end

我正在尝试弄清评论的含义-过去不要写 我看不出old_ts大于now的情况怎么可能我已经在lua代码中放置了日志，但是没有成功。

如果old_ts为1并且saved.trim_before为1，则now最多可以等于precision，而后者又可以等于blocks。更大的。如果有人对此有见识，这将很有帮助。

Answer 1

如果您查看文章中提供的要旨

https://gist.github.com/josiahcarlson/80584b49da41549a7d5c

有询问的评论

In over_limit_sliding_window_lua_, should

if old_ts > now then

at here be

if old_ts > saved.block_id then

我同意，old_ts应该具有bucket，并且当存储桶跳转到下一个插槽时，也就是说old_ts会比{ {1}}

用lua限制速率

1 个答案: