DataStore Request Limit Exceeded (HTTP 429): Quota Budget & Retry Backoff

-- ✅ PRODUCTION FIX: Memory-First Session Cache with Graceful Flush
local DataStoreService = game:GetService("DataStoreService")
local Players = game:GetService("Players")

local coinDataStore = DataStoreService:GetDataStore("PlayerCoins_v1")
local sessionCache: { [number]: number } = {}

-- 1. Mutate in-memory only during gameplay (0 API cost)
local function onCoinCollected(player: Player, amount: number)
    local userId = player.UserId
    sessionCache[userId] = (sessionCache[userId] or 0) + amount
end

-- 2. Exponential backoff wrapper for API operations
local function safeSave(userId: number, value: number, maxRetries: number?): boolean
    local retries = maxRetries or 3
    for attempt = 1, retries do
        local success, err = pcall(function()
            coinDataStore:UpdateAsync(tostring(userId), function(oldValue)
                return value
            end)
        end)
        
        if success then
            return true
        else
            warn(string.format("[DataStore] Save failed for %d (Attempt %d): %s", userId, attempt, tostring(err)))
            task.wait(2 ^ attempt) -- Exponential backoff: 2s, 4s, 8s
        end
    end
    return false
end

-- 3. Flush to DataStore on player exit
Players.PlayerRemoving:Connect(function(player)
    local userId = player.UserId
    if sessionCache[userId] then
        safeSave(userId, sessionCache[userId])
        sessionCache[userId] = nil
    end
end)