【运维发布】连接数监控：数据库连接的水位线管理

local WARN_PCT, CRIT_PCT = 70, 90
local MAX_CONN = 200
setontimerex(217, 30)
function ontimer217()
    local cur = getConnectionCount()
    local pct = math.floor(cur * 100 / MAX_CONN)
    if pct >= CRIT_PCT then
        sendmail("#DBA组", 948, "连接数红线告警",
            "连接数 " .. cur .. "/" .. MAX_CONN .. " 达到 " .. pct .. "%", "")
    elseif pct >= WARN_PCT then
        sendmail("#值班老张", 949, "连接数黄线预警",
            "连接数 " .. cur .. "/" .. MAX_CONN .. " 达到 " .. pct .. "%", "")
    end
end

local prevConn = 0
local function checkLeak(cur, reqDelta)
    local connDelta = cur - prevConn
    if connDelta > 0 and reqDelta <= 0 then
        sendmail("#DBA组", 950, "连接泄漏疑似",
            "连接增量 " .. connDelta .. " 而请求无增量，可能存在泄漏", "")
    end
    prevConn = cur
end