系统信息
操作系统名称：Microsoft Windows 10 Enterprise
操作系统版本：10.0.17134 N/A 内部版本 17134
MongoDB 版本
MongoDB 4.2.1 x64 Windows。
概述
与独立 mongod 实例建立连接时
PS C:\MongoDB> .\mongod.exe --dbpath C:\data
在客户端和服务器之间建立连接时会出现明显的延迟，10-25 秒。
注意：C:\MongoDB>.\mongo.exe 127.0.0.1:27017
我们已经排除了该问题与防火墙和代理有关的理论。
分析
对齐客户端和服务器的详细日志会显示处理管理命令时的延迟。
（> = 服务器，~ = 客户端）
~ MongoDB shell version v4.2.1
~ connecting to: mongodb://127.0.0.1:27017/admin?compressors=disabled&gssapiServiceName=mongodb
~ 2019-11-14T02:23:29.803-0800 D1 NETWORK [js] creating new connection to:127.0.0.1:27017
> 2019-11-14T02:23:29.806-0800 I NETWORK [listener] connection accepted from 127.0.0.1:60413 #1 (1 connection now open)
> 2019-11-14T02:23:29.806-0800 D3 EXECUTOR [listener] Starting new executor thread in passthrough mode
~ 2019-11-14T02:23:29.806-0800 D1 NETWORK [js] connected to server 127.0.0.1:27017
> 2019-11-14T02:23:46.635-0800 D2 COMMAND [conn1] run command admin.$cmd { isMaster: 1, hostInfo: "REDACTED:27017", client: { application: { name: "MongoDB Shell" }, driver: { name: "MongoDB Internal Client", version: "4.2.1" }, os: { type: "Windows", name: "Microsoft Windows 10", architecture: "x86_64", version: "10.0 (build 17134)" } }, $db: "admin" }
> 2019-11-14T02:23:46.635-0800 I NETWORK [conn1] received client metadata from 127.0.0.1:60413 conn1: { application: { name: "MongoDB Shell" }, driver: { name: "MongoDB Internal Client", version: "4.2.1" }, os: { type: "Windows", name: "Microsoft Windows 10", architecture: "x86_64", version: "10.0 (build 17134)" } }
> 2019-11-14T02:23:46.635-0800 D3 NETWORK [conn1] Starting server-side compression negotiation
> 2019-11-14T02:23:46.635-0800 D3 NETWORK [conn1] Compression negotiation not requested by client
> 2019-11-14T02:23:46.635-0800 I COMMAND [conn1] command admin.$cmd appName: "MongoDB Shell" command: isMaster { isMaster: 1, hostInfo: "REDACTED:27017", client: { application: { name: "MongoDB Shell" }, driver: { name: "MongoDB Internal Client", version: "4.2.1" }, os: { type: "Windows", name: "Microsoft Windows 10", architecture: "x86_64", version: "10.0 (build 17134)" } }, $db: "admin" } numYields:0 reslen:257 locks:{} protocol:op_query 0ms
~ 2019-11-14T02:23:46.636-0800 D1 NETWORK [js] connected connection!
~ Implicit session: session { "id" : UUID("a1c87b79-d721-4d57-b3f9-c17aa9db41cd") }
~ MongoDB server version: 4.2.1
覆盖 Wireshark 捕获的网络通信
Time Source Destination Protocol Port Length Info
02:23:29.805873 127.0.0.1 127.0.0.1 TCP 60413,27017 56 60413 → 27017 [SYN] Seq=0 Win=64240 Len=0 MSS=65495 WS=256 SACK_PERM=1
02:23:29.805954 127.0.0.1 127.0.0.1 TCP 27017,60413 56 27017 → 60413 [SYN, ACK] Seq=0 Ack=1 Win=65535 Len=0 MSS=65495 WS=256 SACK_PERM=1
02:23:29.806041 127.0.0.1 127.0.0.1 TCP 60413,27017 44 60413 → 27017 [ACK] Seq=1 Ack=1 Win=525568 Len=0
02:23:29.816470 127.0.0.1 127.0.0.1 SSL 60413,27017 368 Continuation Data
02:23:29.816569 127.0.0.1 127.0.0.1 TCP 27017,60413 44 27017 → 60413 [ACK] Seq=1 Ack=325 Win=525568 Len=0
02:23:46.636463 127.0.0.1 127.0.0.1 SSL 27017,60413 301 Continuation Data
02:23:46.636562 127.0.0.1 127.0.0.1 TCP 60413,27017 44 60413 → 27017 [ACK] Seq=325 Ack=258 Win=525312 Len=0
02:23:46.637297 127.0.0.1 127.0.0.1 SSL 60413,27017 105 Continuation Data
02:23:46.637364 127.0.0.1 127.0.0.1 TCP 27017,60413 44 27017 → 60413 [ACK] Seq=258 Ack=386 Win=525312 Len=0
02:23:46.637991 127.0.0.1 127.0.0.1 SSL 27017,60413 111 Continuation Data
02:23:46.638079 127.0.0.1 127.0.0.1 TCP 60413,27017 44 60413 → 27017 [ACK] Seq=386 Ack=325 Win=525056 Len=0
02:23:46.646216 127.0.0.1 127.0.0.1 SSL 60413,27017 108 Continuation Data
02:23:46.646297 127.0.0.1 127.0.0.1 TCP 27017,60413 44 27017 → 60413 [ACK] Seq=325 Ack=450 Win=525312 Len=0
02:23:46.646984 127.0.0.1 127.0.0.1 SSL 27017,60413 1186 Continuation Data
特别参考以下 2 个包
02:23:29.816569 127.0.0.1 127.0.0.1 TCP 27017,60413 44 27017 → 60413 [ACK] Seq=1 Ack=325 Win=525568 Len=0
02:23:46.636463 127.0.0.1 127.0.0.1 SSL 27017,60413 301 Continuation Data
看起来 mongod 在初始响应和发送延续数据之间有大约 15 秒的延迟。
问题
您是否遇到过这个问题？可以做些什么来尽量减少延迟？