背景

node作为中间层调用后端java服务端接口。

问题

curl请求后端接口报错ResponseError: Parse Error。没有超时，因为是立即返回的，直接报错了。不是每个接口都会报错，只有一两个接口会报错。部署到linux服务器上报错，本地不报错。而且在linux服务器上直接用curl命令发起请求看到服务端是正常返回的。
报错信息如下：

ResponseError: Parse Error, POST http://10.16.70.183:9104/xres-rms/service/rs/v1/deviceService/save -1 (connected: true, keepalive socket: false, agent status: {"createSocketCount":20,"createSocketErrorCount":0,"closeSocketCount":19,"errorSocketCount":0,"timeoutSocketCount":18,"requestCount":29,"freeSockets":{},"sockets":{"10.16.70.183:9104:":1},"requests":{}}, socketHandledRequests: 1, socketHandledResponses: 0)
headers: {}

at Socket.socketOnData (_http_client.js:452:22)
at Socket.emit (events.js:200:13)
at addChunk (_stream_readable.js:294:12)
at readableAddChunk (_stream_readable.js:275:11)
at Socket.Readable.push (_stream_readable.js:210:10)
at TCP.onStreamRead (internal/stream_base_commons.js:166:17)

排查步骤

1. 是否是服务器的设置问题。
2. 列表项目

在服务器上用命令curl发起请求，看是否正常。curl发起请求的命令如下

curl -X POST \
  http://10.19.132.127:9104/xres-rms/service/rs/v1/deviceService/save \
  -H 'Content-Type: application/json' \
  -H 'Postman-Token: 4b9c514b-2444-4f3e-850c-2629987fcac4' \
  -H 'TOKEN: SElLIDBPUENpUGNPZm5JNkVQbDQ6N3pHaTNmcWJxNnFIRWdEeTh5dTZ2ZmpWb1NMZi9uaUNFTWY2cE11ZHFTWT06MTU2NjYxNTQ4NDA5Ng==' \
  -H 'cache-control: no-cache' \
  -d '{ "resourceType": "ENCODE_DEVICE",
  "externalIndexCode": "10000000001320939591",
  "userPwd": "EQAQAODkw0AuqpGM21fuUtkYDOzQfnlKYi7FWLSSSOYtjwexwFAmeienXbEF4BkFWyaOjA==",
  "treatyType": "hiksdk_net",
  "netZoneId": 0,
  "manufacturer": "hikvision",
  "tag": "@@",
  "tagPath": "$$",
  "addType": 1,
  "networkAddr": "1.1.6.1",
  "networkPort": 8001,
  "userName":"admin",
  "belongIndexCode": "",
  "deviceClass": "100001",
  "analogChanCount": 0,
  "digitalChanCount": 0,
  "alarmInCount": 0,
  "alarmOutCount": 0,
  "regionIndexCode": "ed87743033f3459f814edaf1cc0d4420",
  "deviceCategory": "vss",
  "pwdStrength": 3 }'

可以看出不是服务器的设置问题，应该是代码问题。既然不是代码问题，先抓包看看数据分析一下。

1. 用tcpdump抓包看请求

打开linux服务器，输入以下命令:

tcpdump -i eth0 '((tcp) and (port 9104) and (dst host 10.19.132.127))' -w out.cap

抓取发送到10.19.132.127，端口是9104的所有tcp请求，并输出并保存到out.cap文件 eth0表示网卡，查询网卡用命令

ip a

1. 用wireshark打开请求的接口，查看详情

可以看出没有收到response
看下正常的response是这样的

是会有个response in frame的。
可以确定确实没有收到response。
但是em…为什么node版本是12.4？？最新的稳定版本明明是10.16.3啊。。可以看node官网查看最新版本是12.9.1，为了验证我的猜想，我安装了最新的12.9.1的版本，于是本地接口也报错了

ResponseError: Parse Error: Invalid header value char, POST http://10.19.132.127:8020/xres-res/service/rs/resourceOrgRestService/v1/batchDeleteResourceOrg -1 (connected: true, keepalive socket: true, agent status: {"createSocketCount":6,"createSocketErrorCount":0,"closeSocketCount":5,"errorSocketCount":0,"timeoutSocketCount":5,"requestCount":12,"freeSockets":{},"sockets":{"10.19.132.127:8020:":1},"requests":{}}, socketHandledRequests: 4, socketHandledResponses: 3)
headers: {}
at Socket.socketOnData (_http_client.js:456:22)
at Socket.emit (events.js:209:13)
at addChunk (_stream_readable.js:305:12)
at readableAddChunk (_stream_readable.js:286:11)
at Socket.Readable.push (_stream_readable.js:220:10)
at TCP.onStreamRead (internal/stream_base_commons.js:166:17)

这里非常明显的看到了错误原因

ResponseError: Parse Error: Invalid header value char

响应头解析失败。打断点查看响应头，把本地的node版本改回稳定版本10.16.3，看到的数据如下

{ notation: '@\tѧ¹òsTvÖDÖsTsû\u000eÍ° dѧ¹',
  span_id: '78f9edd00a134b5d8c4b4bc3c35dd1bf',
  date: 'Mon, 26 Aug 2019 06:07:51 GMT',
  connection: 'keep-alive',
  'content-type': 'application/json',
  'content-length': '134',
  'x-application-context': 'xres-res:dev:8020',
  trace_id: '682033d4866c4438b26978cce00c4520',
  code: '0x08f70038' }

可以看到notation这里乱码了，导致了解析失败。

结论

node12用了新的http-parser，所以对响应头的要求更严格了，导致了解析失败~
用最新版的node需谨慎，现在都还是踩坑的阶段~~