From 8915b15f8c367ef3ebb1299a57f482146825545b Mon Sep 17 00:00:00 2001 From: themez Date: Thu, 26 Sep 2019 11:56:59 +0800 Subject: [PATCH] http: add reusedSocket property on client request Set ClientRequest.reusedSocket property when reusing socket for request, so user can handle retry base on wether the request is reusing a socket. Refs: https://github.com/request/request/issues/3131 PR-URL: https://github.com/nodejs/node/pull/29715 Reviewed-By: Matteo Collina Reviewed-By: Benjamin Gruenbaum Reviewed-By: Weijia Wang --- doc/api/http.md | 56 ++++++++++++++++++++++ lib/_http_agent.js | 1 + lib/_http_client.js | 1 + test/parallel/test-http-agent-keepalive.js | 9 ++-- 4 files changed, 64 insertions(+), 3 deletions(-) diff --git a/doc/api/http.md b/doc/api/http.md index 351add59b55373..2f1b37064b864e 100644 --- a/doc/api/http.md +++ b/doc/api/http.md @@ -676,6 +676,62 @@ Removes a header that's already defined into headers object. request.removeHeader('Content-Type'); ``` +### request.reusedSocket + + + +* {boolean} Whether the request is send through a reused socket. + +When sending request through a keep-alive enabled agent, the underlying socket +might be reused. But if server closes connection at unfortunate time, client +may run into a 'ECONNRESET' error. + +```js +const http = require('http'); + +// Server has a 5 seconds keep-alive timeout by default +http + .createServer((req, res) => { + res.write('hello\n'); + res.end(); + }) + .listen(3000); + +setInterval(() => { + // Adapting a keep-alive agent + http.get('http://localhost:3000', { agent }, (res) => { + res.on('data', (data) => { + // Do nothing + }); + }); +}, 5000); // Sending request on 5s interval so it's easy to hit idle timeout +``` + +By marking a request whether it reused socket or not, we can do +automatic error retry base on it. + +```js +const http = require('http'); +const agent = new http.Agent({ keepAlive: true }); + +function retriableRequest() { + const req = http + .get('http://localhost:3000', { agent }, (res) => { + // ... + }) + .on('error', (err) => { + // Check if retry is needed + if (req.reusedSocket && err.code === 'ECONNRESET') { + retriableRequest(); + } + }); +} + +retriableRequest(); +``` + ### request.setHeader(name, value)