mikeal/request — Issue #101: Requests does not fire requests in parallel?
Author: jesseditson
Created: 2011-11-02 18:06:21+00:00
State: open

I have an app that uses request to grab API data from an internal API.

I was doing some tests, and it seemed that our app was scaling poorly under heavy load, and API responses were getting incrementally slower.

I deduced this down to the request call we're using, and it looks like request is probably firing these in a queue, not all at once. Here's a test script that shows this behavior:

```javascript

#!/usr/bin/env node
var request = require("request"),
logger = require("./logger.js"),
argv = require("optimist").argv;
var numRequests = argv.requests || argv.r,
requestsMade = 0,
wait = argv.wait || argv.w || 0,
url = argv.url || argv.u || "http://www.google.com",
requestApi = function(url,callback){
var requestTime = new Date().getTime();
request({
method: "GET",
uri: url
},function(err, response, body){
var totalTime = (new Date().getTime()) - requestTime;
callback(err, response, body, totalTime);
});
},
doRequest = function(){
requestsMade++;
if(requestsMade==numRequests) clearInterval(requestMaker);
var thisRequest = requestsMade;
logger.info("Firing Request #"+thisRequest);
requestApi(url,function(err, response, body, totalTime){
if(err){
logger.error("error contacting API ", err, "trying to request ",reqUrl," after ", totalTime, "ms");
} else {
logger.info("Api responded to request #"+thisRequest+" after ", totalTime, "ms");
}
});
};
logger.info("Starting Test with " + numRequests + " Requests.");
var requestMaker = setInterval(doRequest,wait);
```

(logger.js is just a logging tool to print timestamps & set up log levels).

And, a simple test of google shows the incremental slowdown:

```$ node requestTester.js -r 20
[Wed 2011-11-2 11:2:24.575 GMT7] INF: Starting Test with 20 Requests.
[Wed 2011-11-2 11:2:24.580 GMT7] INF: Firing Request #1
[Wed 2011-11-2 11:2:24.654 GMT7] INF: Firing Request #2
[Wed 2011-11-2 11:2:24.661 GMT7] INF: Firing Request #3
[Wed 2011-11-2 11:2:24.664 GMT7] INF: Firing Request #4
[Wed 2011-11-2 11:2:24.667 GMT7] INF: Firing Request #5
[Wed 2011-11-2 11:2:24.672 GMT7] INF: Firing Request #6
[Wed 2011-11-2 11:2:24.673 GMT7] INF: Firing Request #7
[Wed 2011-11-2 11:2:24.674 GMT7] INF: Firing Request #8
[Wed 2011-11-2 11:2:24.675 GMT7] INF: Firing Request #9
[Wed 2011-11-2 11:2:24.675 GMT7] INF: Firing Request #10
[Wed 2011-11-2 11:2:24.676 GMT7] INF: Firing Request #11
[Wed 2011-11-2 11:2:24.677 GMT7] INF: Firing Request #12
[Wed 2011-11-2 11:2:24.678 GMT7] INF: Firing Request #13
[Wed 2011-11-2 11:2:24.679 GMT7] INF: Firing Request #14
[Wed 2011-11-2 11:2:24.680 GMT7] INF: Firing Request #15
[Wed 2011-11-2 11:2:24.681 GMT7] INF: Firing Request #16
[Wed 2011-11-2 11:2:24.682 GMT7] INF: Firing Request #17
[Wed 2011-11-2 11:2:24.683 GMT7] INF: Firing Request #18
[Wed 2011-11-2 11:2:24.684 GMT7] INF: Firing Request #19
[Wed 2011-11-2 11:2:24.685 GMT7] INF: Firing Request #20
[Wed 2011-11-2 11:2:25.257 GMT7] INF: Api responded to request #2 after 602 ms
[Wed 2011-11-2 11:2:25.621 GMT7] INF: Api responded to request #1 after 1041 ms
[Wed 2011-11-2 11:2:25.774 GMT7] INF: Api responded to request #3 after 1113 ms
[Wed 2011-11-2 11:2:25.779 GMT7] INF: Api responded to request #4 after 1115 ms
[Wed 2011-11-2 11:2:25.895 GMT7] INF: Api responded to request #5 after 1228 ms
[Wed 2011-11-2 11:2:26.378 GMT7] INF: Api responded to request #9 after 1703 ms
[Wed 2011-11-2 11:2:26.714 GMT7] INF: Api responded to request #7 after 2041 ms
[Wed 2011-11-2 11:2:26.870 GMT7] INF: Api responded to request #8 after 2196 ms
[Wed 2011-11-2 11:2:27.126 GMT7] INF: Api responded to request #10 after 2449 ms
[Wed 2011-11-2 11:2:27.267 GMT7] INF: Api responded to request #6 after 2595 ms
[Wed 2011-11-2 11:2:27.730 GMT7] INF: Api responded to request #14 after 3051 ms
[Wed 2011-11-2 11:2:28.68 GMT7] INF: Api responded to request #13 after 3389 ms
[Wed 2011-11-2 11:2:28.72 GMT7] INF: Api responded to request #11 after 3395 ms
[Wed 2011-11-2 11:2:28.75 GMT7] INF: Api responded to request #12 after 3398 ms
[Wed 2011-11-2 11:2:28.332 GMT7] INF: Api responded to request #16 after 3650 ms
[Wed 2011-11-2 11:2:28.471 GMT7] INF: Api responded to request #15 after 3791 ms
[Wed 2011-11-2 11:2:29.45 GMT7] INF: Api responded to request #18 after 4362 ms
[Wed 2011-11-2 11:2:29.161 GMT7] INF: Api responded to request #17 after 4479 ms
[Wed 2011-11-2 11:2:29.173 GMT7] INF: Api responded to request #19 after 4488 ms
[Wed 2011-11-2 11:2:29.424 GMT7] INF: Api responded to request #20 after 4738 ms
```

Why does this happen? Is there a config option I missed that will make the requests all fire at once?

I'd hate to have to ditch request as I love it so much, but this is a showstopper for this project.