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wg
wrk
C2012–2024
wg / wrk

wrk

Modern HTTP benchmarking tool

34Distinct people
42Mentions
3Explicit recommenders
40.4KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Modern HTTP benchmarking tool

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

We use locust at work but I HIGHLY recommend wrk for a very robust yet simple load testing tool. https://github.com/wg/wrk And of course, this talk by Gil Tene is fantastic if…

leetrout used a recommendation phrase. 3 indexed comments match. This is a phrase match, not a verdict.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 2:59:58 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year42 dated mentions

Observed mentions: 2012-04-03 22:57:01 UTC to 2024-09-15 08:00:52 UTC.

0369122012-01-01 00:00:00 UTC to 2013-01-01 00:00:00 UTC (exclusive): 2 mentions; 1 submissions, 1 comments20122013-01-01 00:00:00 UTC to 2014-01-01 00:00:00 UTC (exclusive): 12 mentions; 2 submissions, 10 comments2014-01-01 00:00:00 UTC to 2015-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2015-01-01 00:00:00 UTC to 2016-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2016-01-01 00:00:00 UTC to 2017-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments20182019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 3 mentions; 1 submissions, 2 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 2 mentions; 1 submissions, 1 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments2024

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20122012-01-01 00:00:00 UTC2013-01-01 00:00:00 UTC211
20132013-01-01 00:00:00 UTC2014-01-01 00:00:00 UTC12210
20142014-01-01 00:00:00 UTC2015-01-01 00:00:00 UTC101
20152015-01-01 00:00:00 UTC2016-01-01 00:00:00 UTC404
20162016-01-01 00:00:00 UTC2017-01-01 00:00:00 UTC404
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC101
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC202
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC202
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC312
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC404
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC211
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC202
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC303

From the project README

An excerpt from the repository, fetched Nov 13, 2026.

Read the project’s introduction
wrk - a HTTP benchmarking tool wrk is a modern HTTP benchmarking tool capable of generating significant load when run on a single multi-core CPU. It combines a multithreaded design with scalable event notification systems such as epoll and kqueue. An optional LuaJIT script can perform HTTP request generation, response processing, and custom reporting. Details are available in SCRIPTING and several examples are located in scripts/. Basic Usage wrk -t12 -c400 -d30s http://127.0.0.1:8080/index.html This runs a benchmark for 30 seconds, using 12 threads, and keeping 400 HTTP connections open. Output: Running 30s test @ http://127.0.0.1:8080/index.html 12 threads and 400 connections Thread Stats Avg Stdev Max +/- Stdev Latency 635.91us 0.89ms 12.92ms 93.69% Req/Sec 56.20k 8.07k 62.00k 86.54% 22464657 requests in 30.00s, 17.76GB read Requests/sec: 748868.53 Transfer/sec: 606.33MB Command Line Options -c, --connections: total number of HTTP connections to keep open with each thread handling N = connections/threads -d, --duration: duration of the test, e.g. 2s, 2m, 2h -t, --threads: total number of threads to use -s, --script: LuaJIT script, see SCRIPTING -H, --header: HTTP header to add to request, e.g. "User-Agent: wrk" --latency: print detailed latency statistics --timeout: record a timeout if a response is not received within this amount of time. Benchmarking Tips The machine running wrk must have a sufficient number of ephemeral ports available and closed sockets should be recycled quickly. To handle the initial connection burst the server's listen(2) backlog should be greater than the number of concurrent connections being tested. A user script that only changes the HTTP method, path, adds headers or a body, will have no performance impact. Per-request actions, particularly building a new HTTP request, and use of response() will necessarily reduce the amount of load that can be generated. Acknowledgements wrk contains code from a number of open source projects including the 'ae' event loop from redis, the nginx/joyent/node.js 'http-parser', and Mike Pall's LuaJIT. Please consult the NOTICE file for licensing details. Cryptography Notice This distribution includes cryptographic software. The country in which you currently reside may have restrictions on the import, possession, use, and/or re-export to another country, of encryption software. BEFORE using any encryption software, please check your country's laws, regulations and policies concerning the import, possession, or use, and re-export of encryption software, to see if this is permitted. See http://www.wassenaar.org/ for more information. The U.S. Government Department of Commerce, Bureau of Industry and Security (BIS), has classified this software as Export Commodity Control Number (ECCN) 5D002.C.1, which includes information security software using or performing cryptographic functions with symmetric algorithms. The form and manner of this distribution makes it eligible for export under the License Exception ENC Technology Software Unrestricted (TSU) exception (see the BIS Export Administration Regulations, Section 740.13) for both object code and source code.
Read the full README on GitHub

What Hacker News says

2 sources
Here's an insightful comment from the blog page, about cpu and memory usage: I downloaded patricks fork and got 4300r/s with maxprocs 1 with the go version, out the box. Recompiling and running with gomaxprocs=100, i got 4400r/s. mvn deploy and running auth-1.0.jar on JDK 1.7 on my box similarly peaked out at 3100r/s. It's worth noting though, that I was using patricks httperf bench.sh modification, and it appears that httperf was cpu bound in both cases, with the kernel and postres taking about half a core between them. Using wrk, by contrast, spun main (the go program) up to 2.5 cores, and 6000r/s. Java under wrk lit all cores for a time, then hit `Exception in thread "async-log-appender-0" java.lang.OutOfMemoryError: Java heap space` `Caused by: ! org.postgresql.util.PSQLException: FATAL: sorry, too many clients already` A bit more inv
Read the rest
estigation and tuning later, using 10 clients `wrk -c 10 -r 100000 -t 4 -H 'Authorization: basic apikey_value' http://localhost:8080/authenticate` Java was spinning out 10kr/s. Go was limited to 6kr/s. It's worth noting some more details however: Go only ever spun up two postgres forks, whereas java spun up 10. There's scope for optimization there. Go used 8mb of ram, whereas java was sitting on 130mb after a few runs. The Java version, cranking out at 10kr/s was maxing the kernel out on one core, so that's probably approaching the practical limit for single machine tests. I suspect putting a load balancer in front of a couple of instances of the go program would allow you to totally smash the java performance, given that it lit 2 cores at 6kr/s, and java lit 8 at 10kr/s. The memory usage tradeoff is significant - JVM sitting at 130mb and Go sitting at 8mb. Clearly everyone needs to draw their own conclusions on this, for their own purposes. The JVM solution is carrying a stats server, a ton of other tooling and so on. The Go system has some - pprof was included, but it's limited by comparison. Arguably gdb and so on can actually be of real use in the Go case, but that's also an exercise for the reader. Interesting any which way you look at it. There are a lot of other interesting side effects (that need working out) in both programs as evidenced by this simple testing. Postgres also needs some tuning if you really want to slam this with anything remotely resembling a real world scale test. My tests were done on OSX 10.8 12B19 on a 2.3GHz i7 wiht 8GB of DDR3 at 1333MHz, an intel 510 SSD, totally untuned postgres. The machine is a Macbook from whatever year that is. Here's wrk, for anyone looking for it: https://github.com/wg/wrk
In Comparing Go and Java, Part 2 – Performance

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