[SRU] wrk fails to run

[Juanjo Aparicio]

[ Impact ]

wrk is completely unusable as it will fail to run with the following error when tried to benchmark the http server:

$ wrk http://localhost/
PANIC: unprotected error in call to Lua API (attempt to index a nil value)

[ Test Plan ]

wrk is a http benchmarking tool and can be used to benchmark servers.

* Test with a local server:
  - Install wrk and apache2
  - execute "wrk http://127.0.0.1/"
  - It should show result like:

$ wrk http://127.0.0.1
Running 10s test @ http://127.0.0.1
  2 threads and 10 connections
  Thread Stats Avg Stdev Max +/- Stdev
    Latency 252.68us 396.44us 4.85ms 91.09%
    Req/Sec 33.23k 4.37k 43.34k 70.00%
  661179 requests in 10.00s, 6.73GB read
Requests/sec: 66114.70
Transfer/sec: 688.92MB

* Test with remote server:
  - Install wrk
  - execute "wrk https://ubuntu.com/"
  - It should show results like:

$ wrk https://ubuntu.com/
Running 10s test @ https://ubuntu.com/
  2 threads and 10 connections
  Thread Stats Avg Stdev Max +/- Stdev
    Latency 53.19ms 117.13ms 1.28s 95.87%
    Req/Sec 148.63 34.23 220.00 70.50%
  2964 requests in 10.01s, 293.91MB read
Requests/sec: 296.04
Transfer/sec: 29.36MB

[ Where problems could occur ]

This is not changing anything, is just a rebuild which Ubuntu missed for some reason. Debian has done the rebuild as '4.1.0-3+b2' for the libluajit transition. And, the chances of regression because of the rebuild is almost nil.

[ Other Info ]

Just for fun, I tried to do a benchmark of google.com also for a comparison with ubuntu.com benchmarking result.

$ wrk https://google.com
Running 10s test @ https://google.com
  2 threads and 10 connections
  Thread Stats Avg Stdev Max +/- Stdev
    Latency 187.83ms 175.23ms 949.07ms 81.17%
    Req/Sec 37.29 55.67 202.00 84.62%
  598 requests in 10.03s, 650.20KB read
Requests/sec: 59.62
Transfer/sec: 64.83KB

[ Original Bug Description ]

Running wrk 4.1.0-3build1 against a web server fails:

bnt@workstation:~$ wrk http://localhost/
PANIC: unprotected error in call to Lua API (attempt to index a nil value)

I'm running Ubuntu 23.04.

Running wrk with no options shows the help info:

bnt@workstation:~$ wrk
Usage: wrk <options> <url>
  Options:
    -c, --connections <N> Connections to keep open
    -d, --duration <T> Duration of test
    -t, --threads <N> Number of threads to use

    -s, --script <S> Load Lua script file
    -H, --header <H> Add header to request
        --latency Print latency statistics
        --timeout <T> Socket/request timeout
    -v, --version Print version details

  Numeric arguments may include a SI unit (1k, 1M, 1G)
  Time arguments may include a time unit (2s, 2m, 2h)

ldd shows wrk relies on libluajit-5.1.so.2, which is installed:

bnt@workstation:~$ ldd /usr/bin/wrk
 linux-vdso.so.1 (0x00007ffe049a4000)
 libluajit-5.1.so.2 => /lib/x86_64-linux-gnu/libluajit-5.1.so.2 (0x00007f30f0321000)
 libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f30f0238000)
 libssl.so.3 => /lib/x86_64-linux-gnu/libssl.so.3 (0x00007f30f0193000)
 libcrypto.so.3 => /lib/x86_64-linux-gnu/libcrypto.so.3 (0x00007f30efc00000)
 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f30ef800000)
 libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f30f016d000)
 /lib64/ld-linux-x86-64.so.2 (0x00007f30f03fe000)

bnt@workstation:~$ dpkg --list libluajit*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=====================-================================-============-============================>
ii libluajit-5.1-2:amd64 2.1.0~beta3+git20220320+dfsg-4.1 amd64 Just in time compiler for Lu>
ii libluajit-5.1-common 2.1.0~beta3+git20220320+dfsg-4.1 all Just in time compiler for Lu>
un libluajit2-5.1-2 <none> <none> (no description available)
un libluajit2-5.1-common <none> <none> (no description available)

[Juanjo Aparicio (bnt)]

I downloaded the package sources via

    apt-get download wrk

then proceeded to build the package with

    dpkg-buildpackage -us -uc

The process complained about missing libraries, libluajit-5.1-dev if I recall correctly. Installing it allowed me to build the package.

Installing the generated package results in a wrk binary that actually works.

[Juanjo Aparicio (bnt)]

Additional info: the package wrk 4.1.0-3build1 on Ubuntu 22.04.02 LTS *does* work correctly.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sudip Mukherjee (sudipmuk)]

I can confirm that the issue is seen on Mantic. Also tested and confirmed Jammy and Noble are not affected.

[Sudip Mukherjee (sudipmuk)]

debdiff attached for Mantic.

[Lena Voytek (lvoytek)]

sponsored the no change rebuild

[Timo Aaltonen (tjaalton)]

Hello Juanjo, or anyone else affected,

Accepted wrk into mantic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/wrk/4.1.0-3build2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-mantic to verification-done-mantic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-mantic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Juanjo Aparicio (bnt)]

I can confirm the proposed package fixes the issue for me.

Just upgraded to

ii wrk 4.1.0-3build2 amd64 HTTP benchmarking tool

Tested against the following webservers:

* localhost

bnt@workstation:~$ wrk http://localhost/
Running 10s test @ http://localhost/
  2 threads and 10 connections
  Thread Stats Avg Stdev Max +/- Stdev
    Latency 509.81us 4.59ms 86.87ms 99.17%
    Req/Sec 35.11k 5.34k 42.95k 82.50%
  698425 requests in 10.00s, 7.65GB read
Requests/sec: 69835.52
Transfer/sec: 783.22MB

* different host on the same LAN

bnt@workstation:~$ wrk http://www.fastpace.org/
Running 10s test @ http://www.fastpace.org/
  2 threads and 10 connections
  Thread Stats Avg Stdev Max +/- Stdev
    Latency 136.95us 27.55us 1.03ms 73.95%
    Req/Sec 35.24k 1.51k 38.68k 71.64%
  704908 requests in 10.10s, 314.61MB read
Requests/sec: 69797.92
Transfer/sec: 31.15MB

* Internet host

bnt@workstation:~$ wrk http://www.google.com/
Running 10s test @ http://www.google.com/
  2 threads and 10 connections
  Thread Stats Avg Stdev Max +/- Stdev
    Latency 441.69ms 61.96ms 774.67ms 75.00%
    Req/Sec 13.25 8.47 40.00 80.77%
  220 requests in 10.02s, 11.25MB read
Requests/sec: 21.96
Transfer/sec: 1.12MB

[Launchpad Janitor (janitor)]

This bug was fixed in the package wrk - 4.1.0-3build2

---------------
wrk (4.1.0-3build2) mantic; urgency=medium

  * No-change rebuild to pick up alternative libluajit2
    dependency. (LP: #2026760)

 -- Sudip Mukherjee <email address hidden> Mon, 19 Feb 2024 20:34:42 +0000

[Chris Halse Rogers (raof)]

The verification of the Stable Release Update for wrk has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.