mirror of
https://git.haproxy.org/git/haproxy.git/
synced 2025-10-26 22:20:59 +01:00
03e9a5a1e7
A subtle regression was introduced in 3.0 by commit faa8c3e02 ("MEDIUM:
lb-chash: Deterministic node hashes based on server address"). When keys
are calculated from the server's ID (which is the default), due to the
reorganisation of the code, the key ended up being hashed twice instead
of being multiplied by the scaling range.
While most users will never notice it, it is blocking some large cache
users from upgrading from 2.8 to 3.0 or 3.2 because the keys are
redistributed.
After a check with users on the mailing list [1] it was estimated that
keep the current situation is the worst choice because those who have
not yet upgraded will face the problem while by fixing it, those who
already have and for whom it happened smoothly will handle it just
right again.
As such this fix must be backported to 3.0 without waiting (in order
to preserve those who upgrade from two redistributions). Please note
that only configurations featuring "hash-type consistent" and not
having "hash-key" present with a value other than "id" are affected,
others are not (e.g. "hash-key addr" is unaffected).
[1] https://www.mail-archive.com/haproxy@formilux.org/msg46115.html
* Regression testing for HAProxy with VTest *
This little README file is about how to compile and run vtest test case files (VTC files)
to test HAProxy for any regression.
To do so, you will have to compile vtest program sources which depends on
Varnish cache application sources. vtest, formerly varnishtest, is a very useful
program which has been developed to test Varnish cache application. vtest has been
modified in collaboration with Varnish cache conceptor Poul-Henning Kamp to support
HAProxy in addition to Varnish cache.
See also: doc/regression-testing.txt
* vtest compilation *
$ git clone https://github.com/vtest/VTest2
$ cd VTest
$ make vtest
Then vtest program may be found at the root directory of vtest sources directory.
The Varnish cache manuals are located in 'man' directory of Varnish cache sources
directory. You will have to have a look at varnishtest(7) and vtc(7) manuals to
use vtest.
Some information may also be found in doc/regression-testing.txt in HAProxy
sources.
Note that VTC files for Varnish cache may be found in bin/varnishtest/tests directory
of Varnish cache sources directory which may be found here:
https://github.com/varnishcache/varnish-cache
* vtest execution *
You must set HAPROXY_PROGRAM environment variable to give the location
of the HAProxy program to test to vtest:
$ HAPROXY_PROGRAM=<my haproxy program> vtest ...
The HAProxy VTC files found in HAProxy sources may be run with the reg-tests
Makefile target. You must set the VTEST_PROGRAM environment variable to
give the location of the vtest program which has been previously compiled.
$ VTEST_PROGRAM=<my vtest program> make reg-tests
"reg-tests" Makefile target run scripts/run-regtest.sh script.
To get more information about this script run it with --help option.
Note that vtest is run with -t10 and -l option. -l option is to keep
keep vtest temporary directory in case of failed test cases. core files
may be found in this directory (if enabled by ulimit).
* vtest patches for HAProxy VTC files *
When producing a patch to add a VTC regression testing file to reg-tests directory,
please follow these simple rules:
- If your VTC file needs others files, if possible, use the same basename as that
of the VTC file,
- Put these files in a directory with the same name as the code area concerned
by the bug ('peers', 'lua', 'acl' etc).
Please note that most tests use a common set of timeouts defined by the
environment variable HAPROXY_TEST_TIMEOUT. As much as possible, for regular I/O
(i.e. not errors), please try to reuse that setting so that the value may
easily be adjusted when running in some particularly slow environments, or be
shortened to fail faster on developers' machines.