tests/functional: Make socat wait longer in migration exec test

[PATCH v1] tests/functional: Make socat wait longer in migration exec test

Posted by Fabiano Rosas 1 month, 1 week ago

The migration_with_exec test is failing sporadically for all
architectures due to a race when the destination socat process takes
too long to start listening while the source process is already
issuing connect().

The race is inherent because the exec: migration spawns the
to-be-exec'ed command asynchronously and returns from the
migrate-incoming command. The localhost-only testcase is not
representative of the majority of migrations. In a real scenario
between two different hosts that race wouldn't happen.

Fix the testcase by configuring the source socat command to wait
indefinitely while trying to connect.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 tests/functional/migration.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/functional/migration.py b/tests/functional/migration.py
index 144f091ba8..3b7674af3b 100644
--- a/tests/functional/migration.py
+++ b/tests/functional/migration.py
@@ -85,5 +85,5 @@ def migration_with_exec(self):
         with Ports() as ports:
             free_port = self._get_free_port(ports)
             dst_uri = 'exec:socat TCP-LISTEN:%u -' % free_port
-            src_uri = 'exec:socat - TCP:localhost:%u' % free_port
+            src_uri = 'exec:socat - TCP:localhost:%u,forever' % free_port
             self.migrate(dst_uri, src_uri)
-- 
2.51.0

Re: [PATCH v1] tests/functional: Make socat wait longer in migration exec test

Posted by Thomas Huth 1 month, 1 week ago

On 23/04/2026 01.00, Fabiano Rosas wrote:
> The migration_with_exec test is failing sporadically for all
> architectures due to a race when the destination socat process takes
> too long to start listening while the source process is already
> issuing connect().
> 
> The race is inherent because the exec: migration spawns the
> to-be-exec'ed command asynchronously and returns from the
> migrate-incoming command. The localhost-only testcase is not
> representative of the majority of migrations. In a real scenario
> between two different hosts that race wouldn't happen.
> 
> Fix the testcase by configuring the source socat command to wait
> indefinitely while trying to connect.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>   tests/functional/migration.py | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/functional/migration.py b/tests/functional/migration.py
> index 144f091ba8..3b7674af3b 100644
> --- a/tests/functional/migration.py
> +++ b/tests/functional/migration.py
> @@ -85,5 +85,5 @@ def migration_with_exec(self):
>           with Ports() as ports:
>               free_port = self._get_free_port(ports)
>               dst_uri = 'exec:socat TCP-LISTEN:%u -' % free_port
> -            src_uri = 'exec:socat - TCP:localhost:%u' % free_port
> +            src_uri = 'exec:socat - TCP:localhost:%u,forever' % free_port

Maybe use "retry=90" instead? OTOH, we have the high level timeout from the 
meson runner, so we should not hang here forever by accident anyway.

Thus:
Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [PATCH v1] tests/functional: Make socat wait longer in migration exec test

Posted by Peter Xu 1 month, 1 week ago

On Thu, Apr 23, 2026 at 06:52:19AM +0200, Thomas Huth wrote:
> On 23/04/2026 01.00, Fabiano Rosas wrote:
> > The migration_with_exec test is failing sporadically for all
> > architectures due to a race when the destination socat process takes
> > too long to start listening while the source process is already
> > issuing connect().
> > 
> > The race is inherent because the exec: migration spawns the
> > to-be-exec'ed command asynchronously and returns from the
> > migrate-incoming command. The localhost-only testcase is not
> > representative of the majority of migrations. In a real scenario
> > between two different hosts that race wouldn't happen.
> > 
> > Fix the testcase by configuring the source socat command to wait
> > indefinitely while trying to connect.
> > 
> > Signed-off-by: Fabiano Rosas <farosas@suse.de>
> > ---
> >   tests/functional/migration.py | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tests/functional/migration.py b/tests/functional/migration.py
> > index 144f091ba8..3b7674af3b 100644
> > --- a/tests/functional/migration.py
> > +++ b/tests/functional/migration.py
> > @@ -85,5 +85,5 @@ def migration_with_exec(self):
> >           with Ports() as ports:
> >               free_port = self._get_free_port(ports)
> >               dst_uri = 'exec:socat TCP-LISTEN:%u -' % free_port
> > -            src_uri = 'exec:socat - TCP:localhost:%u' % free_port
> > +            src_uri = 'exec:socat - TCP:localhost:%u,forever' % free_port
> 
> Maybe use "retry=90" instead? OTOH, we have the high level timeout from the
> meson runner, so we should not hang here forever by accident anyway.

Yes, IMHO it'll be good to stick with one timeout mechanism rather than
adding more magical timeouts.

> 
> Thus:
> Reviewed-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu

Re: [PATCH v1] tests/functional: Make socat wait longer in migration exec test

Posted by Philippe Mathieu-Daudé 1 month, 1 week ago

On 23/4/26 17:02, Peter Xu wrote:
> On Thu, Apr 23, 2026 at 06:52:19AM +0200, Thomas Huth wrote:
>> On 23/04/2026 01.00, Fabiano Rosas wrote:
>>> The migration_with_exec test is failing sporadically for all
>>> architectures due to a race when the destination socat process takes
>>> too long to start listening while the source process is already
>>> issuing connect().
>>>
>>> The race is inherent because the exec: migration spawns the
>>> to-be-exec'ed command asynchronously and returns from the
>>> migrate-incoming command. The localhost-only testcase is not
>>> representative of the majority of migrations. In a real scenario
>>> between two different hosts that race wouldn't happen.
>>>
>>> Fix the testcase by configuring the source socat command to wait
>>> indefinitely while trying to connect.
>>>
>>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>>> ---
>>>    tests/functional/migration.py | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/tests/functional/migration.py b/tests/functional/migration.py
>>> index 144f091ba8..3b7674af3b 100644
>>> --- a/tests/functional/migration.py
>>> +++ b/tests/functional/migration.py
>>> @@ -85,5 +85,5 @@ def migration_with_exec(self):
>>>            with Ports() as ports:
>>>                free_port = self._get_free_port(ports)
>>>                dst_uri = 'exec:socat TCP-LISTEN:%u -' % free_port
>>> -            src_uri = 'exec:socat - TCP:localhost:%u' % free_port
>>> +            src_uri = 'exec:socat - TCP:localhost:%u,forever' % free_port
>>
>> Maybe use "retry=90" instead? OTOH, we have the high level timeout from the
>> meson runner, so we should not hang here forever by accident anyway.
> 
> Yes, IMHO it'll be good to stick with one timeout mechanism rather than
> adding more magical timeouts.
> 
>>
>> Thus:
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
> 
> Reviewed-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>