Re: ssl tests fail due to TCP port conflict

On 2024-06-06 Th 18:02, Jelte Fennema-Nio wrote:
> On Wed, 5 Jun 2024 at 23:37, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Andrew Dunstan <andrew@dunslane.net> writes:
>>> On 2024-06-05 We 16:00, Alexander Lakhin wrote:
>>>> That is, psql from the test instance 001_ssltests_34 opened a
>>>> connection to
>>>> the test server with the client port 50072 and it made using the port by
>>>> the server from the test instance 001_ssltests_30 impossible.
>>> Oh. (kicks self)
>> D'oh.
>>
>>> Should we really be allocating ephemeral server ports in the range
>>> 41952..65535? Maybe we should be looking for an unallocated port
>>> somewhere below 41952, and above, say, 32767, so we couldn't have a
>>> client socket collision.
>> Hmm, are there really any standards about how these port numbers
>> are used?
>>
>> I wonder if we don't need to just be prepared to retry the whole
>> thing a few times.  Even if it's true that "clients" shouldn't
>> choose ports below 41952, we still have a small chance of failure
>> against a non-Postgres server starting up at the wrong time.
> My suggestion would be to not touch the ephemeral port range at all
> for these ports. In practice the ephemeral port range is used for
> cases where the operating system assigns the port, and the application
> doesn't care whot it is. Not for when you want to get a free port, but
> want to know in advance which one it is.
>
> For the PgBouncer test suite we do something similar as the PG its
> perl tests do, but there we allocate a port between 10200 and 32768:
> https://github.com/pgbouncer/pgbouncer/blob/master/test/utils.py#L192-L215
>
> Sure theoretically it's possible to hit a rare case where another
> server starts up at the wrong time, but that chance seems way lower
> than a client starting up at the wrong time. Especially since there
> aren't many servers that use a port with 5 digits.
>
> Attached is a patch that updates the port numbers.


Makes sense to me.

I still think my patch to force TCP mode for the SSL test makes sense as 
well.


cheers


andrew


--
Andrew Dunstan
EDB: https://www.enterprisedb.com