On Wed, Oct 7, 2015 at 4:16 PM, Amir Rohan <amir.rohan@zoho.com> wrote:
> On 10/07/2015 09:27 AM, Michael Paquier wrote:
>> On Wed, Oct 7, 2015 at 7:51 AM, Michael Paquier
>> <michael.paquier@gmail.com> wrote:
>>> On Wed, Oct 7, 2015 at 7:43 AM, Michael Paquier
>>> <michael.paquier@gmail.com> wrote:
>>>> On Wed, Oct 7, 2015 at 5:58 AM, Robert Haas wrote:
>>>>> On Sat, Oct 3, 2015 at 7:38 AM, Michael Paquier wrote:
>>>>> It seems that these days 'make check' creates a directory in /tmp
>>>>> called /tmp/pg_regress-RANDOMSTUFF. Listening on TCP ports is
>>>>> disabled, and the socket goes inside this directory with a name like
>>>>> .s.PGSQL.PORT. You can connect with psql -h
>>>>> /tmp/pg_regress-RANDOMSTUFF -p PORT, but not over TCP. This basically
>>>>> removes the risk of TCP port number collisions, as well as the risk of
>>>>> your temporary instance being hijacked by a malicious user on the same
>>>>> machine.
>>>>
>>>> Right, that's for example /var/folders/ on OSX, and this is defined
>>>> once per test run via $tempdir_short. PGHOST is set to that as well.
>>>
>>> Er, mistake here. That's actually once per standard_initdb, except
>>> that all the tests I have included in my patch run it just once to
>>> create a master node. It seems that it would be wiser to set one
>>> socket dir per node then, remove the port assignment stuff, and use
>>> tempdir_short as a key to define a node as well as in the connection
>>> string to this node. I'll update the patch later today...
>>
>> So, my conclusion regarding multiple calls of make_master is that we
>> should not allow to do it. On Unix/Linux we could have a separate unix
>> socket directory for each node, but not on Windows where
>> listen_addresses is set to look after 127.0.0.1. On Unix/Linux, PGHOST
>> is set by the master node to a tempdir once and for all. Hence, to
>> make the code more consistent, I think that we should keep the port
>> lookup machinery here. An updated patch is attached.
>>
> If parallel tests are supported, get_free_port is still racy even
> with last_port_found because it's:
> 1) process-local.
> 2) even if it were shared, there's the race window between the
> available-check and the listen() I mentioned upthread.
>
> If parallel tests are explicitly disallowed, a comment to that
> effect (and a note on things known to break) might help someone
> down the road.
Actually, no, port lookup will not map and parallel tests would work
fine thinking more about it, each set of tests uses its own PGHOST to
a private unix socket directory so even if multiple tests use the same
port number they won't interact with each other because they connect
to different socket paths. MinGW is a problem though, and an existing
one in the perl test scripts, I recall that it can use make -j and
that's on Windows where PGHOST is mapping to 127.0.0.1 only.
> Also, the removal of poll_query_until from pg_rewind looks suspiciously
> like a copy-paste gone bad. Pardon if I'm missing something.
Perhaps. Do you have a suggestion regarding that? It seems to me that
this is more useful in TestLib.pm as-is.
--
Michael
