[petsc-users] osx error
Barry Smith
bsmith at petsc.dev
Fri Sep 18 10:42:35 CDT 2020
> On Sep 18, 2020, at 10:14 AM, Satish Balay <balay at mcs.anl.gov> wrote:
>
> Its probably better to just run a test with gethostbyname()?
I had hoped to avoid building C code and running it. The Apple manual page for gethostbyname() states: The getaddrinfo(3) and getnameinfo(3) functions are preferred over the gethostbyname(), gethostbyname2(), and
gethostbyaddr() functions.
I do not know what MPICH and OpenMPI use.
On the Mac
>
> The closest thing I can think off is:
>
>
> I don't know if 'traceroute' or 'host' commands are universally available.
>
>>>>>>>
> balay at sb /home/balay
> $ host `hostname`
> sb has address 192.168.0.144
$ host `hostname`
Host Barrys-MacBook-Pro-3.local not found: 3(NXDOMAIN)
Also on the Apple `hostname` is associated with multiple addresses and it seems different utilities may use different addresses produced. Some addresses may work, others may not.
I will make one more MR adding traceroute first and if any of the tests succeed continue. If that fails for users then we will likely need to drop the test.
I don't like just using a mpiexec -n 2 test because that can fail for so many reasons it is difficult to provide diagnostics to the users.
Barry
> balay at sb /home/balay
> $ echo $?
> 0
> balay at sb /home/balay
> $ host foobar
> Host foobar not found: 3(NXDOMAIN)
> balay at sb /home/balay
> $ echo $?
> 1
> balay at sb /home/balay
> $
> <<<<<<
>
> However - I fear if there are *any* false positives - or false negatives - this test will generate more e-mail than the actual issue [of misbehaving MPI]
>
> Satish
>
> On Fri, 18 Sep 2020, Barry Smith wrote:
>
>>
>> try
>>
>> /usr/sbin/traceroute `hostname`
>>
>>
>>> On Sep 18, 2020, at 10:07 AM, Mark Adams <mfadams at lbl.gov> wrote:
>>>
>>> Let me know if you want anything else.
>>> Thanks,
>>> Mark
>>>
>>> On Fri, Sep 18, 2020 at 11:05 AM Mark Adams <mfadams at lbl.gov <mailto:mfadams at lbl.gov>> wrote:
>>>
>>>
>>> On Fri, Sep 18, 2020 at 11:04 AM Satish Balay <balay at mcs.anl.gov <mailto:balay at mcs.anl.gov>> wrote:
>>> On Fri, 18 Sep 2020, Satish Balay via petsc-users wrote:
>>>
>>>>>>> 07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local
>>>>>>> PING marksmac-302.local (127.0.0.1): 56 data bytes
>>>>
>>>> So it is resolving MarksMac-302.local as 127.0.0.1 - but ping is not responding?
>>>>
>>>> I know some machines don't respond to external ping [and firewalls can block it] but don't really know if they always respond to internal ping or not.
>>>>
>>>> If some machines don't respond to internal ping - then we can't use ping test in configure [it will create false negatives - as in this case]
>>>
>>> BTW: To confirm, please try:
>>>
>>> ping 127.0.0.1
>>>
>>>
>>> 11:02 master *= ~/Codes/petsc$ sudo vi /etc/hosts
>>> 11:02 master *= ~/Codes/petsc$ ping 127.0.0.1
>>> PING 127.0.0.1 (127.0.0.1): 56 data bytes
>>> Request timeout for icmp_seq 0
>>> Request timeout for icmp_seq 1
>>> Request timeout for icmp_seq 2
>>> Request timeout for icmp_seq 3
>>> Request timeout for icmp_seq 4
>>> Request timeout for icmp_seq 5
>>> Request timeout for icmp_seq 6
>>> Request timeout for icmp_seq 7
>>> Request timeout for icmp_seq 8
>>> Request timeout for icmp_seq 9
>>> Request timeout for icmp_seq 10
>>> Request timeout for icmp_seq 11
>>> Request timeout for icmp_seq 12
>>> Request timeout for icmp_seq 13
>>> Request timeout for icmp_seq 14
>>> Request timeout for icmp_seq 15
>>> Request timeout for icmp_seq 16
>>> Request timeout for icmp_seq 17
>>> Request timeout for icmp_seq 18
>>> Request timeout for icmp_seq 19
>>> Request timeout for icmp_seq 20
>>> Request timeout for icmp_seq 21
>>>
>>> still going ......
>>>
>>>
>>> Satish
>>>
>>>>
>>>>
>>>> Mark, can you remove the line that you added to /etc/hosts - i.e:
>>>>
>>>> 127.0.0.1 MarksMac-302.local
>>>>
>>>> And now rerun MPI tests. Do they work or fail?
>>>>
>>>> [this is to check if this test is a false positive on your machine]
>>>>
>>>> Satish
>>>>
>>>>
>>>> On Fri, 18 Sep 2020, Mark Adams wrote:
>>>>
>>>>> On Fri, Sep 18, 2020 at 7:51 AM Matthew Knepley <knepley at gmail.com <mailto:knepley at gmail.com>> wrote:
>>>>>
>>>>>> On Fri, Sep 18, 2020 at 7:46 AM Mark Adams <mfadams at lbl.gov <mailto:mfadams at lbl.gov>> wrote:
>>>>>>
>>>>>>> Oh you did not change my hostname:
>>>>>>>
>>>>>>> 07:37 master *= ~/Codes/petsc$ hostname
>>>>>>> MarksMac-302.local
>>>>>>> 07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local
>>>>>>> PING marksmac-302.local (127.0.0.1): 56 data bytes
>>>>>>> Request timeout for icmp_seq 0
>>>>>>>
>>>>>>> --- marksmac-302.local ping statistics ---
>>>>>>> 2 packets transmitted, 0 packets received, 100.0% packet loss
>>>>>>> 07:42 2 master *= ~/Codes/petsc$
>>>>>>>
>>>>>>
>>>>>> This does not make sense to me. You have
>>>>>>
>>>>>> 127.0.0.1 MarksMac-302.local
>>>>>>
>>>>>> in /etc/hosts,
>>>>>>
>>>>>
>>>>> 09:07 ~/.ssh$ cat /etc/hosts
>>>>> ##
>>>>> # Host Database
>>>>> #
>>>>> # localhost is used to configure the loopback interface
>>>>> # when the system is booting. Do not change this entry.
>>>>> ##
>>>>> 127.0.0.1 localhost
>>>>> 255.255.255.255 broadcasthost
>>>>> 127.0.0.1 MarksMac-5.local
>>>>> 127.0.0.1 243.124.240.10.in-addr.arpa.private.cam.ac.uk <http://243.124.240.10.in-addr.arpa.private.cam.ac.uk/>
>>>>> 127.0.0.1 MarksMac-302.local
>>>>> 09:07 ~/.ssh$
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> but you cannot resolve that name?
>>>>>>
>>>>>> Matt
>>>>>>
>>>>>>
>>>>>>> BTW, I used to get messages about some network issue and 'changing host
>>>>>>> name to MarksMac-[x+1].local'. That is, the original hostname
>>>>>>> was MarksMac.local, then I got a message about changing
>>>>>>> to MarksMac-1.local, etc. I have not seen these messages for months but
>>>>>>> apparently this process has continued unabated.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Sep 17, 2020 at 11:10 PM Satish Balay via petsc-users <
>>>>>>> petsc-users at mcs.anl.gov <mailto:petsc-users at mcs.anl.gov>> wrote:
>>>>>>>
>>>>>>>> On Thu, 17 Sep 2020, Matthew Knepley wrote:
>>>>>>>>
>>>>>>>>> On Thu, Sep 17, 2020 at 8:33 PM Barry Smith <bsmith at petsc.dev <mailto:bsmith at petsc.dev>> wrote:
>>>>>>>>>
>>>>>>>>>>> On Sep 17, 2020, at 4:59 PM, Satish Balay via petsc-users <
>>>>>>>>>> petsc-users at mcs.anl.gov <mailto:petsc-users at mcs.anl.gov>> wrote:
>>>>>>>>>>>
>>>>>>>>>>> Here is a fix:
>>>>>>>>>>>
>>>>>>>>>>> echo 127.0.0.1 `hostname` | sudo tee -a /etc/hosts
>>>>>>>>>>
>>>>>>>>>> Satish,
>>>>>>>>>>
>>>>>>>>>> I don't think you want to be doing this on a Mac (on anything?)
>>>>>>>> On a
>>>>>>>>>> Mac based on the network configuration etc as it boots up and as
>>>>>>>> networks
>>>>>>>>>> are accessible or not (wi-fi) it determines what hostname should be,
>>>>>>>> one
>>>>>>>>>> should never being hardwiring it to some value.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Satish is just naming the loopback interface. I did this on all my
>>>>>>>> former
>>>>>>>>> Macs.
>>>>>>>>
>>>>>>>>
>>>>>>>> Yes - this doesn't change the hostname. Its just adding an entry for
>>>>>>>> gethostbyname - for current hostname.
>>>>>>>>
>>>>>>>>>>>
>>>>>>>> 127.0.0.1 MarksMac-302.local
>>>>>>>> <<<
>>>>>>>>
>>>>>>>> Sure - its best to not do this when one has a proper IP name [like
>>>>>>>> foo.mcs.anl.gov <http://foo.mcs.anl.gov/>] - but its useful when one has a hostname like
>>>>>>>> "MarksMac-302.local" -that is not DNS resolvable
>>>>>>>>
>>>>>>>> Even if the machine is moved to a different network with a different
>>>>>>>> name - the current entry won't cause problems [but will need another entry
>>>>>>>> for the new host name - if this new name is also not DNS resolvable]
>>>>>>>>
>>>>>>>> Its likely this file is a generated file on macos - so might get reset
>>>>>>>> on reboot - or some network change? [if this is the case - the change won't
>>>>>>>> be permanent]
>>>>>>>>
>>>>>>>>
>>>>>>>> Satish
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> What most experimenters take for granted before they begin their
>>>>>> experiments is infinitely more interesting than any results to which their
>>>>>> experiments lead.
>>>>>> -- Norbert Wiener
>>>>>>
>>>>>> https://www.cse.buffalo.edu/~knepley/ <https://www.cse.buffalo.edu/~knepley/>
>>>>>> <http://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>>
>>>>>>
>>>>>
>>>>
>>>
>>
>>
>
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