[PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Feng Yang]

If a connection and stdin are idle for more than timeout seconds,
then the connection is silently closed. withou this paramter,
nc will listen forever for a connection. This may cause our test
hang. redmine issue:
http://redmine.englab.nay.redhat.com/issues/show/6947
Add -w parameter should fix this issue.

Signed-off-by: Feng Yang <fyang@redhat.com>
---
 client/tests/kvm/kvm_utils.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/client/tests/kvm/kvm_utils.py b/client/tests/kvm/kvm_utils.py
index a51c857..526d38d 100644
--- a/client/tests/kvm/kvm_utils.py
+++ b/client/tests/kvm/kvm_utils.py
@@ -733,7 +733,7 @@ def remote_login(client, host, port, username, password, prompt, linesep="\n",
     elif client == "telnet":
         cmd = "telnet -l %s %s %s" % (username, host, port)
     elif client == "nc":
-        cmd = "nc %s %s" % (host, port)
+        cmd = "nc %s %s -w %s" % (host, port, timeout)
     else:
         logging.error("Unknown remote shell client: %s" % client)
         return
-- 
1.6.5.2

Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Michael Goldish]

On 10/20/2010 08:55 AM, Feng Yang wrote:
> If a connection and stdin are idle for more than timeout seconds,
> then the connection is silently closed. withou this paramter,
> nc will listen forever for a connection. This may cause our test
> hang. redmine issue:
> http://redmine.englab.nay.redhat.com/issues/show/6947
> Add -w parameter should fix this issue.
> 
> Signed-off-by: Feng Yang <fyang@redhat.com>
> ---
>  client/tests/kvm/kvm_utils.py |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/client/tests/kvm/kvm_utils.py b/client/tests/kvm/kvm_utils.py
> index a51c857..526d38d 100644
> --- a/client/tests/kvm/kvm_utils.py
> +++ b/client/tests/kvm/kvm_utils.py
> @@ -733,7 +733,7 @@ def remote_login(client, host, port, username, password, prompt, linesep="\n",
>      elif client == "telnet":
>          cmd = "telnet -l %s %s %s" % (username, host, port)
>      elif client == "nc":
> -        cmd = "nc %s %s" % (host, port)
> +        cmd = "nc %s %s -w %s" % (host, port, timeout)
>      else:
>          logging.error("Unknown remote shell client: %s" % client)
>          return

I don't understand how remote_login() can stall here.
kvm_utils._remote_login() doesn't rely on nc's self-termination.  If no
shell prompt is available after 10 seconds, nc is forcefully terminated
and _remote_login() fails.  If it somehow stalls this might indicate a
bug somewhere.

Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Feng Yang]

----- "Michael Goldish" <mgoldish@redhat.com> wrote:

> From: "Michael Goldish" <mgoldish@redhat.com>
> To: "Feng Yang" <fyang@redhat.com>
> Cc: autotest@test.kernel.org, kvm@vger.kernel.org
> Sent: Wednesday, October 20, 2010 5:11:32 PM GMT +08:00 Beijing / Chongqing / Hong Kong / Urumqi
> Subject: Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py
>
> On 10/20/2010 08:55 AM, Feng Yang wrote:
> > If a connection and stdin are idle for more than timeout seconds,
> > then the connection is silently closed. withou this paramter,
> > nc will listen forever for a connection. This may cause our test
> > hang. redmine issue:
> > http://redmine.englab.nay.redhat.com/issues/show/6947
> > Add -w parameter should fix this issue.
> > 
> > Signed-off-by: Feng Yang <fyang@redhat.com>
> > ---
> >  client/tests/kvm/kvm_utils.py |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/client/tests/kvm/kvm_utils.py
> b/client/tests/kvm/kvm_utils.py
> > index a51c857..526d38d 100644
> > --- a/client/tests/kvm/kvm_utils.py
> > +++ b/client/tests/kvm/kvm_utils.py
> > @@ -733,7 +733,7 @@ def remote_login(client, host, port, username,
> password, prompt, linesep="\n",
> >      elif client == "telnet":
> >          cmd = "telnet -l %s %s %s" % (username, host, port)
> >      elif client == "nc":
> > -        cmd = "nc %s %s" % (host, port)
> > +        cmd = "nc %s %s -w %s" % (host, port, timeout)
> >      else:
> >          logging.error("Unknown remote shell client: %s" % client)
> >          return
> 
> I don't understand how remote_login() can stall here.
> kvm_utils._remote_login() doesn't rely on nc's self-termination.  If
> no
> shell prompt is available after 10 seconds, nc is forcefully
> terminated
> and _remote_login() fails.  If it somehow stalls this might indicate
> a
> bug somewhere.
It is really rarely reproduce. Only meet this issue when guest panic or core dump.
nc stall. Do not know why it is not terminated after 10s.

I think -w parameter is helpful in this situation.
If it does not cause other issue,  we'd better add -w in nc command.

Thanks for your command. What do you think?

Feng Yang

Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Michael Goldish]

On 10/20/2010 12:18 PM, Feng Yang wrote:
> 
> ----- "Michael Goldish" <mgoldish@redhat.com> wrote:
> 
>> From: "Michael Goldish" <mgoldish@redhat.com>
>> To: "Feng Yang" <fyang@redhat.com>
>> Cc: autotest@test.kernel.org, kvm@vger.kernel.org
>> Sent: Wednesday, October 20, 2010 5:11:32 PM GMT +08:00 Beijing / Chongqing / Hong Kong / Urumqi
>> Subject: Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py
>>
>> On 10/20/2010 08:55 AM, Feng Yang wrote:
>>> If a connection and stdin are idle for more than timeout seconds,
>>> then the connection is silently closed. withou this paramter,
>>> nc will listen forever for a connection. This may cause our test
>>> hang. redmine issue:
>>> http://redmine.englab.nay.redhat.com/issues/show/6947
>>> Add -w parameter should fix this issue.
>>>
>>> Signed-off-by: Feng Yang <fyang@redhat.com>
>>> ---
>>>  client/tests/kvm/kvm_utils.py |    2 +-
>>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/client/tests/kvm/kvm_utils.py
>> b/client/tests/kvm/kvm_utils.py
>>> index a51c857..526d38d 100644
>>> --- a/client/tests/kvm/kvm_utils.py
>>> +++ b/client/tests/kvm/kvm_utils.py
>>> @@ -733,7 +733,7 @@ def remote_login(client, host, port, username,
>> password, prompt, linesep="\n",
>>>      elif client == "telnet":
>>>          cmd = "telnet -l %s %s %s" % (username, host, port)
>>>      elif client == "nc":
>>> -        cmd = "nc %s %s" % (host, port)
>>> +        cmd = "nc %s %s -w %s" % (host, port, timeout)
>>>      else:
>>>          logging.error("Unknown remote shell client: %s" % client)
>>>          return
>>
>> I don't understand how remote_login() can stall here.
>> kvm_utils._remote_login() doesn't rely on nc's self-termination.  If
>> no
>> shell prompt is available after 10 seconds, nc is forcefully
>> terminated
>> and _remote_login() fails.  If it somehow stalls this might indicate
>> a
>> bug somewhere.
> It is really rarely reproduce. Only meet this issue when guest panic or core dump.
> nc stall. Do not know why it is not terminated after 10s.
> 
> I think -w parameter is helpful in this situation.
> If it does not cause other issue,  we'd better add -w in nc command.
> 
> Thanks for your command. What do you think?
> 
> Feng Yang

Adding -w 10 may cause trouble.  If a good functional session is idle
for more than 10 seconds during a test, it will be closed.  For example,
if you run a command that takes more than 10 seconds to complete, and
produces no output while it runs, the session will be closed.

Also, I doubt it'll solve the problem you've experienced.  As it is, the
code should (and usually does) properly handle the case of nc not
terminating.

If you manage to reproduce this again please save the log so I can have
a look at it.

Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Feng Yang]

----- "Michael Goldish" <mgoldish@redhat.com> wrote:

> From: "Michael Goldish" <mgoldish@redhat.com>
> To: "Feng Yang" <fyang@redhat.com>
> Cc: autotest@test.kernel.org, kvm@vger.kernel.org
> Sent: Wednesday, October 20, 2010 6:48:42 PM GMT +08:00 Beijing / Chongqing / Hong Kong / Urumqi
> Subject: Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py
>
> On 10/20/2010 12:18 PM, Feng Yang wrote:
> > 
> > ----- "Michael Goldish" <mgoldish@redhat.com> wrote:
> > 
> >> From: "Michael Goldish" <mgoldish@redhat.com>
> >> To: "Feng Yang" <fyang@redhat.com>
> >> Cc: autotest@test.kernel.org, kvm@vger.kernel.org
> >> Sent: Wednesday, October 20, 2010 5:11:32 PM GMT +08:00 Beijing /
> Chongqing / Hong Kong / Urumqi
> >> Subject: Re: [PATCH] KVM Test: add -w parameter in nc command in
> kvm_utils.py
> >>
> >> On 10/20/2010 08:55 AM, Feng Yang wrote:
> >>> If a connection and stdin are idle for more than timeout seconds,
> >>> then the connection is silently closed. withou this paramter,
> >>> nc will listen forever for a connection. This may cause our test
> >>> hang. redmine issue:
> >>> http://redmine.englab.nay.redhat.com/issues/show/6947
> >>> Add -w parameter should fix this issue.
> >>>
> >>> Signed-off-by: Feng Yang <fyang@redhat.com>
> >>> ---
> >>>  client/tests/kvm/kvm_utils.py |    2 +-
> >>>  1 files changed, 1 insertions(+), 1 deletions(-)
> >>>
> >>> diff --git a/client/tests/kvm/kvm_utils.py
> >> b/client/tests/kvm/kvm_utils.py
> >>> index a51c857..526d38d 100644
> >>> --- a/client/tests/kvm/kvm_utils.py
> >>> +++ b/client/tests/kvm/kvm_utils.py
> >>> @@ -733,7 +733,7 @@ def remote_login(client, host, port,
> username,
> >> password, prompt, linesep="\n",
> >>>      elif client == "telnet":
> >>>          cmd = "telnet -l %s %s %s" % (username, host, port)
> >>>      elif client == "nc":
> >>> -        cmd = "nc %s %s" % (host, port)
> >>> +        cmd = "nc %s %s -w %s" % (host, port, timeout)
> >>>      else:
> >>>          logging.error("Unknown remote shell client: %s" %
> client)
> >>>          return
> >>
> >> I don't understand how remote_login() can stall here.
> >> kvm_utils._remote_login() doesn't rely on nc's self-termination. 
> If
> >> no
> >> shell prompt is available after 10 seconds, nc is forcefully
> >> terminated
> >> and _remote_login() fails.  If it somehow stalls this might
> indicate
> >> a
> >> bug somewhere.
> > It is really rarely reproduce. Only meet this issue when guest panic
> or core dump.
> > nc stall. Do not know why it is not terminated after 10s.
> > 
> > I think -w parameter is helpful in this situation.
> > If it does not cause other issue,  we'd better add -w in nc
> command.
> > 
> > Thanks for your command. What do you think?
> > 
> > Feng Yang
> 
> Adding -w 10 may cause trouble.  If a good functional session is idle
> for more than 10 seconds during a test, it will be closed.  For
> example,
> if you run a command that takes more than 10 seconds to complete, and
> produces no output while it runs, the session will be closed.
Seems the session also will be closed in our current code in this situation.
If no output for 10s, _remote_login() will return False. Then session will be closed in remote_login().

I have run some cases, it works well.  But I think we'd better first post this code, in case it really cause trouble.

I will do more test on it.

> 
> Also, I doubt it'll solve the problem you've experienced.  As it is,
> the
> code should (and usually does) properly handle the case of nc not
> terminating.
> 
> If you manage to reproduce this again please save the log so I can
> have
> a look at it.

When meet this issue again, I will send log to you. Thanks for your help!

Feng Yang



> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Michael Goldish]

On 10/21/2010 03:57 AM, Feng Yang wrote:
> 
> ----- "Michael Goldish" <mgoldish@redhat.com> wrote:
> 
>> From: "Michael Goldish" <mgoldish@redhat.com>
>> To: "Feng Yang" <fyang@redhat.com>
>> Cc: autotest@test.kernel.org, kvm@vger.kernel.org
>> Sent: Wednesday, October 20, 2010 6:48:42 PM GMT +08:00 Beijing / Chongqing / Hong Kong / Urumqi
>> Subject: Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py
>>
>> On 10/20/2010 12:18 PM, Feng Yang wrote:
>>>
>>> ----- "Michael Goldish" <mgoldish@redhat.com> wrote:
>>>
>>>> From: "Michael Goldish" <mgoldish@redhat.com>
>>>> To: "Feng Yang" <fyang@redhat.com>
>>>> Cc: autotest@test.kernel.org, kvm@vger.kernel.org
>>>> Sent: Wednesday, October 20, 2010 5:11:32 PM GMT +08:00 Beijing /
>> Chongqing / Hong Kong / Urumqi
>>>> Subject: Re: [PATCH] KVM Test: add -w parameter in nc command in
>> kvm_utils.py
>>>>
>>>> On 10/20/2010 08:55 AM, Feng Yang wrote:
>>>>> If a connection and stdin are idle for more than timeout seconds,
>>>>> then the connection is silently closed. withou this paramter,
>>>>> nc will listen forever for a connection. This may cause our test
>>>>> hang. redmine issue:
>>>>> http://redmine.englab.nay.redhat.com/issues/show/6947
>>>>> Add -w parameter should fix this issue.
>>>>>
>>>>> Signed-off-by: Feng Yang <fyang@redhat.com>
>>>>> ---
>>>>>  client/tests/kvm/kvm_utils.py |    2 +-
>>>>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>>>>
>>>>> diff --git a/client/tests/kvm/kvm_utils.py
>>>> b/client/tests/kvm/kvm_utils.py
>>>>> index a51c857..526d38d 100644
>>>>> --- a/client/tests/kvm/kvm_utils.py
>>>>> +++ b/client/tests/kvm/kvm_utils.py
>>>>> @@ -733,7 +733,7 @@ def remote_login(client, host, port,
>> username,
>>>> password, prompt, linesep="\n",
>>>>>      elif client == "telnet":
>>>>>          cmd = "telnet -l %s %s %s" % (username, host, port)
>>>>>      elif client == "nc":
>>>>> -        cmd = "nc %s %s" % (host, port)
>>>>> +        cmd = "nc %s %s -w %s" % (host, port, timeout)
>>>>>      else:
>>>>>          logging.error("Unknown remote shell client: %s" %
>> client)
>>>>>          return
>>>>
>>>> I don't understand how remote_login() can stall here.
>>>> kvm_utils._remote_login() doesn't rely on nc's self-termination. 
>> If
>>>> no
>>>> shell prompt is available after 10 seconds, nc is forcefully
>>>> terminated
>>>> and _remote_login() fails.  If it somehow stalls this might
>> indicate
>>>> a
>>>> bug somewhere.
>>> It is really rarely reproduce. Only meet this issue when guest panic
>> or core dump.
>>> nc stall. Do not know why it is not terminated after 10s.
>>>
>>> I think -w parameter is helpful in this situation.
>>> If it does not cause other issue,  we'd better add -w in nc
>> command.
>>>
>>> Thanks for your command. What do you think?
>>>
>>> Feng Yang
>>
>> Adding -w 10 may cause trouble.  If a good functional session is idle
>> for more than 10 seconds during a test, it will be closed.  For
>> example,
>> if you run a command that takes more than 10 seconds to complete, and
>> produces no output while it runs, the session will be closed.
> Seems the session also will be closed in our current code in this situation.
> If no output for 10s, _remote_login() will return False. Then session will be closed in remote_login().

If the login process takes more than 10s, yes, the session will be
closed.  However, if we use -w 10, the session will be closed whenever
it becomes idle, not just during login.  So if we login successfully and
then run a test (e.g. an autoit script), after 10s of no output the test
will be terminated.

> I have run some cases, it works well.  But I think we'd better first post this code, in case it really cause trouble.
> 
> I will do more test on it.
> 
>>
>> Also, I doubt it'll solve the problem you've experienced.  As it is,
>> the
>> code should (and usually does) properly handle the case of nc not
>> terminating.
>>
>> If you manage to reproduce this again please save the log so I can
>> have
>> a look at it.
> 
> When meet this issue again, I will send log to you. Thanks for your help!
> 
> Feng Yang
> 
> 
> 
>> --
>> To unsubscribe from this list: send the line "unsubscribe kvm" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
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Re: [PATCH] KVM Test: add -w parameter in nc command in kvm_utils.py

[Lucas Meneghel Rodrigues]

On Wed, 2010-10-20 at 14:55 +0800, Feng Yang wrote:
> If a connection and stdin are idle for more than timeout seconds,
> then the connection is silently closed. withou this paramter,
> nc will listen forever for a connection. This may cause our test
> hang. redmine issue:
> http://redmine.englab.nay.redhat.com/issues/show/6947
> Add -w parameter should fix this issue.

Feng, for reasons already explained by Michael, I'll drop this patch
from the queue and not apply it, OK?

Thanks!

> Signed-off-by: Feng Yang <fyang@redhat.com>
> ---
>  client/tests/kvm/kvm_utils.py |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/client/tests/kvm/kvm_utils.py b/client/tests/kvm/kvm_utils.py
> index a51c857..526d38d 100644
> --- a/client/tests/kvm/kvm_utils.py
> +++ b/client/tests/kvm/kvm_utils.py
> @@ -733,7 +733,7 @@ def remote_login(client, host, port, username, password, prompt, linesep="\n",
>      elif client == "telnet":
>          cmd = "telnet -l %s %s %s" % (username, host, port)
>      elif client == "nc":
> -        cmd = "nc %s %s" % (host, port)
> +        cmd = "nc %s %s -w %s" % (host, port, timeout)
>      else:
>          logging.error("Unknown remote shell client: %s" % client)
>          return