Great, thanks Lukasz!
Matevz
On 8/26/13 2:55 PM, Lukasz Janyst wrote:
> I am actually also away. It looks like something in XrdPosix is forcing new
> connections. I will have a closer look once I am back on Wednesday.
>
> Lukasz
>
> On 8/26/13 11:46 PM, Lukasz Janyst wrote:
>> I call it a trick because the only context I have seen it used in is forcing
>> new physical connections instead of reusing existing ones.
>>
>> Lukasz
>>
>> On 8/26/13 11:45 PM, Lukasz Janyst wrote:
>>> Hi Matevz,
>>>
>>> Andy's on vacation until 2nd Sep.
>>>
>>> Lukasz
>>>
>>> On 8/26/13 11:28 PM, Matevz Tadel wrote:
>>>> Hi Lukasz, Everybody,
>>>>
>>>> On 8/24/13 5:55 AM, Lukasz Janyst wrote:
>>>>> Yes, in fact the username "trick" to trigger the new connections would still
>>>>> work with the new client and that's likely what is happening here.
>>>>
>>>> Hmmh ... why do you call it a trick? And where are the usernames coming
>>>> from? This is all running within a single xrootd-proxy process ... so it is
>>>> always the same user, I don't see how this could change in any way. (On
>>>> server side and in monitoring, this is obviously a different user, as port
>>>> number is also combined into it.)
>>>>
>>>> Anyway ... this seems a really bad idea for the proxy :)
>>>>
>>>> Here is a dump of server/monitoring-side usernames for a bunch of
>>>> consecutive file-close events. You can see some of them get reused ... but
>>>> 105 of such connections stayed for 3 days+ (after reading ~300 files with
>>>> 300 XrdCls in a single process).
>>>>
>>>> * 413974 * alja.2636:[log in to unmask] *
>>>> * 415017 * alja.2636:[log in to unmask] *
>>>> * 416011 * alja.2636:[log in to unmask] *
>>>> * 416476 * alja.2636:[log in to unmask] *
>>>> * 417680 * alja.2636:[log in to unmask] *
>>>> * 419305 * alja.2636:[log in to unmask] *
>>>> * 419376 * alja.2636:[log in to unmask] *
>>>> * 419520 * alja.2636:[log in to unmask] *
>>>> * 419599 * alja.2636:[log in to unmask] *
>>>> * 419942 * alja.2636:[log in to unmask] *
>>>> * 420628 * alja.2636:[log in to unmask] *
>>>> * 421065 * alja.2636:[log in to unmask] *
>>>> * 422202 * alja.2636:[log in to unmask] *
>>>> * 422688 * alja.2636:[log in to unmask] *
>>>> * 423059 * alja.2636:[log in to unmask] *
>>>> * 423080 * alja.2636:[log in to unmask] *
>>>> * 424121 * alja.2636:[log in to unmask] *
>>>> * 424264 * alja.2636:[log in to unmask] *
>>>> * 431576 * alja.2636:[log in to unmask] *
>>>> * 488603 * alja.2636:[log in to unmask] *
>>>> * 489027 * alja.2636:[log in to unmask] *
>>>> * 489340 * alja.2636:[log in to unmask] *
>>>> * 494316 * alja.2636:[log in to unmask] *
>>>> * 494699 * alja.2636:[log in to unmask] *
>>>> * 496100 * alja.2636:[log in to unmask] *
>>>>
>>>>> In fact you can see what is exactly happening if you set the XRD_LOGLEVEL and
>>>>> XRD_LOGFILE envvars as described in the xrdcopy man page.
>>>>
>>>> Alja will run our test with this on ... but whatever the outcome, these
>>>> connections should still be closed at some point.
>>>>
>>>> Andy, can you please comment on this? [Does anybody know, is Andy away ...
>>>> or I should kick his chair in a separate email?]
>>>>
>>>> Cheers,
>>>> Matevz
>>>>
>>>>> Cheers,
>>>>> Lukasz
>>>>>
>>>>> On 23.08.2013 21:58, Fabrizio Furano wrote:
>>>>>> Hi guys,
>>>>>>
>>>>>> you are reminding to me a historical thing with this thread. You may
>>>>>> want to doublecheck these two points, and see if the defaults or the
>>>>>> behavior is appropriate to the behavior of your proxy:
>>>>>>
>>>>>> - by choice the connections to the redirectors had a very long TTL,
>>>>>> one day if I remember correctly
>>>>>> - at some point, due to some interaction with the sec (don't remember
>>>>>> exactly what by now) the behavior was changed to having one physical
>>>>>> connection per process per user. Maybe Gerri remembers the rationale of
>>>>>> this better than me. My point is to raise that if one sees many phyconns
>>>>>> from the same process, they could be linked to different user ids. Worth
>>>>>> checking IMHO.
>>>>>>
>>>>>> Hope that helps.
>>>>>>
>>>>>> Cheers
>>>>>> Fabrizio
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 8/23/13 9:42 PM, Brian Bockelman wrote:
>>>>>>> On Aug 23, 2013, at 2:05 PM, Alja Mrak Tadel <[log in to unmask]> wrote:
>>>>>>>
>>>>>>>>>> normally XrdCl would open one connection per server it contacts.
>>>>>>>>>> Not per file.
>>>>>>>>>
>>>>>>>>> OK, how do we get 105 connections from a single process to the
>>>>>>>>> meta-manager then? :)
>>>>>>>>
>>>>>>>>
>>>>>>>> FYI:: The connections listed with netstat are to the origin
>>>>>>>> xrootd.unl.edu.
>>>>>>>>
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> So - we see duplicate connections to the redirector, but no duplicate
>>>>>>> connections to the data server?
>>>>>>>
>>>>>>> Could be a client bug, of course!
>>>>>>>
>>>>>>> Brian
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>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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