[syslog-ng] [Non-DoD Source] Re: Syslog 3.5 (pipe file issue)

Sun Oct 29 12:40:33 UTC 2017

No, the inode of the named pipe is not changed after creation. The data
itself going through the pipe does not hit the disk, it's completely an
in-memory transport.

-- 
Bazsi

On Fri, Oct 27, 2017 at 7:55 PM, Amin, Jitesh CTR (US) <
jitesh.amin.ctr at mail.mil> wrote:

> Hi Laszlo,
> Though wouldn't the date/timestamp on the file be updated as the data is
> flowing through the pipe.
>
> Thanks
> Jitesh
> ------------------------------
> *From:* syslog-ng [syslog-ng-bounces at lists.balabit.hu] on behalf of
> László Várady [laszlo.varady at balabit.com]
> *Sent:* Friday, October 27, 2017 11:27 AM
> *To:* Syslog-ng users' and developers' mailing list
> *Subject:* Re: [syslog-ng] [Non-DoD Source] Re: Syslog 3.5 (pipe file
> issue)
>
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> ------------------------------
>
>
> Hi,
>
> As Laci pointed out, this is an expected behavior.
> Named pipes are not regular files, the "file size" is always 0 byte.
>
> From Caution-https://linux.die.net/man/4/fifo < Caution-h
> ttps://linux.die.net/man/4/fifo > :
> *When processes are exchanging data via the FIFO, the kernel passes all
> data internally without writing it to the file system.*
>
> If you are interested in the capacity of named pipes, you can read about
> this here:
> Caution-https://linux.die.net/man/7/pipe < Caution-https://
> linux.die.net/man/7/pipe >  (Chapter name: Pipe capacity)
>
> --
> László Várady
>
> On Fri, Oct 27, 2017 at 4:56 PM Amin, Jitesh CTR (US) <
> jitesh.amin.ctr at mail.mil < Caution-mailto:jitesh.amin.ctr at mail.mil > >
> wrote:
>
>> Hi Laci,
>> So we can create named pipe object with filename successfully.
>>
>> But the then the file always shows 0 bytes in size even after data is
>> being written to this file. Additionally the timestamp on this file never
>> changes (as new data get's written and so I would assume that modify date
>> on file would also be updated).
>>
>> Thanks
>> Jitesh
>> ------------------------------
>> *From:* syslog-ng [syslog-ng-bounces at lists.balabit.hu < Caution-mailto:sy
>> slog-ng-bounces at lists.balabit.hu > ] on behalf of Szemere, László [
>> laszlo.szemere at balabit.com < Caution-mailto:laszlo.szemere at balabit.com
>>  > ]
>> *Sent:* Friday, October 27, 2017 9:46 AM
>> *To:* Syslog-ng users' and developers' mailing list
>> *Subject:* [Non-DoD Source] Re: [syslog-ng] Syslog 3.5 (pipe file issue)
>>
>> All active links contained in this email were disabled. Please verify the
>> identity of the sender, and confirm the authenticity of all links contained
>> within the message prior to copying and pasting the address to a Web
>> browser.
>>
>> ------------------------------
>>
>>
>> Hello Jitesh,
>>
>>  I am afraid I can not clearly understand your problem. Since OSE 3.0.2,
>> a named pipe destination creates a new pipe object automatically with the
>> predefined filename. (Caution-Caution-https://www.
>> balabit.com/documents/syslog-ng-ose-3.11-guides/en/syslog-
>> ng-ose-guide-admin/html-single/index.html#configuring-destinations-pipe
>>  < Caution-https://www.balabit.com/documents/syslog-ng-ose-3.11-
>> guides/en/syslog-ng-ose-guide-admin/html-single/index.html#
>> configuring-destinations-pipe >  < Caution-Caution-https://
>> www.balabit.com/documents/syslog-ng-ose-3.11-guides/en/
>> syslog-ng-ose-guide-admin/html-single/index.html#
>> configuring-destinations-pipe < Caution-https://www.balabit.
>> com/documents/syslog-ng-ose-3.11-guides/en/syslog-ng-ose-
>> guide-admin/html-single/index.html#configuring-destinations-pipe >  > )
>>
>>  For me, this is the expected behavior of named pipes (man
>> page: Caution-Caution-http://man7.org/linux/man-pages/man1/mkfifo.1.html
>>  < Caution-http://man7.org/linux/man-pages/man1/mkfifo.1.html >  <
>> Caution-Caution-http://man7.org/linux/man-pages/man1/mkfifo.1.html
>>  < Caution-http://man7.org/linux/man-pages/man1/mkfifo.1.html >  >
>> further information on level 3: Caution-Caution-http://man7.
>> org/linux/man-pages/man3/mkfifo.3.html < Caution-http:/
>> /man7.org/linux/man-pages/man3/mkfifo.3.html >  < Caution-Caution-
>> http://man7.org/linux/man-pages/man3/mkfifo.3.html < Caution-http:/
>> /man7.org/linux/man-pages/man3/mkfifo.3.html >  > ). Please try to
>> rephrase your question, to give us more understanding about your use case.
>>
>> Br,
>> Laci
>>
>>
>>
>>
>> On Fri, Oct 27, 2017 at 2:42 PM, Amin, Jitesh CTR (US) <
>> jitesh.amin.ctr at mail.mil < Caution-mailto:jitesh.amin.ctr at mail.mil
>>  >  < Caution-Caution-mailto:jitesh.amin.ctr at mail.mil < Caution-mailto:
>> jitesh.amin.ctr at mail.mil >  > > wrote:
>>
>>> Hi,
>>> We have the syslog-ng 3.5 installed on Linux OS. We are trying to use
>>> the pipe function (to pipe data to the log file). This pipe file is FIFO.
>>>
>>> One of the issues we are seeing is that, the file size of this pipe file
>>> is always ZERO and never grows and second the timestampe on the file never
>>> updates or changes.
>>>
>>> Though when we do a "cat pipefilename" command we do see contents of the
>>> file.
>>>
>>> Can you please let us know what we could be doing wrong or any feedback
>>> on how to resolve the issue?
>>>
>>> Thanks
>>> Jitesh
>>>
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