You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@qpid.apache.org by Pavel Moravec <pm...@redhat.com> on 2011/05/20 16:26:53 UTC
Connection options: reconnect
Hi,
I have two quite technical questions concerning connection option "reconnect" that defines if the client shall transparently reconnect when the connection is lost (quoting "Programming in Apache Qpid" manual).
First question: What the "if the connection is lost" _should_ technically mean? TCP connection is lost, i.e. operating system announces to userspace that the socket / TCP connection is closed? Or some / all AMQP session(s) is/are lost? Or something else?
Second question: If reconnect:true is set, should the client bind to the broker with the same client_pid? Or a new one?
(some background to the questions: it seems there is a scenario that ends up the client thinks it has to reconnect to the broker while the broker keeps the previous connection open - the reconnection attempt is then rejected as it contains client_pid of an established session)
Thanks in advance for your thoughts.
Kind regards,
Pavel
Re: Connection options: reconnect
Posted by Pavel Moravec <pm...@redhat.com>.
Hello all,
I am afraid the JIRA case would be hard to fully resolve. See my comment added to the case.
Kind regards,
Pavel
----- Original Message -----
From: "Ilyushonak Barys" <Ba...@troika.ru>
To: users@qpid.apache.org
Sent: Monday, May 23, 2011 10:49:51 AM
Subject: RE: Connection options: reconnect
Gordon,
Thank you for the answer.
I created
https://issues.apache.org/jira/browse/QPID-3264
on the case Pavel described.
-----Original Message-----
From: Gordon Sim [mailto:gsim@redhat.com]
Sent: Monday, May 23, 2011 12:47 PM
To: users@qpid.apache.org
Subject: Re: Connection options: reconnect
On 05/20/2011 03:26 PM, Pavel Moravec wrote:
> Hi, I have two quite technical questions concerning connection option
> "reconnect" that defines if the client shall transparently reconnect
> when the connection is lost (quoting "Programming in Apache Qpid"
> manual).
>
> First question: What the "if the connection is lost" _should_
> technically mean? TCP connection is lost, i.e. operating system
> announces to userspace that the socket / TCP connection is closed?
Yes.
> Or
> some / all AMQP session(s) is/are lost? Or something else?
>
> Second question: If reconnect:true is set, should the client bind to
> the broker with the same client_pid? Or a new one?
The same one if it is the same process (the pid is the process id).
>
> (some background to the questions: it seems there is a scenario that
> ends up the client thinks it has to reconnect to the broker while the
> broker keeps the previous connection open - the reconnection attempt
> is then rejected as it contains client_pid of an established
> session)
That's the session id, which in the c++ is by default a random UUID and is reused when re-establishing a session on reconnect.
---------------------------------------------------------------------
Apache Qpid - AMQP Messaging Implementation
Project: http://qpid.apache.org
Use/Interact: mailto:users-subscribe@qpid.apache.org
_______________________________________________________
The information contained in this message may be privileged and conf idential and protected from disclosure. If you are not the original intended recipient, you are hereby notified that any review, retransmission, dissemination, or other use of, or taking of any action in reliance upon, this information is prohibited. If you have received this communication in error, please notify the sender immediately by replying to this message and delete it from your computer. Thank you for your cooperation. Troika Dialog, Russia.
If you need assistance please contact our Contact Center (+7495) 258 0500 or go to www.troika.ru/eng/Contacts/system.wbp
---------------------------------------------------------------------
Apache Qpid - AMQP Messaging Implementation
Project: http://qpid.apache.org
Use/Interact: mailto:users-subscribe@qpid.apache.org
RE: Connection options: reconnect
Posted by Ilyushonak Barys <Ba...@troika.ru>.
Gordon,
Thank you for the answer.
I created
https://issues.apache.org/jira/browse/QPID-3264
on the case Pavel described.
-----Original Message-----
From: Gordon Sim [mailto:gsim@redhat.com]
Sent: Monday, May 23, 2011 12:47 PM
To: users@qpid.apache.org
Subject: Re: Connection options: reconnect
On 05/20/2011 03:26 PM, Pavel Moravec wrote:
> Hi, I have two quite technical questions concerning connection option
> "reconnect" that defines if the client shall transparently reconnect
> when the connection is lost (quoting "Programming in Apache Qpid"
> manual).
>
> First question: What the "if the connection is lost" _should_
> technically mean? TCP connection is lost, i.e. operating system
> announces to userspace that the socket / TCP connection is closed?
Yes.
> Or
> some / all AMQP session(s) is/are lost? Or something else?
>
> Second question: If reconnect:true is set, should the client bind to
> the broker with the same client_pid? Or a new one?
The same one if it is the same process (the pid is the process id).
>
> (some background to the questions: it seems there is a scenario that
> ends up the client thinks it has to reconnect to the broker while the
> broker keeps the previous connection open - the reconnection attempt
> is then rejected as it contains client_pid of an established
> session)
That's the session id, which in the c++ is by default a random UUID and is reused when re-establishing a session on reconnect.
---------------------------------------------------------------------
Apache Qpid - AMQP Messaging Implementation
Project: http://qpid.apache.org
Use/Interact: mailto:users-subscribe@qpid.apache.org
_______________________________________________________
The information contained in this message may be privileged and conf idential and protected from disclosure. If you are not the original intended recipient, you are hereby notified that any review, retransmission, dissemination, or other use of, or taking of any action in reliance upon, this information is prohibited. If you have received this communication in error, please notify the sender immediately by replying to this message and delete it from your computer. Thank you for your cooperation. Troika Dialog, Russia.
If you need assistance please contact our Contact Center (+7495) 258 0500 or go to www.troika.ru/eng/Contacts/system.wbp
Re: Connection options: reconnect
Posted by Gordon Sim <gs...@redhat.com>.
On 05/20/2011 03:26 PM, Pavel Moravec wrote:
> Hi, I have two quite technical questions concerning connection option
> "reconnect" that defines if the client shall transparently reconnect
> when the connection is lost (quoting "Programming in Apache Qpid"
> manual).
>
> First question: What the "if the connection is lost" _should_
> technically mean? TCP connection is lost, i.e. operating system
> announces to userspace that the socket / TCP connection is closed?
Yes.
> Or
> some / all AMQP session(s) is/are lost? Or something else?
>
> Second question: If reconnect:true is set, should the client bind to
> the broker with the same client_pid? Or a new one?
The same one if it is the same process (the pid is the process id).
>
> (some background to the questions: it seems there is a scenario that
> ends up the client thinks it has to reconnect to the broker while the
> broker keeps the previous connection open - the reconnection attempt
> is then rejected as it contains client_pid of an established
> session)
That's the session id, which in the c++ is by default a random UUID and
is reused when re-establishing a session on reconnect.
---------------------------------------------------------------------
Apache Qpid - AMQP Messaging Implementation
Project: http://qpid.apache.org
Use/Interact: mailto:users-subscribe@qpid.apache.org