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Posted to users@qpid.apache.org by Terance Dias <te...@socialtwist.com> on 2012/10/04 14:29:04 UTC
qpid async replication and failover
Hi,
We are trying out qpid with async replication. We have multiple clients
accessing the master node for reading and writing messages. If the master
node goes down, the client that tried to access it failsover to the slave
node.
The problem that we are facing is that if the master recovers and one of
the other clients that had not tried to access the master node (while it as
down) would not have failed over to the slave and will continue to access
the master. So I could end up having some of my clients accessing the
master while some are accessing the slave. This could lead to inconsistent
state of the queues.
My question is how do i get all my clients to failover all at once. I
realize that perhaps this is not a problem that qpid should solve and maybe
should be solved outside of qpid but I just want to know if anybody has
faced similar problem before. I guess setting up circular replication (so
that both nodes are in sync) could help but qpid doesn't support circular
replication. Any thoughts?
Thanks,
Terance.
Re: qpid async replication and failover
Posted by Terance Dias <te...@socialtwist.com>.
Does that mean that the only difference between the new async-replication
module and active-passive cluster is that the async-replication will accept
connections to both (primary and backup) brokers while active-passive
cluster will accept connections only to primary broker? Both will depend on
CMAN for recovery. Is that correct?
Thanks,
Terance.
On Mon, Oct 22, 2012 at 11:30 PM, Alan Conway <ac...@redhat.com> wrote:
> On Mon, 2012-10-22 at 11:15 +0530, Terance Dias wrote:
> > Thanks a lot for your reply Alan.
> >
> > I just had a few questions about the new async-replication module.
> > 1. With the new async-replication module, will the backup broker reject
> > connections like in the active-passive cluster?
>
> No, if you set up replication with qpid-ha both brokers remainfully
> functional
>
> > 2. Is there a manual step involved in promoting the backup broker to
> > primary when the primary broker becomes unreachable?
>
> When CMAN detects that the primary is down it calls the
> script /etc/init.d/qpidd-primary with the argument "start" on the host
> of the new primary. You could add other start-up work to this script.
> This is a temporary workaround till we get things fully automated.
>
> >
> > Thanks,
> > Terance.
> >
> > On Fri, Oct 19, 2012 at 7:14 PM, Alan Conway <ac...@redhat.com> wrote:
> >
> > > On Fri, 2012-10-19 at 11:09 +0530, Terance Dias wrote:
> > > > I tried the active-passive cluster but it turns out that for this
> cluster
> > > > to work all the nodes are required to be in the same network (since
> it
> > > > depends on cman service which only works (efficiently) for nodes in
> the
> > > > same subnet). This doesn't work for us since we need the backup node
> to
> > > be
> > > > present in another network. Is there some other way we can achieve
> this
> > > and
> > > > solve the fail-over problem mentioned earlier in this thread.
> > >
> > > You can use the async-replication module to replicate to an off-site
> > > node but it is soon (0.20) to be replaced by an improved scheme using
> > > the same replication code as the active-passive cluster.
> > >
> > > You can experiment with the new scheme now, using
> > > qpid-ha replicate <queue> <from-node>
> > >
> > > The thing that's missing is that if the receiving end is a cluster, and
> > > the primary fails, the replication link will not automatically be
> > > re-established on the new primary. One way to work around this is to
> > > write a custom qpid-primary script that re-establishes links when a
> > > broker is promoted to primary.
> > >
> > >
> > >
> > > >
> > > > Thanks,
> > > > Terance.
> > > >
> > > > On Fri, Oct 5, 2012 at 3:33 PM, Gordon Sim <gs...@redhat.com> wrote:
> > > >
> > > > > On 10/05/2012 10:40 AM, Terance Dias wrote:
> > > > >
> > > > >> Thanks a lot for your reply Gordon.
> > > > >>
> > > > >> We are using the replication described at
> > > http://qpid.apache.org/books/*
> > > > >> *** <http://qpid.apache.org/books/**>
> > > > >> trunk/AMQP-Messaging-Broker-****CPP-Book/html/queue-state-****
> > > > >> replication.html<http://qpid.**apache.org/books/trunk/AMQP-**
> > > > >> Messaging-Broker-CPP-Book/**html/queue-state-replication.**html<
> > >
> http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html
> > > >
> > > > >> >
> > > > >>
> > > > >> .
> > > > >> We are running on Ubuntu.
> > > > >>
> > > > >
> > > > > Ok, that certainly seems to have rgmanager:
> > > http://manpages.ubuntu.com/**
> > > > > manpages/precise/man8/**rgmanager.8.html<
> > > http://manpages.ubuntu.com/manpages/precise/man8/rgmanager.8.html>
> > > > >
> > > > >
> > > > >> We decided to go with this kind of replication because it allowed
> HA
> > > > >> solution across networks. Does the new mechanism work across
> networks
> > > or
> > > > >> are the nodes required to be in the same network?
> > > > >>
> > > > >
> > > > > No. The replication in the new HA scheme is done over AMQP (over
> > > > > inter-broker aka 'federation' links).
> > > > >
> > > > >
> > > > > Also, I'm new to Linux. So I just wanted to know how rgmanager
> works.
> > > Does
> > > > >> it run on a separate node and monitors the cluster nodes? In that
> > > case can
> > > > >> it be a single point of failure?
> > > > >>
> > > > >
> > > > > No, I believe it runs on all the nodes participating in the
> cluster.
> > > These
> > > > > daemons all communicate such that they can determine when one node
> is
> > > > > 'down', shut it out the system and attempt to recover it.
> > > > >
> > > > >
> > > > > Also, Please let me know if you know if anybody has deployed the
> new
> > > > >> cluster mechanism in production.
> > > > >>
> > > > >
> > > > > No, I don;t think so yet. Though it is undergoing testing right
> now by
> > > an
> > > > > actual project.
> > > > >
> > > > >
> > > > >
> > > > >
> > >
> ------------------------------**------------------------------**---------
> > > > > To unsubscribe, e-mail: users-unsubscribe@qpid.apache.**org<
> > > users-unsubscribe@qpid.apache.org>
> > > > > For additional commands, e-mail: users-help@qpid.apache.org
> > > > >
> > > > >
> > >
> > >
> > >
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: users-unsubscribe@qpid.apache.org
> > > For additional commands, e-mail: users-help@qpid.apache.org
> > >
> > >
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@qpid.apache.org
> For additional commands, e-mail: users-help@qpid.apache.org
>
>
Re: qpid async replication and failover
Posted by Alan Conway <ac...@redhat.com>.
On Mon, 2012-10-22 at 11:15 +0530, Terance Dias wrote:
> Thanks a lot for your reply Alan.
>
> I just had a few questions about the new async-replication module.
> 1. With the new async-replication module, will the backup broker reject
> connections like in the active-passive cluster?
No, if you set up replication with qpid-ha both brokers remainfully
functional
> 2. Is there a manual step involved in promoting the backup broker to
> primary when the primary broker becomes unreachable?
When CMAN detects that the primary is down it calls the
script /etc/init.d/qpidd-primary with the argument "start" on the host
of the new primary. You could add other start-up work to this script.
This is a temporary workaround till we get things fully automated.
>
> Thanks,
> Terance.
>
> On Fri, Oct 19, 2012 at 7:14 PM, Alan Conway <ac...@redhat.com> wrote:
>
> > On Fri, 2012-10-19 at 11:09 +0530, Terance Dias wrote:
> > > I tried the active-passive cluster but it turns out that for this cluster
> > > to work all the nodes are required to be in the same network (since it
> > > depends on cman service which only works (efficiently) for nodes in the
> > > same subnet). This doesn't work for us since we need the backup node to
> > be
> > > present in another network. Is there some other way we can achieve this
> > and
> > > solve the fail-over problem mentioned earlier in this thread.
> >
> > You can use the async-replication module to replicate to an off-site
> > node but it is soon (0.20) to be replaced by an improved scheme using
> > the same replication code as the active-passive cluster.
> >
> > You can experiment with the new scheme now, using
> > qpid-ha replicate <queue> <from-node>
> >
> > The thing that's missing is that if the receiving end is a cluster, and
> > the primary fails, the replication link will not automatically be
> > re-established on the new primary. One way to work around this is to
> > write a custom qpid-primary script that re-establishes links when a
> > broker is promoted to primary.
> >
> >
> >
> > >
> > > Thanks,
> > > Terance.
> > >
> > > On Fri, Oct 5, 2012 at 3:33 PM, Gordon Sim <gs...@redhat.com> wrote:
> > >
> > > > On 10/05/2012 10:40 AM, Terance Dias wrote:
> > > >
> > > >> Thanks a lot for your reply Gordon.
> > > >>
> > > >> We are using the replication described at
> > http://qpid.apache.org/books/*
> > > >> *** <http://qpid.apache.org/books/**>
> > > >> trunk/AMQP-Messaging-Broker-****CPP-Book/html/queue-state-****
> > > >> replication.html<http://qpid.**apache.org/books/trunk/AMQP-**
> > > >> Messaging-Broker-CPP-Book/**html/queue-state-replication.**html<
> > http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html
> > >
> > > >> >
> > > >>
> > > >> .
> > > >> We are running on Ubuntu.
> > > >>
> > > >
> > > > Ok, that certainly seems to have rgmanager:
> > http://manpages.ubuntu.com/**
> > > > manpages/precise/man8/**rgmanager.8.html<
> > http://manpages.ubuntu.com/manpages/precise/man8/rgmanager.8.html>
> > > >
> > > >
> > > >> We decided to go with this kind of replication because it allowed HA
> > > >> solution across networks. Does the new mechanism work across networks
> > or
> > > >> are the nodes required to be in the same network?
> > > >>
> > > >
> > > > No. The replication in the new HA scheme is done over AMQP (over
> > > > inter-broker aka 'federation' links).
> > > >
> > > >
> > > > Also, I'm new to Linux. So I just wanted to know how rgmanager works.
> > Does
> > > >> it run on a separate node and monitors the cluster nodes? In that
> > case can
> > > >> it be a single point of failure?
> > > >>
> > > >
> > > > No, I believe it runs on all the nodes participating in the cluster.
> > These
> > > > daemons all communicate such that they can determine when one node is
> > > > 'down', shut it out the system and attempt to recover it.
> > > >
> > > >
> > > > Also, Please let me know if you know if anybody has deployed the new
> > > >> cluster mechanism in production.
> > > >>
> > > >
> > > > No, I don;t think so yet. Though it is undergoing testing right now by
> > an
> > > > actual project.
> > > >
> > > >
> > > >
> > > >
> > ------------------------------**------------------------------**---------
> > > > To unsubscribe, e-mail: users-unsubscribe@qpid.apache.**org<
> > users-unsubscribe@qpid.apache.org>
> > > > For additional commands, e-mail: users-help@qpid.apache.org
> > > >
> > > >
> >
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: users-unsubscribe@qpid.apache.org
> > For additional commands, e-mail: users-help@qpid.apache.org
> >
> >
---------------------------------------------------------------------
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Re: qpid async replication and failover
Posted by Terance Dias <te...@socialtwist.com>.
Thanks a lot for your reply Alan.
I just had a few questions about the new async-replication module.
1. With the new async-replication module, will the backup broker reject
connections like in the active-passive cluster?
2. Is there a manual step involved in promoting the backup broker to
primary when the primary broker becomes unreachable?
Thanks,
Terance.
On Fri, Oct 19, 2012 at 7:14 PM, Alan Conway <ac...@redhat.com> wrote:
> On Fri, 2012-10-19 at 11:09 +0530, Terance Dias wrote:
> > I tried the active-passive cluster but it turns out that for this cluster
> > to work all the nodes are required to be in the same network (since it
> > depends on cman service which only works (efficiently) for nodes in the
> > same subnet). This doesn't work for us since we need the backup node to
> be
> > present in another network. Is there some other way we can achieve this
> and
> > solve the fail-over problem mentioned earlier in this thread.
>
> You can use the async-replication module to replicate to an off-site
> node but it is soon (0.20) to be replaced by an improved scheme using
> the same replication code as the active-passive cluster.
>
> You can experiment with the new scheme now, using
> qpid-ha replicate <queue> <from-node>
>
> The thing that's missing is that if the receiving end is a cluster, and
> the primary fails, the replication link will not automatically be
> re-established on the new primary. One way to work around this is to
> write a custom qpid-primary script that re-establishes links when a
> broker is promoted to primary.
>
>
>
> >
> > Thanks,
> > Terance.
> >
> > On Fri, Oct 5, 2012 at 3:33 PM, Gordon Sim <gs...@redhat.com> wrote:
> >
> > > On 10/05/2012 10:40 AM, Terance Dias wrote:
> > >
> > >> Thanks a lot for your reply Gordon.
> > >>
> > >> We are using the replication described at
> http://qpid.apache.org/books/*
> > >> *** <http://qpid.apache.org/books/**>
> > >> trunk/AMQP-Messaging-Broker-****CPP-Book/html/queue-state-****
> > >> replication.html<http://qpid.**apache.org/books/trunk/AMQP-**
> > >> Messaging-Broker-CPP-Book/**html/queue-state-replication.**html<
> http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html
> >
> > >> >
> > >>
> > >> .
> > >> We are running on Ubuntu.
> > >>
> > >
> > > Ok, that certainly seems to have rgmanager:
> http://manpages.ubuntu.com/**
> > > manpages/precise/man8/**rgmanager.8.html<
> http://manpages.ubuntu.com/manpages/precise/man8/rgmanager.8.html>
> > >
> > >
> > >> We decided to go with this kind of replication because it allowed HA
> > >> solution across networks. Does the new mechanism work across networks
> or
> > >> are the nodes required to be in the same network?
> > >>
> > >
> > > No. The replication in the new HA scheme is done over AMQP (over
> > > inter-broker aka 'federation' links).
> > >
> > >
> > > Also, I'm new to Linux. So I just wanted to know how rgmanager works.
> Does
> > >> it run on a separate node and monitors the cluster nodes? In that
> case can
> > >> it be a single point of failure?
> > >>
> > >
> > > No, I believe it runs on all the nodes participating in the cluster.
> These
> > > daemons all communicate such that they can determine when one node is
> > > 'down', shut it out the system and attempt to recover it.
> > >
> > >
> > > Also, Please let me know if you know if anybody has deployed the new
> > >> cluster mechanism in production.
> > >>
> > >
> > > No, I don;t think so yet. Though it is undergoing testing right now by
> an
> > > actual project.
> > >
> > >
> > >
> > >
> ------------------------------**------------------------------**---------
> > > To unsubscribe, e-mail: users-unsubscribe@qpid.apache.**org<
> users-unsubscribe@qpid.apache.org>
> > > For additional commands, e-mail: users-help@qpid.apache.org
> > >
> > >
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@qpid.apache.org
> For additional commands, e-mail: users-help@qpid.apache.org
>
>
Re: qpid async replication and failover
Posted by Alan Conway <ac...@redhat.com>.
On Fri, 2012-10-19 at 11:09 +0530, Terance Dias wrote:
> I tried the active-passive cluster but it turns out that for this cluster
> to work all the nodes are required to be in the same network (since it
> depends on cman service which only works (efficiently) for nodes in the
> same subnet). This doesn't work for us since we need the backup node to be
> present in another network. Is there some other way we can achieve this and
> solve the fail-over problem mentioned earlier in this thread.
You can use the async-replication module to replicate to an off-site
node but it is soon (0.20) to be replaced by an improved scheme using
the same replication code as the active-passive cluster.
You can experiment with the new scheme now, using
qpid-ha replicate <queue> <from-node>
The thing that's missing is that if the receiving end is a cluster, and
the primary fails, the replication link will not automatically be
re-established on the new primary. One way to work around this is to
write a custom qpid-primary script that re-establishes links when a
broker is promoted to primary.
>
> Thanks,
> Terance.
>
> On Fri, Oct 5, 2012 at 3:33 PM, Gordon Sim <gs...@redhat.com> wrote:
>
> > On 10/05/2012 10:40 AM, Terance Dias wrote:
> >
> >> Thanks a lot for your reply Gordon.
> >>
> >> We are using the replication described at http://qpid.apache.org/books/*
> >> *** <http://qpid.apache.org/books/**>
> >> trunk/AMQP-Messaging-Broker-****CPP-Book/html/queue-state-****
> >> replication.html<http://qpid.**apache.org/books/trunk/AMQP-**
> >> Messaging-Broker-CPP-Book/**html/queue-state-replication.**html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html>
> >> >
> >>
> >> .
> >> We are running on Ubuntu.
> >>
> >
> > Ok, that certainly seems to have rgmanager: http://manpages.ubuntu.com/**
> > manpages/precise/man8/**rgmanager.8.html<http://manpages.ubuntu.com/manpages/precise/man8/rgmanager.8.html>
> >
> >
> >> We decided to go with this kind of replication because it allowed HA
> >> solution across networks. Does the new mechanism work across networks or
> >> are the nodes required to be in the same network?
> >>
> >
> > No. The replication in the new HA scheme is done over AMQP (over
> > inter-broker aka 'federation' links).
> >
> >
> > Also, I'm new to Linux. So I just wanted to know how rgmanager works. Does
> >> it run on a separate node and monitors the cluster nodes? In that case can
> >> it be a single point of failure?
> >>
> >
> > No, I believe it runs on all the nodes participating in the cluster. These
> > daemons all communicate such that they can determine when one node is
> > 'down', shut it out the system and attempt to recover it.
> >
> >
> > Also, Please let me know if you know if anybody has deployed the new
> >> cluster mechanism in production.
> >>
> >
> > No, I don;t think so yet. Though it is undergoing testing right now by an
> > actual project.
> >
> >
> >
> > ------------------------------**------------------------------**---------
> > To unsubscribe, e-mail: users-unsubscribe@qpid.apache.**org<us...@qpid.apache.org>
> > For additional commands, e-mail: users-help@qpid.apache.org
> >
> >
---------------------------------------------------------------------
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For additional commands, e-mail: users-help@qpid.apache.org
Re: qpid async replication and failover
Posted by Terance Dias <te...@socialtwist.com>.
I tried the active-passive cluster but it turns out that for this cluster
to work all the nodes are required to be in the same network (since it
depends on cman service which only works (efficiently) for nodes in the
same subnet). This doesn't work for us since we need the backup node to be
present in another network. Is there some other way we can achieve this and
solve the fail-over problem mentioned earlier in this thread.
Thanks,
Terance.
On Fri, Oct 5, 2012 at 3:33 PM, Gordon Sim <gs...@redhat.com> wrote:
> On 10/05/2012 10:40 AM, Terance Dias wrote:
>
>> Thanks a lot for your reply Gordon.
>>
>> We are using the replication described at http://qpid.apache.org/books/*
>> *** <http://qpid.apache.org/books/**>
>> trunk/AMQP-Messaging-Broker-****CPP-Book/html/queue-state-****
>> replication.html<http://qpid.**apache.org/books/trunk/AMQP-**
>> Messaging-Broker-CPP-Book/**html/queue-state-replication.**html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html>
>> >
>>
>> .
>> We are running on Ubuntu.
>>
>
> Ok, that certainly seems to have rgmanager: http://manpages.ubuntu.com/**
> manpages/precise/man8/**rgmanager.8.html<http://manpages.ubuntu.com/manpages/precise/man8/rgmanager.8.html>
>
>
>> We decided to go with this kind of replication because it allowed HA
>> solution across networks. Does the new mechanism work across networks or
>> are the nodes required to be in the same network?
>>
>
> No. The replication in the new HA scheme is done over AMQP (over
> inter-broker aka 'federation' links).
>
>
> Also, I'm new to Linux. So I just wanted to know how rgmanager works. Does
>> it run on a separate node and monitors the cluster nodes? In that case can
>> it be a single point of failure?
>>
>
> No, I believe it runs on all the nodes participating in the cluster. These
> daemons all communicate such that they can determine when one node is
> 'down', shut it out the system and attempt to recover it.
>
>
> Also, Please let me know if you know if anybody has deployed the new
>> cluster mechanism in production.
>>
>
> No, I don;t think so yet. Though it is undergoing testing right now by an
> actual project.
>
>
>
> ------------------------------**------------------------------**---------
> To unsubscribe, e-mail: users-unsubscribe@qpid.apache.**org<us...@qpid.apache.org>
> For additional commands, e-mail: users-help@qpid.apache.org
>
>
Re: qpid async replication and failover
Posted by Gordon Sim <gs...@redhat.com>.
On 10/05/2012 10:40 AM, Terance Dias wrote:
> Thanks a lot for your reply Gordon.
>
> We are using the replication described at http://qpid.apache.org/books/**
> trunk/AMQP-Messaging-Broker-**CPP-Book/html/queue-state-**replication.html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html>
> .
> We are running on Ubuntu.
Ok, that certainly seems to have rgmanager:
http://manpages.ubuntu.com/manpages/precise/man8/rgmanager.8.html
>
> We decided to go with this kind of replication because it allowed HA
> solution across networks. Does the new mechanism work across networks or
> are the nodes required to be in the same network?
No. The replication in the new HA scheme is done over AMQP (over
inter-broker aka 'federation' links).
> Also, I'm new to Linux. So I just wanted to know how rgmanager works. Does
> it run on a separate node and monitors the cluster nodes? In that case can
> it be a single point of failure?
No, I believe it runs on all the nodes participating in the cluster.
These daemons all communicate such that they can determine when one node
is 'down', shut it out the system and attempt to recover it.
> Also, Please let me know if you know if anybody has deployed the new
> cluster mechanism in production.
No, I don;t think so yet. Though it is undergoing testing right now by
an actual project.
---------------------------------------------------------------------
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Re: qpid async replication and failover
Posted by Terance Dias <te...@socialtwist.com>.
Thanks a lot for your reply Gordon.
We are using the replication described at http://qpid.apache.org/books/**
trunk/AMQP-Messaging-Broker-**CPP-Book/html/queue-state-**replication.html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html>
.
We are running on Ubuntu.
We decided to go with this kind of replication because it allowed HA
solution across networks. Does the new mechanism work across networks or
are the nodes required to be in the same network?
Also, I'm new to Linux. So I just wanted to know how rgmanager works. Does
it run on a separate node and monitors the cluster nodes? In that case can
it be a single point of failure?
Also, Please let me know if you know if anybody has deployed the new
cluster mechanism in production.
Thanks,
Terance.
On Fri, Oct 5, 2012 at 12:34 PM, Gordon Sim <gs...@redhat.com> wrote:
> On 10/04/2012 01:29 PM, Terance Dias wrote:
>
>> We are trying out qpid with async replication. We have multiple clients
>> accessing the master node for reading and writing messages. If the master
>> node goes down, the client that tried to access it failsover to the slave
>> node.
>> The problem that we are facing is that if the master recovers and one of
>> the other clients that had not tried to access the master node (while it
>> as
>> down) would not have failed over to the slave and will continue to access
>> the master. So I could end up having some of my clients accessing the
>> master while some are accessing the slave. This could lead to inconsistent
>> state of the queues.
>> My question is how do i get all my clients to failover all at once. I
>> realize that perhaps this is not a problem that qpid should solve and
>> maybe
>> should be solved outside of qpid but I just want to know if anybody has
>> faced similar problem before. I guess setting up circular replication (so
>> that both nodes are in sync) could help but qpid doesn't support circular
>> replication. Any thoughts?
>>
>
> Is the async replication you are using as described here:
> http://qpid.apache.org/books/**trunk/AMQP-Messaging-Broker-**
> CPP-Book/html/queue-state-**replication.html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html>
> ?
>
> If so you may be interested in a newer and more powerful mechanism:
>
> http://qpid.apache.org/books/**trunk/AMQP-Messaging-Broker-**
> CPP-Book/html/ch01s14.html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/ch01s14.html>
>
> and
>
> http://qpid.apache.org/books/**trunk/AMQP-Messaging-Broker-**
> CPP-Book/html/chap-Messaging_**User_Guide-Active_Passive_**Cluster.html<http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/chap-Messaging_User_Guide-Active_Passive_Cluster.html>
>
> This new HA module is available in the 0.18 release and will replace both
> the active-active cluster and the async queue replication from release 0.20.
>
> It includes the ability to reject clients when not the master, replication
> can be stopped and started simply (a problem with the old approach) and
> acknowledgement to publishers is delayed until replicated (which is useful
> for client based replay).
>
> The actual management of brokers (promotion of master etc) is done using
> rgmanager or similar cluster management tool. At present there are scripts
> only for rgmanager, but it would not be difficult I don't think to use
> pacemaker or some other tool.
>
> What platform are you running on?
>
>
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>
Re: qpid async replication and failover
Posted by Gordon Sim <gs...@redhat.com>.
On 10/04/2012 01:29 PM, Terance Dias wrote:
> We are trying out qpid with async replication. We have multiple clients
> accessing the master node for reading and writing messages. If the master
> node goes down, the client that tried to access it failsover to the slave
> node.
> The problem that we are facing is that if the master recovers and one of
> the other clients that had not tried to access the master node (while it as
> down) would not have failed over to the slave and will continue to access
> the master. So I could end up having some of my clients accessing the
> master while some are accessing the slave. This could lead to inconsistent
> state of the queues.
> My question is how do i get all my clients to failover all at once. I
> realize that perhaps this is not a problem that qpid should solve and maybe
> should be solved outside of qpid but I just want to know if anybody has
> faced similar problem before. I guess setting up circular replication (so
> that both nodes are in sync) could help but qpid doesn't support circular
> replication. Any thoughts?
Is the async replication you are using as described here:
http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/queue-state-replication.html?
If so you may be interested in a newer and more powerful mechanism:
http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/ch01s14.html
and
http://qpid.apache.org/books/trunk/AMQP-Messaging-Broker-CPP-Book/html/chap-Messaging_User_Guide-Active_Passive_Cluster.html
This new HA module is available in the 0.18 release and will replace
both the active-active cluster and the async queue replication from
release 0.20.
It includes the ability to reject clients when not the master,
replication can be stopped and started simply (a problem with the old
approach) and acknowledgement to publishers is delayed until replicated
(which is useful for client based replay).
The actual management of brokers (promotion of master etc) is done using
rgmanager or similar cluster management tool. At present there are
scripts only for rgmanager, but it would not be difficult I don't think
to use pacemaker or some other tool.
What platform are you running on?
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