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Posted to solr-user@lucene.apache.org by Tri Nguyen <tr...@yahoo.com> on 2010/12/19 09:20:30 UTC
master master, repeaters
Hi,
In the master-slave configuration, I'm trying to figure out how to configure the
system setup for master failover.
Does solr support master-master setup? From my readings, solr does not.
I've read about repeaters as well where the slave can act as a master. When the
main master goes down, do the other slaves switch to the repeater?
Barring better solutions, I'm thinking about putting 2 masters behind a load
balancer.
If this is not implemented already, perhaps solr can be updated to support a
list of masters for fault tolerance.
Tri
Re: master master, repeaters
Posted by Lance Norskog <go...@gmail.com>.
Ah, thanks for pointing that out.
Each indexer needs its own marker for "where is new data in this
stream"? This way, when either the primary or secondary starts, it can
restart indexing from where it left off. The most reliable way to do
this is to search the indexer Solr for its last update.
Another problem is that if the backup has a completely different index
than the primary, when the query servers switch to the backup they
have to download a whole new index.
On Mon, Dec 20, 2010 at 12:45 AM, Upayavira <uv...@odoko.co.uk> wrote:
> I've successfully made extensive use of load balancers in sharded,
> replicated slave setups - see [1].
>
> My question is how that might work with a master. You can have a load
> balancer, but you'd need to configure it into a 'fail over but please
> don't fail back' configuration. I'm not sure if that is possible on the
> load balancers we have used. Otherwise, if your master had a five minute
> blip, you could have some content going to your backup, then traffic
> returning to your master, leading to master/backup out of sync and
> content missing from your master index.
>
> It seems to me, unless I am missing something, that while a load
> balancer can be useful, it is only as a part of a larger scheme when it
> comes to master replication. Or am I missing something?
>
> Upayavira
>
> [1] http://www.slideshare.net/sourcesense/sharded-solr-setup-with-master
>
> On Sun, 19 Dec 2010 22:41 -0800, "Lance Norskog" <go...@gmail.com>
> wrote:
>> If you have a load balancer available, that is a much cleaner solution
>> than anything else. After the main indexer comes back, you have to get
>> the current index state to it to start again. But otherwise
>>
>> On Sun, Dec 19, 2010 at 10:39 AM, Upayavira <uv...@odoko.co.uk> wrote:
>> >
>> >
>> > On Sun, 19 Dec 2010 10:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
>> > wrote:
>> >> How do we tell the slaves to point to the new master without modifying
>> >> the config files? Can we do this while the slave is up, issuing a
>> >> command to it?
>> >
>> > I believe this can be done (details are in
>> > http://wiki.apache.org/solr/SolrReplication), but I've not actually done
>> > it.
>> >
>> > Upayavira
>> >
>> >> --- On Sun, 12/19/10, Upayavira <uv...@odoko.co.uk> wrote:
>> >>
>> >>
>> >> From: Upayavira <uv...@odoko.co.uk>
>> >> Subject: Re: master master, repeaters
>> >> To: solr-user@lucene.apache.org
>> >> Date: Sunday, December 19, 2010, 10:13 AM
>> >>
>> >>
>> >> We had a (short) thread on this late last week.
>> >>
>> >> Solr doesn't support automatic failover of the master, at least in
>> >> 1.4.1. I've been discussing with my colleague (Tommaso) about ways to
>> >> achieve this.
>> >>
>> >> There's ways we could 'fake it', scripting the following:
>> >>
>> >> * set up a 'backup' master, as a replica of the actual master
>> >> * monitor the master for 'up-ness'
>> >> * if it fails:
>> >> * tell the master to start indexing to the backup instead
>> >> * tell the slave(s) to connect to a different master (the backup)
>> >> * then, when the master is back:
>> >> * wipe its index (backing up dir first?)
>> >> * configure it to be a backup of the new master
>> >> * make it pull a fresh index over
>> >>
>> >> But, Jan Høydahl suggested using SolrCloud. I'm going to follow up on
>> >> how that might work in that thread.
>> >>
>> >> Upayavira
>> >>
>> >>
>> >> On Sun, 19 Dec 2010 00:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
>> >> wrote:
>> >> > Hi,
>> >> >
>> >> > In the master-slave configuration, I'm trying to figure out how to
>> >> > configure the
>> >> > system setup for master failover.
>> >> >
>> >> > Does solr support master-master setup? From my readings, solr does not.
>> >> >
>> >> > I've read about repeaters as well where the slave can act as a master.
>> >> > When the
>> >> > main master goes down, do the other slaves switch to the repeater?
>> >> >
>> >> > Barring better solutions, I'm thinking about putting 2 masters behind a
>> >> > load
>> >> > balancer.
>> >> >
>> >> > If this is not implemented already, perhaps solr can be updated to
>> >> > support a
>> >> > list of masters for fault tolerance.
>> >> >
>> >> > Tri
>> >>
>> >
>>
>>
>>
>> --
>> Lance Norskog
>> goksron@gmail.com
>>
>
--
Lance Norskog
goksron@gmail.com
Re: master master, repeaters
Posted by Upayavira <uv...@odoko.co.uk>.
I've successfully made extensive use of load balancers in sharded,
replicated slave setups - see [1].
My question is how that might work with a master. You can have a load
balancer, but you'd need to configure it into a 'fail over but please
don't fail back' configuration. I'm not sure if that is possible on the
load balancers we have used. Otherwise, if your master had a five minute
blip, you could have some content going to your backup, then traffic
returning to your master, leading to master/backup out of sync and
content missing from your master index.
It seems to me, unless I am missing something, that while a load
balancer can be useful, it is only as a part of a larger scheme when it
comes to master replication. Or am I missing something?
Upayavira
[1] http://www.slideshare.net/sourcesense/sharded-solr-setup-with-master
On Sun, 19 Dec 2010 22:41 -0800, "Lance Norskog" <go...@gmail.com>
wrote:
> If you have a load balancer available, that is a much cleaner solution
> than anything else. After the main indexer comes back, you have to get
> the current index state to it to start again. But otherwise
>
> On Sun, Dec 19, 2010 at 10:39 AM, Upayavira <uv...@odoko.co.uk> wrote:
> >
> >
> > On Sun, 19 Dec 2010 10:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
> > wrote:
> >> How do we tell the slaves to point to the new master without modifying
> >> the config files? Can we do this while the slave is up, issuing a
> >> command to it?
> >
> > I believe this can be done (details are in
> > http://wiki.apache.org/solr/SolrReplication), but I've not actually done
> > it.
> >
> > Upayavira
> >
> >> --- On Sun, 12/19/10, Upayavira <uv...@odoko.co.uk> wrote:
> >>
> >>
> >> From: Upayavira <uv...@odoko.co.uk>
> >> Subject: Re: master master, repeaters
> >> To: solr-user@lucene.apache.org
> >> Date: Sunday, December 19, 2010, 10:13 AM
> >>
> >>
> >> We had a (short) thread on this late last week.
> >>
> >> Solr doesn't support automatic failover of the master, at least in
> >> 1.4.1. I've been discussing with my colleague (Tommaso) about ways to
> >> achieve this.
> >>
> >> There's ways we could 'fake it', scripting the following:
> >>
> >> * set up a 'backup' master, as a replica of the actual master
> >> * monitor the master for 'up-ness'
> >> * if it fails:
> >> * tell the master to start indexing to the backup instead
> >> * tell the slave(s) to connect to a different master (the backup)
> >> * then, when the master is back:
> >> * wipe its index (backing up dir first?)
> >> * configure it to be a backup of the new master
> >> * make it pull a fresh index over
> >>
> >> But, Jan Høydahl suggested using SolrCloud. I'm going to follow up on
> >> how that might work in that thread.
> >>
> >> Upayavira
> >>
> >>
> >> On Sun, 19 Dec 2010 00:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
> >> wrote:
> >> > Hi,
> >> >
> >> > In the master-slave configuration, I'm trying to figure out how to
> >> > configure the
> >> > system setup for master failover.
> >> >
> >> > Does solr support master-master setup? From my readings, solr does not.
> >> >
> >> > I've read about repeaters as well where the slave can act as a master.
> >> > When the
> >> > main master goes down, do the other slaves switch to the repeater?
> >> >
> >> > Barring better solutions, I'm thinking about putting 2 masters behind a
> >> > load
> >> > balancer.
> >> >
> >> > If this is not implemented already, perhaps solr can be updated to
> >> > support a
> >> > list of masters for fault tolerance.
> >> >
> >> > Tri
> >>
> >
>
>
>
> --
> Lance Norskog
> goksron@gmail.com
>
Re: master master, repeaters
Posted by Lance Norskog <go...@gmail.com>.
If you have a load balancer available, that is a much cleaner solution
than anything else. After the main indexer comes back, you have to get
the current index state to it to start again. But otherwise
On Sun, Dec 19, 2010 at 10:39 AM, Upayavira <uv...@odoko.co.uk> wrote:
>
>
> On Sun, 19 Dec 2010 10:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
> wrote:
>> How do we tell the slaves to point to the new master without modifying
>> the config files? Can we do this while the slave is up, issuing a
>> command to it?
>
> I believe this can be done (details are in
> http://wiki.apache.org/solr/SolrReplication), but I've not actually done
> it.
>
> Upayavira
>
>> --- On Sun, 12/19/10, Upayavira <uv...@odoko.co.uk> wrote:
>>
>>
>> From: Upayavira <uv...@odoko.co.uk>
>> Subject: Re: master master, repeaters
>> To: solr-user@lucene.apache.org
>> Date: Sunday, December 19, 2010, 10:13 AM
>>
>>
>> We had a (short) thread on this late last week.
>>
>> Solr doesn't support automatic failover of the master, at least in
>> 1.4.1. I've been discussing with my colleague (Tommaso) about ways to
>> achieve this.
>>
>> There's ways we could 'fake it', scripting the following:
>>
>> * set up a 'backup' master, as a replica of the actual master
>> * monitor the master for 'up-ness'
>> * if it fails:
>> * tell the master to start indexing to the backup instead
>> * tell the slave(s) to connect to a different master (the backup)
>> * then, when the master is back:
>> * wipe its index (backing up dir first?)
>> * configure it to be a backup of the new master
>> * make it pull a fresh index over
>>
>> But, Jan Høydahl suggested using SolrCloud. I'm going to follow up on
>> how that might work in that thread.
>>
>> Upayavira
>>
>>
>> On Sun, 19 Dec 2010 00:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
>> wrote:
>> > Hi,
>> >
>> > In the master-slave configuration, I'm trying to figure out how to
>> > configure the
>> > system setup for master failover.
>> >
>> > Does solr support master-master setup? From my readings, solr does not.
>> >
>> > I've read about repeaters as well where the slave can act as a master.
>> > When the
>> > main master goes down, do the other slaves switch to the repeater?
>> >
>> > Barring better solutions, I'm thinking about putting 2 masters behind a
>> > load
>> > balancer.
>> >
>> > If this is not implemented already, perhaps solr can be updated to
>> > support a
>> > list of masters for fault tolerance.
>> >
>> > Tri
>>
>
--
Lance Norskog
goksron@gmail.com
Re: master master, repeaters
Posted by Upayavira <uv...@odoko.co.uk>.
On Sun, 19 Dec 2010 10:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
wrote:
> How do we tell the slaves to point to the new master without modifying
> the config files? Can we do this while the slave is up, issuing a
> command to it?
I believe this can be done (details are in
http://wiki.apache.org/solr/SolrReplication), but I've not actually done
it.
Upayavira
> --- On Sun, 12/19/10, Upayavira <uv...@odoko.co.uk> wrote:
>
>
> From: Upayavira <uv...@odoko.co.uk>
> Subject: Re: master master, repeaters
> To: solr-user@lucene.apache.org
> Date: Sunday, December 19, 2010, 10:13 AM
>
>
> We had a (short) thread on this late last week.
>
> Solr doesn't support automatic failover of the master, at least in
> 1.4.1. I've been discussing with my colleague (Tommaso) about ways to
> achieve this.
>
> There's ways we could 'fake it', scripting the following:
>
> * set up a 'backup' master, as a replica of the actual master
> * monitor the master for 'up-ness'
> * if it fails:
> * tell the master to start indexing to the backup instead
> * tell the slave(s) to connect to a different master (the backup)
> * then, when the master is back:
> * wipe its index (backing up dir first?)
> * configure it to be a backup of the new master
> * make it pull a fresh index over
>
> But, Jan Høydahl suggested using SolrCloud. I'm going to follow up on
> how that might work in that thread.
>
> Upayavira
>
>
> On Sun, 19 Dec 2010 00:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
> wrote:
> > Hi,
> >
> > In the master-slave configuration, I'm trying to figure out how to
> > configure the
> > system setup for master failover.
> >
> > Does solr support master-master setup? From my readings, solr does not.
> >
> > I've read about repeaters as well where the slave can act as a master.
> > When the
> > main master goes down, do the other slaves switch to the repeater?
> >
> > Barring better solutions, I'm thinking about putting 2 masters behind a
> > load
> > balancer.
> >
> > If this is not implemented already, perhaps solr can be updated to
> > support a
> > list of masters for fault tolerance.
> >
> > Tri
>
Re: master master, repeaters
Posted by Tri Nguyen <tr...@yahoo.com>.
How do we tell the slaves to point to the new master without modifying the config files? Can we do this while the slave is up, issuing a command to it?
Thanks,
Tri
--- On Sun, 12/19/10, Upayavira <uv...@odoko.co.uk> wrote:
From: Upayavira <uv...@odoko.co.uk>
Subject: Re: master master, repeaters
To: solr-user@lucene.apache.org
Date: Sunday, December 19, 2010, 10:13 AM
We had a (short) thread on this late last week.
Solr doesn't support automatic failover of the master, at least in
1.4.1. I've been discussing with my colleague (Tommaso) about ways to
achieve this.
There's ways we could 'fake it', scripting the following:
* set up a 'backup' master, as a replica of the actual master
* monitor the master for 'up-ness'
* if it fails:
* tell the master to start indexing to the backup instead
* tell the slave(s) to connect to a different master (the backup)
* then, when the master is back:
* wipe its index (backing up dir first?)
* configure it to be a backup of the new master
* make it pull a fresh index over
But, Jan Høydahl suggested using SolrCloud. I'm going to follow up on
how that might work in that thread.
Upayavira
On Sun, 19 Dec 2010 00:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
wrote:
> Hi,
>
> In the master-slave configuration, I'm trying to figure out how to
> configure the
> system setup for master failover.
>
> Does solr support master-master setup? From my readings, solr does not.
>
> I've read about repeaters as well where the slave can act as a master.
> When the
> main master goes down, do the other slaves switch to the repeater?
>
> Barring better solutions, I'm thinking about putting 2 masters behind a
> load
> balancer.
>
> If this is not implemented already, perhaps solr can be updated to
> support a
> list of masters for fault tolerance.
>
> Tri
Re: master master, repeaters
Posted by Upayavira <uv...@odoko.co.uk>.
We had a (short) thread on this late last week.
Solr doesn't support automatic failover of the master, at least in
1.4.1. I've been discussing with my colleague (Tommaso) about ways to
achieve this.
There's ways we could 'fake it', scripting the following:
* set up a 'backup' master, as a replica of the actual master
* monitor the master for 'up-ness'
* if it fails:
* tell the master to start indexing to the backup instead
* tell the slave(s) to connect to a different master (the backup)
* then, when the master is back:
* wipe its index (backing up dir first?)
* configure it to be a backup of the new master
* make it pull a fresh index over
But, Jan Høydahl suggested using SolrCloud. I'm going to follow up on
how that might work in that thread.
Upayavira
On Sun, 19 Dec 2010 00:20 -0800, "Tri Nguyen" <tr...@yahoo.com>
wrote:
> Hi,
>
> In the master-slave configuration, I'm trying to figure out how to
> configure the
> system setup for master failover.
>
> Does solr support master-master setup? From my readings, solr does not.
>
> I've read about repeaters as well where the slave can act as a master.
> When the
> main master goes down, do the other slaves switch to the repeater?
>
> Barring better solutions, I'm thinking about putting 2 masters behind a
> load
> balancer.
>
> If this is not implemented already, perhaps solr can be updated to
> support a
> list of masters for fault tolerance.
>
> Tri