# WARNING: master node with node.data=false deletes cluster
**URL:** https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227
**Category:** Elasticsearch
**Created:** [August 23, 2011, 3:07pm UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227 "2011-08-23T15:07:50Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Jurgen\_kartnaller](https://discuss.elastic.co/u/Jurgen_kartnaller)
#### Post date: [August 23, 2011, 3:07pm UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227/1 "2011-08-23T15:07:50Z")
If you have node.data set to false it is important to set node.master to
false.
If a none data node becomes a master the whole cluster data gets lost on a
restart!
@Shay
It would be a good idea to automatically set node.master to false if
node.data is set to true.
Jürgen
---
### Author:  [@kimchy](https://discuss.elastic.co/u/kimchy)
#### Post date: [August 23, 2011, 6:57pm UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227/2 "2011-08-23T18:57:07Z")
This configuration should is valid and should not result in loss of data. I
wonder if you hit something I fixed in master/0.17 branch:
[Single node rolling restart into a new node can cause metadata loss · Issue #1249 · elastic/elasticsearch · GitHub](https://github.com/elasticsearch/elasticsearch/issues/1249).
Can you provide the steps that led to loosing the data? I would like to
recreate it. For example: Start the non\_data/master node, then start a
data/non\_master node, index some sample data, shut it down, start it in the
same order, ... .
On Tue, Aug 23, 2011 at 6:07 PM, Jürgen kartnaller \<
[juergen.kartnaller@gmail.com](mailto:juergen.kartnaller@gmail.com)\> wrote:
> If you have node.data set to false it is important to set node.master to
> false.
>
> If a none data node becomes a master the whole cluster data gets lost on a
> restart!
>
> @Shay
> It would be a good idea to automatically set node.master to false if
> node.data is set to true.
>
> Jürgen
---
### Author:  [@Jurgen\_kartnaller](https://discuss.elastic.co/u/Jurgen_kartnaller)
#### Post date: [August 24, 2011, 5:59am UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227/3 "2011-08-24T05:59:29Z")
We are using version 17.6.
The reason to restart the cluster was an update of a plugin.
Here's the scenario:
- shut down the cluster
- start the none data node (node.data = false, no other node settings)
At this time this node was marked as master Node in BigDesk
- start the data nodes
-\> data gone
Unfortunately I can not reproduce this scenario ☹
On Tue, Aug 23, 2011 at 8:57 PM, Shay Banon [kimchy@gmail.com](mailto:kimchy@gmail.com) wrote:
> This configuration should is valid and should not result in loss of data. I
> wonder if you hit something I fixed in master/0.17 branch:
> [Single node rolling restart into a new node can cause metadata loss · Issue #1249 · elastic/elasticsearch · GitHub](https://github.com/elasticsearch/elasticsearch/issues/1249).
>
> Can you provide the steps that led to loosing the data? I would like to
> recreate it. For example: Start the non\_data/master node, then start a
> data/non\_master node, index some sample data, shut it down, start it in the
> same order, ... .
>
> On Tue, Aug 23, 2011 at 6:07 PM, Jürgen kartnaller \<
> [juergen.kartnaller@gmail.com](mailto:juergen.kartnaller@gmail.com)\> wrote:
>
> > If you have node.data set to false it is important to set node.master to
> > false.
> >
> > If a none data node becomes a master the whole cluster data gets lost on a
> > restart!
> >
> > @Shay
> > It would be a good idea to automatically set node.master to false if
> > node.data is set to true.
> >
> > Jürgen
---
### Author:  [@kimchy](https://discuss.elastic.co/u/kimchy)
#### Post date: [August 26, 2011, 2:29pm UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227/4 "2011-08-26T14:29:58Z")
I will try and reproduce it as well. I have several automated tests that do
just that, and they pass... . If you manage to get it to happen, would love
to hear it.
On Wed, Aug 24, 2011 at 8:59 AM, Jürgen kartnaller \<
[juergen.kartnaller@gmail.com](mailto:juergen.kartnaller@gmail.com)\> wrote:
> We are using version 17.6.
>
> The reason to restart the cluster was an update of a plugin.
>
> Here's the scenario:
>
> - shut down the cluster
> - start the none data node (node.data = false, no other node settings)
> At this time this node was marked as master Node in BigDesk
> - start the data nodes
>
> -\> data gone
>
> Unfortunately I can not reproduce this scenario ☹
>
> On Tue, Aug 23, 2011 at 8:57 PM, Shay Banon [kimchy@gmail.com](mailto:kimchy@gmail.com) wrote:
>
> > This configuration should is valid and should not result in loss of data.
> > I wonder if you hit something I fixed in master/0.17 branch:
> > [Single node rolling restart into a new node can cause metadata loss · Issue #1249 · elastic/elasticsearch · GitHub](https://github.com/elasticsearch/elasticsearch/issues/1249).
> >
> > Can you provide the steps that led to loosing the data? I would like to
> > recreate it. For example: Start the non\_data/master node, then start a
> > data/non\_master node, index some sample data, shut it down, start it in the
> > same order, ... .
> >
> > On Tue, Aug 23, 2011 at 6:07 PM, Jürgen kartnaller \<
> > [juergen.kartnaller@gmail.com](mailto:juergen.kartnaller@gmail.com)\> wrote:
> >
> > > If you have node.data set to false it is important to set node.master to
> > > false.
> > >
> > > If a none data node becomes a master the whole cluster data gets lost on
> > > a restart!
> > >
> > > @Shay
> > > It would be a good idea to automatically set node.master to false if
> > > node.data is set to true.
> > >
> > > Jürgen
---
### Author:  [@Jurgen\_kartnaller](https://discuss.elastic.co/u/Jurgen_kartnaller)
#### Post date: [August 26, 2011, 5:33pm UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227/5 "2011-08-26T17:33:55Z")
The cluster consist of 12 data nodes and one none data node.
This is what happend before the cluster restart:
We tried to stop the cluster because all nodes where running on a high load
without a reason.
First we used the \_shutdown API without success.
Then we used the shutdown script on all nodes.
On Fri, Aug 26, 2011 at 4:29 PM, Shay Banon [kimchy@gmail.com](mailto:kimchy@gmail.com) wrote:
> I will try and reproduce it as well. I have several automated tests that do
> just that, and they pass... . If you manage to get it to happen, would love
> to hear it.
>
> On Wed, Aug 24, 2011 at 8:59 AM, Jürgen kartnaller \<
> [juergen.kartnaller@gmail.com](mailto:juergen.kartnaller@gmail.com)\> wrote:
>
> > We are using version 17.6.
> >
> > The reason to restart the cluster was an update of a plugin.
> >
> > Here's the scenario:
> >
> > - shut down the cluster
> > - start the none data node (node.data = false, no other node settings)
> > At this time this node was marked as master Node in BigDesk
> > - start the data nodes
> >
> > -\> data gone
> >
> > Unfortunately I can not reproduce this scenario ☹
> >
> > On Tue, Aug 23, 2011 at 8:57 PM, Shay Banon [kimchy@gmail.com](mailto:kimchy@gmail.com) wrote:
> >
> > > This configuration should is valid and should not result in loss of data.
> > > I wonder if you hit something I fixed in master/0.17 branch:
> > > [Single node rolling restart into a new node can cause metadata loss · Issue #1249 · elastic/elasticsearch · GitHub](https://github.com/elasticsearch/elasticsearch/issues/1249).
> > >
> > > Can you provide the steps that led to loosing the data? I would like to
> > > recreate it. For example: Start the non\_data/master node, then start a
> > > data/non\_master node, index some sample data, shut it down, start it in the
> > > same order, ... .
> > >
> > > On Tue, Aug 23, 2011 at 6:07 PM, Jürgen kartnaller \<
> > > [juergen.kartnaller@gmail.com](mailto:juergen.kartnaller@gmail.com)\> wrote:
> > >
> > > > If you have node.data set to false it is important to set node.master to
> > > > false.
> > > >
> > > > If a none data node becomes a master the whole cluster data gets lost on
> > > > a restart!
> > > >
> > > > @Shay
> > > > It would be a good idea to automatically set node.master to false if
> > > > node.data is set to true.
> > > >
> > > > Jürgen
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 3:55am UTC](https://discuss.elastic.co/t/warning-master-node-with-node-data-false-deletes-cluster/5227/6 "2017-07-06T03:55:53Z")