# Configuration advice **URL:** \ **Category:** Elasticsearch\ **Created:** [July 25, 2014, 11:14am UTC](https://discuss.elastic.co/t/configuration-advice/18901 "2014-07-25T11:14:25Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Wouter\_van\_Atteveldt](https://avatars.discourse-cdn.com/v4/letter/w/9fc29f/32.png) [@Wouter\_van\_Atteveldt](https://discuss.elastic.co/u/Wouter_van_Atteveldt)\ **Post date:** [July 25, 2014, 11:14am UTC](https://discuss.elastic.co/t/configuration-advice/18901/1 "2014-07-25T11:14:25Z")
Dear elastic users, We use elastic for a document store containing around 100M documents in 200G. We used to run a single elastic node on the same server that functioned as the web server, but this caused a lot of performance issues (and the need of re-indexing all data in case of failure). So, we just acquired two new servers that will function almost exclusively as elastic nodes, both have single SSD disks, 48G ram and a decent modern processor. The web server has 64GB ram and raid 10 spinning disks. The web site is not particularly high-traffic but the elastic queries can be pretty heavy with lots of terms, wildcards, and aggregations (the site is used for scientific text analysis - [http://amcat.vu.nl](http://amcat.vu.nl)) We can imagine three possible configurations: 1. Separate elastic cluster Use the new "elastic" servers only for elastic with data=true,master=true, and use the web server only for other tasks. Advantage: simple; disadvantage: capacity of the existing ("web") server under utilized 1. Use all servers Use all servers for elastic, all with data=true,master=true. Advantage: all resources utilized. Disadvantage: web server has no SSD and also has other tasks, so maybe lower overall performance because it becomes the weakest link? 1. Use web server as 'coordinator' Use the elastic servers as data nodes (with data=true,master=false) and the web server as master node (data=false,master=true). advantage: this seems to use the web server capacity (esp. CPU?) while still having all the data on the SSD's in the new elastic servers disadvantage: more complicated to setup, only a single master node In case (3) is the best option, two more questions: - How do you change a node from data=true to data=false? Just change the config and restart the node? Will it automatically relocate the shards? - What happens if the only master=true node disappears. Will the rest just way for it to come online again? Is the data preserved? What would you recommend? Thanks, -- Wouter -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/c991cff8-52af-49e7-96df-0f7dd6675a4c%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/c991cff8-52af-49e7-96df-0f7dd6675a4c%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [July 25, 2014, 11:29am UTC](https://discuss.elastic.co/t/configuration-advice/18901/2 "2014-07-25T11:29:32Z")
I'd go with option 3, but make all 3 nodes master eligable. That way you prevent complete loss of the cluster and protect against split brain. To change a node role just update the config and restart the service. Shards will be auto promoted (ie replicas to primaries), but you can disable allocation to stop this so when your other node comes up it will just initialise the shards it has locally, this speeds up recovery. Regards, Mark Walkom Infrastructure Engineer Campaign Monitor email: [markw@campaignmonitor.com](mailto:markw@campaignmonitor.com) web: [www.campaignmonitor.com](http://www.campaignmonitor.com) On 25 July 2014 21:14, Wouter van Atteveldt [vanatteveldt@gmail.com](mailto:vanatteveldt@gmail.com) wrote: > Dear elastic users, > > We use elastic for a document store containing around 100M documents in > 200G. We used to run a single elastic node on the same server that > functioned as the web server, but this caused a lot of performance issues > (and the need of re-indexing all data in case of failure). So, we just > acquired two new servers that will function almost exclusively as elastic > nodes, both have single SSD disks, 48G ram and a decent modern processor. > The web server has 64GB ram and raid 10 spinning disks. The web site is not > particularly high-traffic but the elastic queries can be pretty heavy with > lots of terms, wildcards, and aggregations (the site is used for scientific > text analysis - [http://amcat.vu.nl](http://amcat.vu.nl)) > > We can imagine three possible configurations: > > 1. Separate elastic cluster > > Use the new "elastic" servers only for elastic with data=true,master=true, > and use the web server only for other tasks. > Advantage: simple; > disadvantage: capacity of the existing ("web") server under utilized > > 1. Use all servers > > Use all servers for elastic, all with data=true,master=true. > Advantage: all resources utilized. > Disadvantage: web server has no SSD and also has other tasks, so maybe > lower overall performance because it becomes the weakest link? > > 1. Use web server as 'coordinator' > > Use the elastic servers as data nodes (with data=true,master=false) and > the web server as master node (data=false,master=true). > > advantage: this seems to use the web server capacity (esp. CPU?) while > still having all the data on the SSD's in the new elastic servers > disadvantage: more complicated to setup, only a single master node > > In case (3) is the best option, two more questions: > > - How do you change a node from data=true to data=false? Just change the > config and restart the node? Will it automatically relocate the shards? > - What happens if the only master=true node disappears. Will the rest just > way for it to come online again? Is the data preserved? > > What would you recommend? > > Thanks, > > -- Wouter > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/c991cff8-52af-49e7-96df-0f7dd6675a4c%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/c991cff8-52af-49e7-96df-0f7dd6675a4c%40googlegroups.com) > [https://groups.google.com/d/msgid/elasticsearch/c991cff8-52af-49e7-96df-0f7dd6675a4c%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/c991cff8-52af-49e7-96df-0f7dd6675a4c%40googlegroups.com?utm_medium=email&utm_source=footer) > . > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAEM624YR\_L2h4TUTJX20XZqGZzw5ye1B1n0%2BwYZwRFXutPgfcg%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAEM624YR_L2h4TUTJX20XZqGZzw5ye1B1n0%2BwYZwRFXutPgfcg%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Wouter\_van\_Atteveldt](https://avatars.discourse-cdn.com/v4/letter/w/9fc29f/32.png) [@Wouter\_van\_Atteveldt](https://discuss.elastic.co/u/Wouter_van_Atteveldt)\ **Post date:** [July 25, 2014, 12:53pm UTC](https://discuss.elastic.co/t/configuration-advice/18901/3 "2014-07-25T12:53:52Z")
Dear Mark, others, Thanks for the advice! I do have some more questions I'm afraid... On Friday, July 25, 2014 1:30:07 PM UTC+2, Mark Walkom wrote: > I'd go with option 3, but make all 3 nodes master eligable. That way you > prevent complete loss of the cluster and protect against split brain. Right. Is there any advantage to having the 'coordinator' be the master of the cluster? I.e., suppose I restart the coordinator and one of the data nodes becomes master, should I then somehow make the coordinator the master again? > To change a node role just update the config and restart the service. > Shards will be auto promoted (ie replicas to primaries), but you can > disable allocation to stop this so when your other node comes up it will > just initialise the shards it has locally, this speeds up recovery. Well, the current situation is that the shards are divided over the three nodes, each with 1 replica. So, if I change the coordinator into data=false, it will need to distribute the shards it had over the other two nodes so each node has a copy of each shard, so I need to allow allocation, right? Or should I first set # replicates to 2, so the data is copied to all nodes, before setting the coordinator to data=false? Sorry for all the questions, but this part of elastic is new to me and I'm afraid to mess up the index... Thanks, Wouter -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/899f5ae8-202b-4f59-9e20-5ef05148aec7%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/899f5ae8-202b-4f59-9e20-5ef05148aec7%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 1:13am UTC](https://discuss.elastic.co/t/configuration-advice/18901/4 "2017-07-06T01:13:06Z")