# Es7: Can the seed\_hosts value be dynamically updated? **URL:** \ **Category:** Elasticsearch\ **Created:** [February 28, 2020, 8:04pm UTC](https://discuss.elastic.co/t/es7-can-the-seed-hosts-value-be-dynamically-updated/221482 "2020-02-28T20:04:45Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![UDixit](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/udixit/32/53219_2.png) [@UDixit](https://discuss.elastic.co/u/UDixit)\ **Post date:** [February 28, 2020, 8:04pm UTC](https://discuss.elastic.co/t/es7-can-the-seed-hosts-value-be-dynamically-updated/221482/1 "2020-02-28T20:04:45Z")
During scaledowns, I want to update the seed\_hosts value (to remove the deprovisoing nodes). I want to apply this new value to all the nodes which are still remaining in the cluster. 1. Is it required to update the seed\_hosts value when a scale down occurs? 2. How can I dynamically update the seed\_hosts list? ---
**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\ **Post date:** [February 28, 2020, 8:27pm UTC](https://discuss.elastic.co/t/es7-can-the-seed-hosts-value-be-dynamically-updated/221482/2 "2020-02-28T20:27:31Z")
> [@UDixit](#): > > - Is it required to update the seed\_hosts value when a scale down occurs? No, not required, but it's good practice. Note that the `seed_hosts` value should only mention the master-eligible nodes, and it's rare to want to scale those down (there's normally always three of them). > [@UDixit](#): > > - How can I dynamically update the seed\_hosts list? DNS is a popular choice: create a DNS entry that resolves to the addresses of your three master nodes and set `discovery.seed_hosts` to the name of that entry. Alternatively you can use [file-based discovery](https://www.elastic.co/guide/en/elasticsearch/reference/7.x/modules-discovery-hosts-providers.html#file-based-hosts-provider) or another [discovery plugin](https://www.elastic.co/guide/en/elasticsearch/plugins/7.x/discovery.html). ---
**Author:** ![UDixit](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/udixit/32/53219_2.png) [@UDixit](https://discuss.elastic.co/u/UDixit)\ **Post date:** [February 28, 2020, 8:32pm UTC](https://discuss.elastic.co/t/es7-can-the-seed-hosts-value-be-dynamically-updated/221482/3 "2020-02-28T20:32:21Z")
Unfortunately, I have a different scenario. Each node in my cluster is a master as well as a data node. So a 36 node cluster will have 36 master eligible node and we have to support scale down form 36 -\>1 node as well. I believe in such scenarios, scale down becomes tricky. We need to evacuate these nodes so that quorum doesn't break but I think we should also update the seed\_hosts. ---
**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\ **Post date:** [February 28, 2020, 8:57pm UTC](https://discuss.elastic.co/t/es7-can-the-seed-hosts-value-be-dynamically-updated/221482/4 "2020-02-28T20:57:47Z")
That's very much not a recommended setup. Nonetheless, there are docs describing how to remove master-eligible nodes from the cluster here: [https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-discovery-adding-removing-nodes.html#modules-discovery-removing-nodes](https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-discovery-adding-removing-nodes.html#modules-discovery-removing-nodes) ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 27, 2020, 8:57pm UTC](https://discuss.elastic.co/t/es7-can-the-seed-hosts-value-be-dynamically-updated/221482/5 "2020-03-27T20:57:48Z")
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