# Master\_not\_discovered\_exception

**URL:** <https://discuss.elastic.co/t/master-not-discovered-exception/280225>\
**Category:** Elasticsearch\
**Created:** [August 2, 2021, 1:16pm UTC](https://discuss.elastic.co/t/master-not-discovered-exception/280225 "2021-08-02T13:16:08Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![prithvirajsivarajan](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@prithvirajsivarajan](https://discuss.elastic.co/u/prithvirajsivarajan)\
**Post date:** [August 2, 2021, 1:16pm UTC](https://discuss.elastic.co/t/master-not-discovered-exception/280225/1 "2021-08-02T13:16:08Z")

</div>

I have an elasticsearch cluster with 2 nodes. When I stop elasticsearch instance on master node the other one is not becoming master automatically. It gives the master not discovered exception

elasticsearch.yml on node-1(master)

```auto
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
cluster.name: dps_dashboard
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
node.name: node-1
#
#node.master: true
#node.data: false
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
path.data: /apps/esdata/elasticsearch/
#
# Path to log files:
#
path.logs: /var/log/elasticsearch
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
#bootstrap.memory_lock: true
#
# Make sure that the heap size is set to about half the memory available
# on the system and that the owner of the process is allowed to use this
# limit.
#
# Elasticsearch performs poorly when the system is swapping the memory.
#
# ---------------------------------- Network -----------------------------------
#
# By default Elasticsearch is only accessible on localhost. Set a different
# address here to expose this node on the network:
#
network.host: [_local_, _site_]
#
#network.publish_host: 10.130.164.{IP1}
#
# By default Elasticsearch listens for HTTP traffic on the first free port it
# finds starting at 9200. Set a specific HTTP port here:
#
http.port: 9200
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
discovery.seed_hosts: ["10.130.164.{IP1}", "10.130.164.{IP2}"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
cluster.initial_master_nodes: ["10.130.164.{IP1}"]
#
# For more information, consult the discovery and cluster formation module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true
#

```

elasticsearch.yml on node-2

```auto
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
cluster.name: dps_dashboard
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
node.name: node-2
#
#node.master: false
#node.data: true
#
# Add custom attributes to the node:
#
#node.attr.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
path.data: /apps/esdata/elasticsearch/
#
# Path to log files:
#
path.logs: /var/log/elasticsearch
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
#bootstrap.memory_lock: true
#
# Make sure that the heap size is set to about half the memory available
# on the system and that the owner of the process is allowed to use this
# limit.
#
# Elasticsearch performs poorly when the system is swapping the memory.
#
# ---------------------------------- Network -----------------------------------
#
# By default Elasticsearch is only accessible on localhost. Set a different
# address here to expose this node on the network:
#
network.host: [_local_, _site_]
#
#network.publish_host: 10.130.164.{IP2}
#
# By default Elasticsearch listens for HTTP traffic on the first free port it
# finds starting at 9200. Set a specific HTTP port here:
#
http.port: 9200
#
# For more information, consult the network module documentation.
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
discovery.seed_hosts: ["10.130.164.{IP1}", "10.130.164.{IP2}"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
cluster.initial_master_nodes: ["10.130.164.{IP1}"]
#
# For more information, consult the discovery and cluster formation module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true

```

---

<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [August 2, 2021, 1:31pm UTC](https://discuss.elastic.co/t/master-not-discovered-exception/280225/2 "2021-08-02T13:31:30Z")

</div>

That is expected as a majority of master eligible nodes are required in order to elect a master. The majority of 2 is 2 so both nodes need to be up for the cluster to be operation, which is why clusters with at least 3 master eligible nodes are recommended/required in order to get some high availability. Please see [the docs](https://www.elastic.co/guide/en/elasticsearch/reference/7.13/high-availability-cluster-small-clusters.html) for more details.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [August 30, 2021, 1:31pm UTC](https://discuss.elastic.co/t/master-not-discovered-exception/280225/3 "2021-08-30T13:31:32Z")

</div>

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