How can you remove node ID form cluster?

Theoooooo · May 24, 2019, 12:44pm

Hello Everyone,

i'm in a situation i've never seen anywhere else and i really need you help on this one.

I decomissioned a master eligible node while following the guide : https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery-adding-removing-nodes.html

My plan was to remove the old node and add a new node with the same IP.
But after all the steps, i tried to add my new freshly installed elasticsearch node on a new VM with the same IP but the ID that is bind to the IP is still present in the cluster.
Because of that, unstead of joining the cluster, the node is rejected of the cluster because the ID does not match the IP and create a cluster on it's own preventing me of adding an ingest node to my existing cluster.

I wasn't been able to found anywhere how to remove the ID from the cluster and the previous node has been deleted so i can't recover it and tried to fix the problem about it.

In my config file, i assigned the original master node to this IP because it will serve as a master and ingest node that will redirect the data on the 2 other nodes.

The new nodes is just never discovering the existing cluster.

Config file of the three nodes in the cluster :

#
# NOTE: Elasticsearch comes with reasonable defaults for most settings.
#       Before you set out to tweak and tune the configuration, make sure you
#       understand what are you trying to accomplish and the consequences.
#
# The primary way of configuring a node is via this file. This template lists
# the most important settings you may want to configure for a production cluster.
#
# Please consult the documentation for further information on configuration options:
# https://www.elastic.co/guide/en/elasticsearch/reference/index.html
#
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
cluster.name: STACK_EFK
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
node.name: cyres-elas01
#
# 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: /data
#
# 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 -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
#
cluster.initial_master_nodes:
        - 172.31.18.212
#
#
network.host: 172.31.18.212
#
# Set a custom port for HTTP:
#
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: ["172.31.18.211", "172.31.18.212", "172.31.18.213"]
#
discovery.zen.minimum_master_nodes: 2
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
#cluster.initial_master_nodes: ["node-1", "node-2"]
#
# For more information, consult the discovery and cluster formation module documentation.
#
# ---------------------------------- Gateway -----------------------------------
#
# Block initial recovery after a full cluster restart until N nodes are started:
#
#gateway.recover_after_nodes: 3
#
# For more information, consult the gateway module documentation.
#
# ---------------------------------- Various -----------------------------------
#
# Require explicit names when deleting indices:
#
#action.destructive_requires_name: true
#
xpack.monitoring.enabled: false

xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.keystore.path: certs/stack-gefk-certificates.p12
xpack.security.transport.ssl.truststore.path: certs/stack-gefk-certificates.p12

Just to precise every node has the same config file (expect for the network.host part and the node name), the firewall has been disable on the three node for testing purpose.

Theoooooo · May 24, 2019, 1:30pm

EDIT : Even if i try to add another node with another IP to the cluster, it's doing the same thing. Not discovering the cluster and create it's own cluster in the node i try to add.
I just can't add anymore node to my cluster.
I don't have any errors on the 2 other node while starting the new one. I don't even know what is going on behind

DavidTurner · May 24, 2019, 2:56pm

You are asking the node to form a new cluster on its own here:

If you want your node to join an existing cluster, you shouldn't be setting this. From the docs:

This is only required the very first time the cluster starts up: nodes that have already joined a cluster store this information in their data folder and freshly-started nodes that are joining an existing cluster obtain this information from the cluster’s elected master.