I run 3, but i see 2 nodes!

Elastic Stack Elasticsearch
1

Hi again forum.

I try to create a 3-nodes cluster called "myCluster". I ran 2 nodes of Elasticsearch on VirtualBox and another on a Windows pc.

They started and these are their results:

node on VM1

{
  "name" : "Melee",
  "cluster_name" : "myCluster",
  "cluster_uuid" : "_hWtmJWWSMiQQsKRwWMvFA",
  "version" : {
    "number" : "2.4.4",
    "build_hash" : "fcbb46dfd45562a9cf00c604b30849a6dec6b017",
    "build_timestamp" : "2017-01-03T11:33:16Z",
    "build_snapshot" : false,
    "lucene_version" : "5.5.2"
  },
"tagline" : "You Know, for Search"
}

node on VM2

{
  "name" : "ubuntu",
  "cluster_name" : "myCluster",
  "cluster_uuid" : "t-gVE5t3SM233VEriszENw",
  "version" : {
    "number" : "2.4.5",
    "build_hash" : "c849dd13904f53e63e88efc33b2ceeda0b6a1276",
    "build_timestamp" : "2017-04-24T16:18:17Z",
    "build_snapshot" : false,
    "lucene_version" : "5.5.4"
  },
  "tagline" : "You Know, for Search"
}

node on WIN10

{
  "name" : "Archie Corrigan",
  "cluster_name" : "myCluster",
  "cluster_uuid" : "OR57sqDTTeWCPdc67pMHqg",
  "version" : {
    "number" : "2.4.4",
    "build_hash" : "fcbb46dfd45562a9cf00c604b30849a6dec6b017",
    "build_timestamp" : "2017-01-03T11:33:16Z",
    "build_snapshot" : false,
    "lucene_version" : "5.5.2"
  },
  "tagline" : "You Know, for Search"
}

When i call a get to my cluster on PostMan, i see:

for node1

{
  "cluster_name": "myCluster",
  "status": "green",
  "timed_out": false,
  "number_of_nodes": 1,
  "number_of_data_nodes": 1,
  "active_primary_shards": 0,
  "active_shards": 0,
  "relocating_shards": 0,
  "initializing_shards": 0,
  "unassigned_shards": 0,
  "delayed_unassigned_shards": 0,
  "number_of_pending_tasks": 0,
  "number_of_in_flight_fetch": 0,
  "task_max_waiting_in_queue_millis": 0,
  "active_shards_percent_as_number": 100
}

for node2

{
  "cluster_name": "myCluster",
  "status": "green",
  "timed_out": false,
  "number_of_nodes": 2,
  "number_of_data_nodes": 2,
  "active_primary_shards": 0,
  "active_shards": 0,
  "relocating_shards": 0,
  "initializing_shards": 0,
  "unassigned_shards": 0,
  "delayed_unassigned_shards": 0,
  "number_of_pending_tasks": 0,
  "number_of_in_flight_fetch": 0,
  "task_max_waiting_in_queue_millis": 0,
  "active_shards_percent_as_number": 100
}

for node3

{
  "cluster_name": "myCluster",
  "status": "green",
  "timed_out": false,
  "number_of_nodes": 2,
  "number_of_data_nodes": 2,
  "active_primary_shards": 0,
  "active_shards": 0,
  "relocating_shards": 0,
  "initializing_shards": 0,
  "unassigned_shards": 0,
  "delayed_unassigned_shards": 0,
  "number_of_pending_tasks": 0,
  "number_of_in_flight_fetch": 0,
  "task_max_waiting_in_queue_millis": 0,
  "active_shards_percent_as_number": 100
}

Why i don't see always 3 nodes, although i hava the same cluster on they?

Thanks a lot!!

2

Node 1 appears to be running as a single node cluster, and as its status is green,( assuming all nodes are master eligible) I suspect you have not set minimum_master_nodes to 2 in order too avoid split brain scenarios? What does the configuration of the nodes look like?

3

This is configuration of the nodes, it is similar for all three nodes:

# ======================== Elasticsearch Configuration =========================
#
# 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 see the documentation for further information on configuration options:
# <http://www.elastic.co/guide/en/elasticsearch/reference/current/setup-configuration.html>
#
# ---------------------------------- Cluster -----------------------------------
#
# Use a descriptive name for your cluster:
#
cluster.name: myCluster
#
# ------------------------------------ Node ------------------------------------
#
# Use a descriptive name for the node:
#
# node.name: node-1
#
# Add custom attributes to the node:
#
# node.rack: r1
#
# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
# path.data: /path/to/data
#
# Path to log files:
#
# path.logs: /path/to/logs
#
# ----------------------------------- Memory -----------------------------------
#
# Lock the memory on startup:
#
# bootstrap.memory_lock: true
#
# Make sure that the `ES_HEAP_SIZE` environment variable 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):
#
network.host: 192.168.2.133
#
# Set a custom port for HTTP:
#
# http.port: 9200
#
# For more information, see the documentation at:
# <http://www.elastic.co/guide/en/elasticsearch/reference/current/modules-network.html>
#
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when new node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
# discovery.zen.ping.unicast.hosts: ["192.168.2.113", "192.168.2.133", "192.168.2.134"]
#
# Prevent the "split brain" by configuring the majority of nodes (total number of nodes / 2 + 1):
#
discovery.zen.minimum_master_nodes: 2
#
# For more information, see the documentation at:
# <http://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery.html>
#
# ---------------------------------- Gateway -----------------------------------
#
# Block initial recovery after a full cluster restart until N nodes are started:
#
# gateway.recover_after_nodes: 3
#
# For more information, see the documentation at:
# <http://www.elastic.co/guide/en/elasticsearch/reference/current/modules-gateway.html>
#
# ---------------------------------- Various -----------------------------------
#
# Disable starting multiple nodes on a single system:
#
# node.max_local_storage_nodes: 1
#
# Require explicit names when deleting indices:
#
# action.destructive_requires_name: true

The only difference between the 3 files is only about network.host

Now, with discovery.zen.minimum_master_nodes: 2 uncommented, i get this results from postman only on the node that see 1 one in the cluster:

{
  "error": {
    "root_cause": [
      {
        "type": "master_not_discovered_exception",
        "reason": null
      }
    ],
    "type": "master_not_discovered_exception",
    "reason": null
  },
  "status": 503
}

Thanks for the help!

4

Check that you can telnet to port 9300 on all nodes from each VM/host. This could be a connectivity issue.

1 Like
5

You're right!

None of my nodes can connect to 192.168.2.134:9300, not even the node itself!

I try to disable firewall but i've got the same error on telnet Connection refused

Any suggestion? Thanks!

6

I risolved the issue! The transport tcp port for that node was 9330 and not 9300. Changing this setting, it works fine! Thank you for your help!

7

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