Elasticsearch 6.7.0 status Yellow in Magento 2.3.1

Elastic Stack Elasticsearch
1

I have an Ubuntu 18.04 system installed on a Digital Ocean server. I have installed the Magento 2.3.1 version. I have installed Java and Elasticsearch using the following commands:

JAVA

sudo add-apt-repository -y ppa:webupd8team/java
sudo apt-get -y update
sudo apt-get install -y oracle-java8-installer

ELASTICSEARCH

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
echo "deb https://artifacts.elastic.co/packages/6.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-6.x.list
sudo apt update
sudo apt install elasticsearch
Edit this file: /etc/elasticsearch/elasticsearch.yml and add this info: network.host: localhost
sudo systemctl daemon-reload
sudo systemctl start elasticsearch
sudo systemctl enable elasticsearch

If I execute this command:

curl -XGET -H "Content-Type: application/json" http://localhost:9200/_cluster/health?pretty=true

This is the result:

{
"cluster_name" : "elasticsearch",
"status" : "yellow",
"timed_out" : false,
"number_of_nodes" : 1,
"number_of_data_nodes" : 1,
"active_primary_shards" : 20,
"active_shards" : 20,
"relocating_shards" : 0,
"initializing_shards" : 0,
"unassigned_shards" : 20,
"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" : 50.0
}

The status is yellow and unassigned_shards is 20. How can I solve this problem?

2

The status is yellow because you have unassigned shards. The allocation explain API is normally a good way to explain why they are unassigned.

In this case you have one node, but I think your indices all have number_of_replicas: 1 (which is the default). The primary of each shard is assigned to your one node, but there is no other node to hold the replica. Either add a second node to your cluster, or set number_of_replicas: 0 on each index.

1 Like
3

Thank you very much for your reply. I am very new to Elasticsearch, could you tell me how I can solve this problem please?

4

Here:

See also Update index settings API | Elasticsearch Guide [8.11] | Elastic and Index Templates | Elasticsearch Guide [6.7] | Elastic

5

Thank you very much for your advice. Could you tell me a website where you can read the difference between creating a new node and putting each index to zero? (Or if you can explain it to me I would appreciate it)

Is it possible that the slowness of my website is due to this? (my website is a Magento 2)

6

Sure, there's loads of introductory material linked from the pages I've suggested:

https://www.elastic.co/webinars/getting-started-elasticsearch?baymax=rtp&elektra=docs&storm=top-video

https://www.elastic.co/guide/en/elasticsearch/reference/current/getting-started-concepts.html

It's unlikely that the yellow health status is the cause is your website's performance issues, however.

7

@DavidTurner Do you think this warning is easy to solve?

warning: Falling back to java on path. This behavior is deprecated. Specify JAVA_HOME

When I execute this order this is the result:

$ java -version
java version "1.8.0_201"
Java(TM) SE Runtime Environment (build 1.8.0_201-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.201-b09, mixed mode)

and:

$ echo $JAVA_HOME
/usr/lib/jvm/java-8-oracle

How can I solve this problem?

8

@DavidTurner I have been researching and I can not add a new node from the terminal, could you help me please?

9

Sure, if you cannot add a new node then the other alternative is to set number_of_replicas: 0 on all your indices. There's a link above about how to adjust the settings on an index, but here it is again:

10

For this, I used this sentence:

curl -XPUT "localhost:9200/*/_settings" -H 'Content-Type: application/json' -d' { "index" : { "number_of_replicas":0 } '

But I received this error:

{"error":{"root_cause":[{"type":"json_e_o_f_exception","reason":"Unexpected end-of-input: expected close marker for Object (start marker at [Source: org.elasticsearch.transport.netty4.ByteBufStreamInput@3f073516; line: 1, column: 2])\n at [Source: org.elasticsearch.transport.netty4.ByteBufStreamInput@3f073516; line: 1, column: 87]"}],"type":"json_e_o_f_exception","reason":"Unexpected end-of-input: expected close marker for Object (start marker at [Source: org.elasticsearch.transport.netty4.ByteBufStreamInput@3f073516; line: 1, column: 2])\n at [Source: org.elasticsearch.transport.netty4.ByteBufStreamInput@3f073516; line: 1, column: 87]"},"status":500}

11

The key part of the error message is expected close marker for Object: your JSON is syntactically invalid because it is missing a closing brace. Try this:

{ "index" : { "number_of_replicas":0 }}

1 Like
12

It has been fixed! Thank you so much for your help! One more question, Magento now needs to use Elasticsearch to manage the database. I have Elasticsearch installed on the same server as Magento. Could you tell me if this is a good practice?

13

It's not unusual for a small system. I don't know anything about Magento, I'm afraid, but as a general principle you'll have to be aware of a couple of issues:

  • you only have the resources of a single server available to do all the work. Perhaps this is enough, perhaps it's not - it depends on how heavily you're using it.

  • you only have one Elasticsearch node. If it breaks (e.g. the disk becomes corrupt) then you will lose data.

14

How can a node be broken and data lost?

15

Disks are one of the least reliable components of a server, and they fail (or silently corrupt data) with surprising frequency. A good quality disk might be within spec if it only corrupts one in every 10^14 bits, but that's only 11TB of data, and some people report much higher error rates.

16

My disk is SSD, this helps the node not break?

17

No, SSDs are also not 100% reliable, and their reliability degrades over time.

18

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