How does ELK (Elastichsearch, Logstash, Kibana) work - elasticsearch

How are events indexed and stored by Elasticsearch when using ELK (Elastichsearch, Logstash, Kibana)
How does Elasticsearch work in ELK

Looks like you got downvoted for not just reading up at elastic.co, but...
logstash picks up unstructured data from log files and other sources, transforms it into structured data, and inserts it into elasticsearch.
elasticsearch is the document repository. While it's not useful for log information, it's a text engine at heart and can analyze the data (tokenization, stop words, stemming, etc).
kibana reads from elasticsearch and allows you to explore the data and make dashboards.
That's the 30,000-ft overview.

Elasticsearch have the function of database on ELK Stack.
You can read more information about Elasticsearch and ELK Stack here: https://www.elastic.co/guide/en/elasticsearch/guide/current/index.html.

first of all you will have logs file that you used to write system logs on it
for example when you add new record to database you will write the record in any form you need to log file like
date,"name":"system","serial":"1234" .....
after that you will add your configuration in logstash to parse the data from the logs
and it will be like
name : system
.....
and the data will saved in elastic search
kibana is used to preview the elastic search data
and you can use send a request to elasticsearch with the required query and get your data from it

Related

How data is getting mapped in Elastic search in ELK?

I am new to the ELK and i am in the progress of learning it. In my project, they are importing the data from Amazon S3 -> File Beat -> logstash -> Elastic search -> Kibanna.
In the logstash file, they have directly importing the data and sending to the Elastic search something like below and there was no indexes mentioned in the config file,
output elasticsearch
{
hosts => ["http://localhost:9200"]
}
In Amazon s3, we have logs from Salesforce and in future we are going to implement from multiple sources.
In Elastic search, i could see 41 indexes(Used Get Curl script) is present. Assume if we keep the same setup in logstash, then all logs(Multiple sources) will be sent to elastic search in same manner. I would like to know how the data is getting mapped to the particular index in elastic search ??
In many tutorials, they have given indexes in the logstash config file so in kibanna we could see the index name along with timestamp. I have tried to check by placing a sample Mulesoft log file in Amazon S3 but i cant able to find those data in Kibanna. So shall i need to create one more new index with a name Mule along with mappings??
There is no ELK expert in my project so please guide me on how to approach this one or any references will be more helpful.
This page (https://www.elastic.co/guide/en/logstash/current/plugins-outputs-elasticsearch.html) documents Logstash's Elasticsearch output plugin.
As you can see in the Configuration Options section, the option index is not mandatory. If this option is not specified, its default-value is logstash-%{+YYYY.MM.dd}.
With that being said, the documents will get indexed into indices with the prefix 'logstash-' followed by the date of ingestion. For example:
logstash-2020.04.07
logstash-2020.04.08
Since someone in your organization has chosen to go with the default value, this option can be left out. This explains why you can't find a particular index name in the Logstash configuration. If you need to index documents into different indices, then you'd have to set a particular value for the index option.
Elasticsearch will automatically create these indices with a dynamic mapping (https://www.elastic.co/guide/en/elasticsearch/reference/current/dynamic-mapping.html) if you haven't setup an explicit mapping via index templates in advance. In order to see the data in kibana, you first need to create an index pattern matching the index name.
I hope I could help you.

How to get geo-location based on list of ip addresses in Elasticsearch

I have a bunch of log files that are already Indexed in Elastic. Is there a way I can create a new field within each JSON document of my index and run something to get the geo-location of each IP address?
I know about Logstash, but I would like to keep this in Elastic. Is that possible, if so, how?
Thanks!
I suggest you this nice tutorial :
How To Map User Location with GeoIP and ELK (Elasticsearch, Logstash, and Kibana)
I hope you can make it.

How to check if a field value exists before inserting in elasticsearch?

I have a working ELK with input coming from filebeat prospecting several log files and sending them to logstash. Logstash retrieves the stream, filters that in order to match lines with some fields and then sends them into elasticsearch.
Now I would like to check before output to elasticsearch, if for a coming entry into elasticsearch, there is already an existing document. If yes, I want to apply another output plugin instead of elasticsearch.

Where / How ElasticSearch stores logs received from Logstash?

Disclaimer: I am very new to ELK Stack, so this question can be very basic.
I am setting up ELK stack now. I have below basic questions about ElasticSearch.
What is the storage model elastic search is following?
For example Oracle is using relational model ,Alfresco is using "document model" and Apache Jackrabbit is using "hierarchial model"
2.Log data stored in elastic search is persistent/permanent ? Or ElasticSearch deletes log data after certain period?
3.How we will manage/backup this data?
4.Log/data files in Elastic Search is human-readable?
Any help/route to documentation will be appreciated.
the storage model is a Document model. Everything is a document. The documents are of a particular type and they are stored in an index.
Data send to ES is stored on disk. It can be then read, searched or deleted through a REST API.
The Data is managed through the rest API. Usually for log centralisation, the logs are stored in date-based index (one index for today, one for yesterday and so on), so to delete the logs from one day, you delete the relevant index. Curator can help in this case. ES offers a backup and restore module.
To access the data in ES, you'll have to use the REST API or use the Kibana client.
Documentation:
https://www.elastic.co/guide/en/elasticsearch/guide/current/index.html
https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html

Indexing logs with es-hadoop

I am new to elasticsearch and want to index my website logs which are stored on HDFS for fast querying.
I have a well structured pipeline which runs a script every 20 minutes to ingest the data into HDFS.
I want to integrate elasticsearch with it, so that it also indexes these logs based on particular field(s) and thereby giving faster query results using spark SQL.
So, my question is, can I index my data based on particular field(s) only?
Also, my logs are saved in avro file format. Does es provides a way to directly index avro serialized data or do I need to convert it into some other format?
Thank you in advance.
I would suggest you to look at Elasticsearch, Logstash and Kibana stack that should be good enough to full fill your requirement. Putting it on HDFS and then using ES would be additional overhead.
Instead, you can use Logstash to pump data into ES, index on whatever fields you wish to query and build easy dashboards in less than 10 minutes of exercise. Take a look at this tutorial for better step-by-step guide.
http://hadooptutorials.co.in/tutorials/elasticsearch/log-analytics-using-elasticsearch-logstash-kibana.html

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