Elastic search is a search engine, according to Wikipedia. This implies it is not a database, and does not store the data it is indexing (but presumably does store its indexes)
There are presumably 2 ways to get data into Es. Log shipping or directly via api.
Let’s say my app wants to write an old fashioned log file entry:
Logger.error(now() + “ something bad happened in module “ + module + “;” + message”
This could either write to a file or put the data directly in es using a rest api.
If it was done via rest api, does es store the entire log message, in which case you dont need to waste disk writing the logs to files for compliance etc. Or does it only index the data, so you need to keep a separate copy? If you delete or move the original log file, how does es know, and is what it Deos store still usefull?
If you write to a log file, then use log stash or similar to “put the log data in es” does es store the entire log file as well as any indexes?
How does es parse or index arbitrary log files? Does it treat a log line as a single string, or does it require logs to have a specific format such as cvs or Jason?
Does anyone know of a resource with this key info?
Elasticsearch does store the data you are indexing.
When you ingest data into elasticsearch, this data is stored in one or more index and then it can be searched. To be able to search something with elasticsearch you need to store the data in elasticsearch, it can not for example search on external files.
In your example, if you have an app sending logs do elasticsearch, it will store the entire message you send and after it is in elasticsearch you don't need the original log anymore.
If you need to parse your documents in different fields you can do it before sending the log to elasticsearch as a json document, use logstash to do this or use an ingest pipeline in elasticsearch.
A good starting point to know more about how it works is the official documentation
Related
I am trying to Use my Elastic search server installed in my local machine to use Postman .i.e., With the help of Postman I want to Post Data and retrieve it with a get operation but unable to do it as I am getting error unknown key [High] for create index
So please help me with the same.
If you want to add a document to your index,
your url should look something like this ( for document ID 1 ) :
PUT http://localhost:9200/test/_doc/1
A good place to start :
https://www.elastic.co/guide/en/elasticsearch/reference/current/getting-started-index.html
For indexing document in the index
PUT http://localhost:9200/my_index/_doc/1
Retrieving indexed document
GET http://localhost:9200/my_index/_doc/1
Introduction:
Elasticsearch is a distributed, RESTful search and analytics engine capable of addressing a growing number of use cases. As the heart of the Elastic Stack, it centrally stores your data for lightning fast search, fine‑tuned relevancy, and powerful analytics that scale with ease.
Kibana is a free and open user interface that lets you visualize your Elasticsearch data and navigate the Elastic Stack. Do anything from tracking query load to understanding the way requests flow through your apps.
Logstash is a free and open server-side data processing pipeline that ingests data from a multitude of sources, transforms it, and then sends it to your favorite “stash.” .
Elasticsearch exposes itself through rest API so in this case you don't have to use logstash as we are directly adding data to elastic search
How to add it directly
you can create an index and type using :
{{url}}/index/type
where index is like a table and type is like just a unique data type that we will be storing to the index. Eg {{url}/movielist/movie
https://praveendavidmathew.medium.com/visualization-using-kibana-and-elastic-search-d04b388a3032
Consider the following use case:
I want the information from one particular log line to be indexed into Elasticsearch, as a document X.
I want the information from some log line further down the log file to be indexed into the same document X (not overriding the original, just adding more data).
The first part, I can obviously achieve with filebeat.
For the second, does anyone have any idea about how to approach it? Could I still use filebeat + some pipeline on an ingest node for example?
Clearly, I can use the ES API to update the said document, but I was looking for some solution that doesn't require changes to my application - rather, it is all possible to achieve using the log files.
Thanks in advance!
No, this is not something that Beats were intended to accomplish. Enrichment like you describe is one of the things that Logstash can help with.
Logstash has an Elasticsearch input that would allow you to retrieve data from ES and use it in the pipeline for enrichment. And the Elasticsearch output supports upsert operations (update if exists, insert new if not). Using both those features you can enrich and update documents as new data comes in.
You might want to consider ingesting the log lines as is to Elasticearch. Then using Logstash, build a separate index that is entity specific and driven based on data from the logs.
Basic usecase that we are trying to solve is for users to be able to search from the contents of the log file .
Lets say a simple situation where user searches for a keyword and this is present in a log file which i want to render it back to the user.
We plan to use ElasticSearch for handling this. The idea that i have in mind is to use elastic search as a mechanism to store the indexed log files.
Having this concept in mind, i went through https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html
Couple of questions i have,
1) I understand the input provided to elastic search is a JSON doc. It is going to scan this JSON provided and create/update indexes. So i need a mechanism to convert my input log files to JSON??
2) Elastic search would scan this input document and create/update inverted indexes. These inverted indexes actually point to the exact document. So does that mean, ES would store these documents somewhere?? Would it store them as JSON docs? Is it purely in memory or on file sytem/database?
3) No when user searches for a keyword , ES returns back the document which contains the searched keyword. Now do i need to have the ability to convert back this JSON doc to the original log document that user expects??
Clearly im missing something.. Sorry for asking questions this silly , but im trying to improve my skills and its WIP.
Also , i understand that there is ELK stack out there. For some reasons we just want to use ES and not the LogStash and Kibana part of the stack..
Thanks
Logs needs to be parsed to JSON before they can be inserted into Elasticsearch
All documents are stored on the filesystem and some data is kept in memory but all data is persistent.
When you search Elasticsearch you get back matching JSON documents. If you want to display the original error message, you can store that original message in one of the JSON fields and display just that.
So if you just want to store log messages and not break them into fields or anything, you can simply take each row and send it to Elasticsearch like so:
{ "message": "This is my log message" }
To parse logs, break them into fields and add some logic, you will need to use some sort of app, like Logstash for example.
I started looking into ElasticSearch, and most examples of creating and reading involve POSTing data to the ElasticSearch server and then doing a GET to retrieve them.
Is this data that is POSTed stored separately by the ElasticSearch server? So, if I want to use ElasticSearch with MongoDB, does the raw data, not including the search indices, get stored twice (once copy for MongoDB and one for ElasticSearch)?
In conjunction with an answer to this question, a description or a link to a description of how ElasticSearch and the primary data store interact would be very helpful.
Yes, ElasticSearch can only search within its own data store, so a separate copy will be there.
You can use the mongodb connector to keep the data in elastic in sync with the mongo database: https://github.com/mongodb-labs/mongo-connector
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