[Elasticsearch Beginners - notes] Elasticsearch functions, application scenarios and features introduced

Disclaimer: This article is a blogger original article, shall not be reproduced without the bloggers allowed. https://blog.csdn.net/mr_zhuqiang/article/details/88642210

Elasticsearch formally introduced

1. Elasticsearch function, doing
2. Elasticsearch of application scenarios, can play a role in any place
3. Elasticsearch characteristics with other similar things in different places where

Function, doing

1. Distributed search engine and data analysis engine

   Search: In Baidu, the site of the station search, retrieval of IT systems

   Data analysis: Electric's Web site, the last seven business days before this commodity toothpaste sales of the top 10 of what; news sites, one month before the recent visits rankings news section 3 of which are

   Distributed, search, data analysis

2. Full-text search, structured retrieval, data analysis

   Full Text Search: I would like to find the product name containing toothpaste goods,select * from products where product_name like "%牙膏%"

   Structured Search: I want to find a product classified as of supplies of goods which are,select * from products where category_id='日化用品'

   Partial matching, auto-complete, search for error correction, searching recommendation

   Data Analysis: We analyze the number of products available in each commodity classification,select category_id,count(*) from products group by category_id

3. Massive data in near real-time processing

   Distributed: ES huge amounts of data can be automatically distributed to multiple servers to store and retrieve up

   The sea of ​​data processing: distributed later, you can use a large number of servers to store and retrieve data, naturally handle huge amounts of data can be achieved

   Near real-time: retrieving data takes 1 hour (this is not a near real-time, off-line batch processing, batch-processing); data search and analysis at the second level

With distributed / mass data opposite: lucene, stand-alone applications, can only be used on a single server can only handle a single server can handle the amount of data

Applicable scene, can play a role in any place

foreign

1. Wikipedia, similar to Baidu Encyclopedia, toothpaste, toothpaste Wikipedia, full-text search, highlighting, search Recommended

2. The Guardian (foreign news sites)

   Similarly Sohu news, log user behavior (click, browse, favorites, comments) + social network data (related to certain views on the news), data analysis, to the author of each news article, let him know that his article public feedback (good, bad, hot, junk, contempt, worship)

3. Stack Overflow (abroad program exception discussion forum)

   IT problems, program error, submit up, someone will answer and discuss with you, full text search, search-related questions and answers, program error, it will paste the error message to go inside, there is no corresponding search of answers

4. GitHub (open source management), search of billions of rows of code

5. Electricity supplier site, search for a product

6. Log data analysis, logstash acquires log, ES complex data analysis (ELK technology, elasticsearch + logstash + kibana)

7. Commodity price monitoring website

   Users set the threshold price of a commodity, when below this threshold, a notification message is sent to the user, for example, subscribe to monitor toothpaste, Colgate toothpaste if the Family set below 50 dollars to notice me, I would buy

8. BI system, Business Intelligence, Business Intelligence.

   For example, there is a large shopping Group, BI, analyze the composition constitutes a certain amount of consumption of the users of regional trends last three years as well as user groups, output related to the number of reports, xxx area, the last three years, showing the amount of annual consumption 100% growth, and user groups 85% senior white-collar, open a new mall. ES perform data analysis and mining, Kibana data visualization

domestic

Site Search (electricity supplier, recruitment, portals, etc.), IT systems search (OA, CRM, ERP, etc.), data analysis (ES popular use of a scene)

Feature

1. It can be used as a large-scale distributed clusters (hundreds of servers) technology

   PB-level data processing, services large companies; you can also run on a single machine, a small service company

2. Elasticsearch not a new technology

   Mainly to full-text search, and distributed data analysis techniques, combined together, before the formation of a unique ES;

   lucene (full-text search), commercial data analysis software (is there), distributed database (mycat)

3. For users, it is out of the box

   Very simple, as small and medium sized applications directly deployed about three minutes ES, as the system can be used in a production environment, the amount of data, the operation is not too complicated

4. Database functionality in many areas of the face is not enough (the transaction, as well as a variety of online transaction type of operation)

   Special features, such as full-text search, a synonym, relevance ranking, complex data analysis, near-real-time processing of massive data; Elasticsearch as a complement to traditional database, the database provides a lot of features that are not can not provide

GIHUB：https://github.com/zq99299/note-book/blob/master/docs/elasticsearch-core/index.md