27,59 €
The Elastic Stack is a powerful combination of tools for distributed search, analytics, logging, and visualization of data from medium to massive data sets. The newly released Elastic Stack 6.0 brings new features and capabilities that empower users to find unique, actionable insights through these techniques. This book will give you a fundamental understanding of what the stack is all about, and how to use it efficiently to build powerful real-time data processing applications.
After a quick overview of the newly introduced features in Elastic Stack 6.0, you’ll learn how to set up the stack by installing the tools, and see their basic configurations. Then it shows you how to use Elasticsearch for distributed searching and analytics, along with Logstash for logging, and Kibana for data visualization. It also demonstrates the creation of custom plugins using Kibana and Beats. You’ll find out about Elastic X-Pack, a useful extension for effective security and monitoring. We also provide useful tips on how to use the Elastic Cloud and deploy the Elastic Stack in production environments.
On completing this book, you’ll have a solid foundational knowledge of the basic Elastic Stack functionalities. You’ll also have a good understanding of the role of each component in the stack to solve different data processing problems.
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First published: December 2017
Production reference: 1201217
ISBN 978-1-78728-186-8
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Authors
Pranav Shukla
Sharath Kumar M N
Copy Editors
Safis Editing
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Reviewer
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Technical Editor
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Elasticsearch is a trademark of Elasticsearch BV, registered in the U.S. and in other countries. Kibana is a trademark of Elasticsearch BV, registered in the U.S. and in other countries. Logstash is a trademark of Elasticsearch BV, registered in the U.S. and in other countries. Packetbeat is a trademark of Elasticsearch BV, registered in the U.S. and in other countries. Elastic is a trademark of Elasticsearch BV or Elastic Cloud is a trademark of Elasticsearch BV or Elastic Cloud Enterprise is a trademark of Elasticsearch BV or X-Pack is a trademark of Elasticsearch BV or Beats is a trademark of Elasticsearch BV or Winlogbeat is a trademark of Elasticsearch BV or Libbeat is a trademark of Elasticsearch BV or Metricbeat is a trademark of Elasticsearch BV or Filebeat is a trademark of Elasticsearch BV or Topbeat is a trademark of Elasticsearch BV or Heartbeat is a trademark of Elasticsearch BV.
Pranav Shukla is the founder and CEO of Valens DataLabs, a technologist, husband, and father of two. He is a big data architect and software craftsman who uses JVM-based languages. Pranav has diverse experience of over 14 years in architecting enterprise applications for Fortune 500 companies and start-ups. His core expertise lies in building JVM-based, scalable, reactive, and data-driven applications using Java/Scala, the Hadoop ecosystem, Apache Spark, and NoSQL databases. He is a big data engineering, analytics, and machine learning enthusiast.
Pranav founded Valens DataLabs with a vision to help companies leverage data to their competitive advantage. Valens DataLabs specializes in developing next-generation, cloud-based, reactive, and data-intensive applications using big data and web technologies. The company believes in agile practices, lean principles, test-driven and behavior-driven development, continuous integration, and continuous delivery for sustainable software systems.
In his free time, he enjoys reading books, playing musical instruments, singing, listening to music, and watching cricket. You can reach him via email at [email protected] and follow him on Twitter at @pranavshukla81.
Sharath Kumar M N has done his masters in Computer Science at The University of Texas, Dallas, USA. He has been in the IT industry for more than ten years now and is the Elasticsearch Solutions Architect at Oracle. He is an Elastic Stack advocate, and being an avid speaker he has also given several tech talks in conferences such as the Oracle Code Event. Sharath is a certified trainer—Elastic Certified Instructor—one of the few technology experts in the world who has been certified by Elastic Inc to deliver their official from the creators of Elastic training. He is also a data science and machine learning enthusiast.
In his free time, he enjoys trekking, listening to music, playing with his lovely pets Guddu and Milo and the geek in him loves exploring his Python skills for stock market analysis. You can reach him via email at [email protected].
Marcelo Ochoa works at the systems laboratory of Facultad de Ciencias Exactas, Universidad Nacional del Centro de la Provincia de Buenos Aires, Argentina. He is the CTO at www.scotas.com, a company that specializes in near-real-time search solutions using Apache Solr and Oracle. He divides his time between university jobs and external projects related to Oracle and big data technologies. He has worked on several Oracle-related projects, such as the translation of Oracle manuals and multimedia CBTs. His background is in database, network, web, and Java technologies. In the XML world, Marcelo is known as the developer of DB Generator for the Apache Cocoon project. He has worked on the open source projects DBPrism and DBPrism CMS, Lucene-Oracle integration using the Oracle JVM Directory implementation, and the Restlet.org project, where he worked on the Oracle XDB Restlet Adapter, an alternative to writing native REST web services inside a database-resident JVM.
Since 2006, he has been part of an Oracle ACE program and has recently linked to a Docker Mentor program.
Marcelo has coauthored Oracle Database Programming Using Java and Web Services by Digital Press and Professional XML Databases by Wrox Press. He has been a technical reviewer on several Packt books, such as Mastering Elastic Stack, Mastering Elasticsearch 5.x - Third Edition, Elasticsearch 5.x Cookbook - Third Edition, and so on.
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Preface
What this book covers
What you need for this book
Who this book is for
Conventions
Reader feedback
Customer support
Downloading the example code
Downloading the color images of this book
Errata
Piracy
Questions
Introducing Elastic Stack
What is Elasticsearch, and why use it?
Schemaless and document-oriented
Searching
Analytics
Rich client library support and the REST API
Easy to operate and easy to scale
Near real time
Lightning fast
Fault tolerant
Exploring the components of Elastic Stack
Elasticsearch
Logstash
Beats
Kibana
X-Pack
Security
Monitoring
Reporting
Alerting
Graph
Elastic Cloud
Use cases of Elastic Stack
Log and security analytics
Product search
Metrics analytics
Web search and website search
Downloading and installing
Installing Elasticsearch
Installing Kibana
Summary
Getting Started with Elasticsearch
Using the Kibana Console UI
Core concepts
Index
Type
Document
Node
Cluster
Shards and replicas
Mappings and data types
Data types
Core datatypes
Complex datatypes
Other datatypes
Mappings
Creating an index with the name catalog
Defining the mappings for the type of product
Inverted index
CRUD operations
Index API
Indexing a document by providing an ID
Indexing a document without providing an ID
Get API
Update API
Delete API
Creating indexes and taking control of mapping
Creating an index
Creating type mapping in an existing index
Updating a mapping
REST API overview
Common API conventions
Formatting the JSON response
Dealing with multiple indices
Searching all documents in one index
Searching all documents in multiple indexes
Searching all documents of a particular type in all indices
Summary
Searching-What is Relevant
Basics of text analysis
Understanding Elasticsearch analyzers
Character filters
Tokenizer
Standard Tokenizer
Token filters
Using built-in analyzers
Standard Analyzer
Implementing autocomplete with a custom analyzer
Searching from structured data
Range query
Range query on numeric types
Range query with score boosting
Range query on dates
Exists query
Term query
Searching from full text
Match query
Operator
minimum_should_match
Fuzziness
Match phrase query
Multi match query
Querying multiple fields with defaults
Boosting one or more fields
With types of multi match queries
Writing compound queries
Constant score query
Bool query
Combining OR conditions
Combining conditions AND and OR conditions
Adding NOT conditions
Summary
Analytics with Elasticsearch
The basics of aggregations
Bucket aggregations
Metric aggregations
Matrix aggregations
Pipeline aggregations
Preparing data for analysis
Understanding the structure of data
Loading the data using Logstash
Metric aggregations
Sum, average, min, and max aggregations
Sum aggregation
Average aggregation
Min aggregation
Max aggregation
Stats and extended stats aggregations
Stats aggregation
Extended stats Aggregation
Cardinality aggregation
Bucket aggregations
Bucketing on string data
Terms aggregation
Bucketing on numeric data
Histogram aggregation
Range aggregation
Aggregations on filtered data
Nesting aggregations
Bucketing on custom conditions
Filter aggregation
Filters aggregation
Bucketing on date/time data
Date Histogram aggregation
Creating buckets across time
Using a different time zone
Computing other metrics within sliced time intervals
Focusing on a specific day and changing intervals
Bucketing on geo-spatial data
Geo distance aggregation
GeoHash grid aggregation
Pipeline aggregations
Calculating the cumulative sum of usage over time
Summary
Analyzing Log Data
Log analysis challenges
Logstash
Installation and configuration
Prerequisites
Downloading and installing Logstash
Installing on Windows
Installing on Linux
Running Logstash
Logstash architecture
Overview of Logstash plugins
Installing or updating plugins
Input plugins
Output plugins
Filter plugins
Codec plugins
Exploring plugins
Exploring Input plugins
File
Beats
JDBC
IMAP
Output plugins
Elasticsearch
CSV
Kafka
PagerDuty
Codec plugins
JSON
Rubydebug
Multiline
Filter plugins
Ingest node
Defining a pipeline
Ingest APIs
Put pipeline API
Get Pipeline API
Delete pipeline API
Simulate pipeline API
Summary
Building Data Pipelines with Logstash
Parsing and enriching logs using Logstash
Filter plugins
CSV filter
Mutate filter
Grok filter
Date filter
Geoip filter
Useragent filter
Introducing Beats
Beats by Elastic.co
Filebeat
Metricbeat
Packetbeat
Heartbeat
Winlogbeat
Auditbeat
Community Beats
Logstash versus Beats
Filebeat
Downloading and installing Filebeat
Installing on Windows
Installing on Linux
Architecture
Configuring Filebeat
Filebeat prospectors
Filebeat global options
Filebeat general options
Output configuration
Filebeat modules
Summary
Visualizing data with Kibana
Downloading and installing Kibana
Installing on Windows
Installing on Linux
Configuring Kibana
Data preparation
Kibana UI
User interaction
Configuring the index pattern
Discover
Elasticsearch query string
Elasticsearch DSL query
Visualize
Kibana aggregations
Bucket aggregations
Metric
Creating a visualization
Visualization types
Line, area, and bar charts
Data table
MarkDown widget
Metric
Goal
Gauge
Pie charts
Co-ordinate maps
Region maps
Tag cloud
Visualizations in action
Response codes over time
Top 10 URLs requested
Bandwidth usage of top five countries over time
Web traffic originating from different countries
Most used user agent
Dashboards
Creating a dashboard
Saving the dashboard
Cloning the dashboard
Sharing the dashboard
Timelion
Timelion UI
Timelion expressions
Using plugins
Installing plugins
Removing plugins
Summary
Elastic X-Pack
Installing X-Pack
Installing X-Pack on Elasticsearch
Installing X-Pack on Kibana
Uninstalling X-Pack
Configuring X-Pack
Security
User authentication
User authorization
Security in action
New user creation
Deleting a user
Changing the password
New role creation
How to Delete/Edit a role
Document-level security or field-level security
X-Pack security APIs
User management APIs
Role management APIs
Monitoring Elasticsearch
Monitoring UI
Elasticsearch metrics
Overview tab
Nodes tab
The Indices tab
Alerting
Anatomy of a watch
Alerting in action
Create a new alert
Threshold Alert
Advanced Watch
How to Delete/Deactivate/Edit a Watch
Summary
Running Elastic Stack in Production
Hosting Elastic Stack on a managed cloud
Getting up and running on Elastic Cloud
Using Kibana
Overriding configuration
Recovering from a snapshot
Hosting Elastic Stack on your own
Selecting hardware
Selecting an operating system
Configuring Elasticsearch nodes
JVM heap size
Disable swapping
File descriptors
Thread pools and garbage collector
Managing and monitoring Elasticsearch
Running in Docker containers
Special considerations while deploying to a cloud
Choosing instance type
Changing default ports; do not expose ports!
Proxy requests
Binding HTTP to local addresses
Installing EC2 discovery plugin
Installing S3 repository plugin
Setting up periodic snapshots
Backing up and restoring
Setting up a repository for snapshots
Shared filesystem
Cloud or distributed filesystems
Taking snapshots
Restoring a specific snapshot
Setting up index aliases
Understanding index aliases
How index aliases can help
Setting up index templates
Defining an index template
Creating indexes on the fly
Modeling time series data
Scaling the index with unpredictable volume over time
Unit of parallelism in Elasticsearch
The effect of the number of shards on the relevance score
The effect of the number of shards on the accuracy of aggregations
Changing the mapping over time
New fields get added
Existing fields get removed
Automatically deleting older documents
How index-per-timeframe solves these issues
Scaling with index-per-timeframe
Changing the mapping over time
Automatically deleting older documents
Summary
Building a Sensor Data Analytics Application
Introduction to the application
Understanding the sensor-generated data
Understanding the sensor metadata
Understanding the final stored data
Modeling data in Elasticsearch
Defining an index template
Understanding the mapping
Setting up the metadata database
Building the Logstash data pipeline
Accept JSON requests over the web
Enrich the JSON with the metadata we have in the MySQL database
The jdbc_streaming plugin
The mutate plugin
Move the looked-up fields that are under lookupResult directly in JSON
Combine the latitude and longitude fields under lookupResult as a location field
Remove the unnecessary fields
Store the resulting documents in Elasticsearch
Sending data to Logstash over HTTP
Visualizing the data in Kibana
Set up an index pattern in Kibana
Build visualizations
How does the average temperature change over time?
How does the average humidity change over time?
How do temperature and humidity change at each location over time?
Can I visualize temperature and humidity over a map?
How are the sensors distributed across departments?
Create a dashboard
Summary
Monitoring Server Infrastructure
Metricbeat
Downloading and installing Metricbeat
Installing on Windows
Installing on Linux
Architecture
Event structure
Configuring Metricbeat
Module configuration
Enabling module configs in the modules.d directory
Enabling module config in the metricbeat.yml file
General settings
Output configuration
Logging
Capturing system metrics
Running Metricbeat with the system module
Specifying aliases
Visualizing system metrics using Kibana
Deployment architecture
Summary
Elastic Stack is a powerful combination of tools for the distributed search, analytics, logging, and visualization of data from medium to massive data sets. The newly released Elastic Stack 6.0 brings new features and capabilities that empower users to find unique, actionable insights through these techniques. This book will give you a fundamental understanding of what the stack is all about, and how to use it efficiently to build powerful real-time data processing applications. After a quick overview of the newly introduced features in Elastic Stack 6.0, you'll learn how to set up the stack by installing the tools, and see their basic configurations. Then the book shows you how to use Elasticsearch for distributed searching and analytics, along with Logstash for logging, and Kibana for data visualization. It also demonstrates the creation of custom plugins using Kibana and Beats. You'll find out about Elastic X-Pack, a useful extension for effective security and monitoring. We also provide useful tips on how to use the Elastic Cloud and deploy Elastic Stack in production environments.
Chapter 1, Introducing Elastic Stack, motivates the reader by introducing the core components of Elastic Stack, importance of distributed, scalable search and analytics that Elastic Stack offers with use cases of ElasticSearch. The chapter gives a brief introduction to all core components, shows where do they fit in the overall stack, and details the purpose of each component. It concludes with instructions for downloading and installing ElasticSearch and Kibana to get started.
Chapter 2, Getting Started with ElasticSearch, introduces the core concepts involved in ElasticSearch, which forms the backbone of the Elastic Stack. Concepts such as indexes, types, nodes, and clusters are introduced. The reader is introduced to the REST API for performing essential operations, datatypes, and mappings.
Chapter 3, Searching What Is Relevant, focuses on the search use-case for ElasticSearch. It introduces the concepts of text analysis, tokenizers, analyzers, and the need for analysis and relevance-based searching. The chapter uses and example use-case to cover the relevance based search topics.
Chapter 4, Analytics with ElasticSearch, covers various types of aggregations with examples to gain fundamental understanding. It starts off with very simple to complex aggregations to get powerful insights from terabytes of data. The chapter also covers reasons for using different types of aggregations.
Chapter 5, Analyzing Log Data, lays the foundation for the motivation behind logstash, the architecture of logstash, and installing and configuring logstash to set up basic data pipelines. Elastic 5 introduced Ingest Node, which can be used instead of a dedicated Logstash setup. We will also cover building pipelines using Elastic Ingest Nodes.
Chapter 6, Building Data Pipelines with Logstash, builds on the fundamental knowledge of Logstash by transformations and aggregation related filters. It covers how a rich set of filters brings Logstash closer to the other real-time and near-real-time stream processing frameworks with zero coding. It introduces the Beats platform, and the FileBeat component, which is used to transport log files from the edge machines.
Chapter 7, Visualizing Data with Kibana, covers how to effectively use Kibana to build beautiful dashboards for effective storytelling about your data. It uses a sample dataset and provides step-by-step guidance on creating visualizations in a few clicks.
Chapter 8, Elastic X-Pack, since we have covered ElasticSearch and the core components that help us build data pipelines and visualize data, it's now time to add the extensions needed for specific use cases. This chapter shows you how to install and configure X-Pack components in Elastic Stack and teaches you to secure, monitor, and use alerting extensions.
Chapter 9, Building a Sensor Data Analytics Application, puts together a complete application for sensor data analytics with the concepts learned so far. It shows you how to model your data in ElasticSearch, how to build the data-pipeline to ingest the data and how to visualize it using Kibana. The chapter also demonstrates how to effectively use X-Pack components to secure and monitor your pipeline, and get alerts when certain conditions are met.
Chapter 10, Running Elastic Stack in Production, covers recommendations on how to deploy Elastic Stack to production. It provides recommendations for taking your application to production and guidelines on typical configurations that need to be looked at for different use cases. It also covers deploying into cloud-based hosted providers such as Elastic Cloud.
Chapter 11, Monitoring Server Infrastructure, shows how we can use Elastic Stack to set up a real-time monitoring solution for your servers, applications that are built completely using Elastic Stack. It introduces another component of the Beats platform, MetricBeat, which is used to monitor servers/applications.
This book will guide you through the installation of all the tools that you need to follow the examples and download the following files with the version:
Elasticsearch 6.0
Kibana 6.0
This book is for data professionals who want to get amazing insights and business metrics from their data sources. If you want to get a fundamental understanding of Elastic Stack for the distributed, real-time processing of data, this book will help you. A fundamental knowledge of JSON would be useful, but is not mandatory. No previous experience with Elastic Stack is required.
In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning. Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "The next lines of code read the link and assign it to the BeautifulSoupfunction." A block of code is set as follows:
#import packages into the project from bs4 import BeautifulSoup from urllib.request import urlopen import pandas as pd
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
[default] exten => s,1,Dial(Zap/1|30) exten => s,2,
Voicemail
(u100) exten => s,
102
,Voicemail(b100) exten => i,1,Voicemail(
s0
)
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C:\Python34\Scripts> pip install -upgrade pip
C:\Python34\Scripts> pip install pandas
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We are living in an advanced stage of the information age. The emergence of the web, mobiles, social networks, blogs, and photo sharing has created a massive amount of data in recent years. These new data sources create information that cannot be handled using traditional data storage technology, typically relational databases. As an application developer or business intelligence developer, your job is to fulfill the search and analytics needs of the application.
A number of big data scale data stores have emerged in the last few years. This includes Hadoop ecosystem projects, several NoSQL databases, and search and analytics engines such as Elasticsearch. Hadoop and each NoSQL database have their own strengths and use cases.
Elastic Stack is a rich ecosystem of components serving as a full search and analytics stack. The main components of Elastic Stack are Kibana, Logstash, Beats, X-Pack, and Elasticsearch. Elasticsearch is at the heart of Elastic Stack, providing storage, search, and analytics capabilities. Kibana, which is also called a window into Elastic Stack, is a great visualization and user interface for Elastic Stack. Logstash and Beats help in getting the data into Elastic Stack. X-Pack provides powerful features including monitoring, alerting, and security to make your system production ready. Since Elasticsearch is at the heart of Elastic Stack, we will cover the stack inside-out, starting from the heart and moving on to the surrounding components.
In this chapter, we will cover the following topics:
What is Elasticsearch, and why use it?
A brief history of Elasticsearch and Apache Lucene
Elastic Stack components
Use cases of Elastic Stack
We will look at what Elasticsearch is and why you should consider it as your data store. Once you know the key strengths of Elasticsearch, we will look at the history of Elasticsearch and its underlying technology, Apache Lucene. We will then look at some use cases of Elastic Stack, and we will provide an overview of the Elastic Stack components.
Since you are reading this book, you probably already know what Elasticsearch is. For the sake of completeness, let us define Elasticsearch.
Elasticsearch is at the core of Elastic Stack, playing the central role of a search and analytics engine. Elasticsearch is built on a radically different technology, Apache Lucene. This fundamentally different technology in Elasticsearch sets it apart from traditional relational databases and other NoSQL solutions. Let us look at the key benefits of using Elasticsearch as your data store:
Schemaless, document-oriented
Searching
Analytics
Rich client library support and the REST API
Easy to operate and easy to scale
Near real time
Lightning fast
Fault tolerant
Let us look at each benefit one by one.
Elasticsearch does not impose a strict structure on your data; you can store any JSON documents. JSON documents are first class citizens in Elasticsearch as opposed to rows and columns in a relational database. A document is roughly equivalent to a record in a relational database table. Traditional relational databases require a schema to be defined beforehand to specify a fixed set of columns and their datatypes and sizes. Often the nature of data is very dynamic, requiring support for new or dynamic columns. The JSON documents naturally support this type of data. For example, take a look at the following document:
{ "name": "John Smith", "address": "121 John Street, NY, 10010", "age": 40 }
This document may represent a customer's record. Here the record has the name, address, and age of the customer. Another record may look like the following one:
{ "name": "John Doe", "age": 38, "email": "[email protected]" }
Note that the second customer doesn't have the address field, but instead has an email address. In fact, other customer documents may have completely different sets of fields. This provides a tremendous amount of flexibility in terms of what can be stored.
The core strength of Elasticsearch lies in its text processing capabilities. Elasticsearch is great at searching, especially a full-text search. Let us understand what a full-text search is.
When you want to perform a search similar to Google search on your own data, Elasticsearch is your best bet. You can index emails, text documents, PDF files, web pages, or practically any unstructured text documents and search across all your documents with search terms.
At a high level, Elasticsearch breaks up text data into terms and makes every term searchable by building Lucene indexes. You can build your own Google-like search for your application which is very fast and flexible.
In addition to supporting text data, Elasticsearch also supports other data types such as numbers, dates, geolocations, IP addresses, and many more. We will take an in-depth look at search in Chapter 3, Searching-What is Relevant.
Apart from search, the second most important functional strength of Elasticsearch is analytics. Yes, what was originally known just as a full-text search engine is now used as an analytics engine in a variety of use cases. Many organizations are running analytics solutions powered by Elasticsearch in production.
Search is like zooming in and finding a needle in a haystack. Search helps zoom in on precisely what is needed in huge amounts of data. Analytics is exactly the opposite of search; it is about zooming out and taking a look at the bigger picture. For example, you may want to know how many visitors on your website are from the United States as opposed to every other country, or you may want to know how many of your websites visitors use macOS, Windows, or Linux.
Elasticsearch supports a wide variety of aggregations for analytics. Elasticsearch aggregations are quite powerful and can be applied to various datatypes. We will take a look at the analytics capabilities of Elasticsearch in Chapter 4, Analytics with Elasticsearch.
Elasticsearch has very rich client library support to make it accessible by many programming languages. There are client libraries available for Java, C#, Python, JavaScript, PHP, Perl, Ruby, and many more. Apart from the official client libraries, there are community driven libraries for 20 plus programming languages.
Additionally, it has a very rich REST (Representational State Transfer) API which works on an HTTP protocol. The REST API is very well documented and quite comprehensive, making all operations available over HTTP.
All this means that Elasticsearch is very easy to integrate in any application to fulfill your search and analytics needs.
Elasticsearch can run on a single node and easily scale out to hundreds of nodes. It is very easy to start a single node instance of Elasticsearch; it works out of the box without any configuration changes and scales to hundreds of nodes.
Unlike most traditional databases which only allow vertical scaling, Elasticsearch can be scaled horizontally. It can run on tens or hundreds of commodity nodes instead of one extremely expensive server. Adding a node to an existing Elasticsearch cluster is as easy as starting up a new node in the same network, with virtually no extra configuration. The client application doesn't need to change, whether it is running against a single node or a hundred node cluster.
Data is available for querying typically within a second after it has been indexed (saved). Not all big data storage systems are real-time capable. Elasticsearch allows you to index thousands to hundreds of thousands of documents per second and makes them available for searching almost immediately.
Elasticsearch uses Apache Lucene as its underlying technology.By default, Elasticsearch indexes all the fields of your documents. This is extremely invaluable as you can query or search by any field in your records. You will never be in a situation in which you think if only I had chosen to create an index on this field. Elasticsearch contributors have leveraged Apache Lucene to its best advantage, and there are other optimizations which make it lightning fast.
Elasticsearch clusters can keep running even when there are hardware failures such as node failure and network failure. In the case of node failure, it replicates all the data that was on the failed node to another node in the cluster. In the case of network failure, Elasticsearch seamlessly elects master replicas to keep the cluster running. Whether it is node or network failure, you can rest assured that your data is safe.
Now that you know when and why Elasticsearch could be a great choice, let us take a high level view of the ecosystem—the Elastic Stack.
The Elastic Stack components are shown in the following figure. It is not necessary to include all of them in your solution. Some components are general purpose and they can be used outside of Elastic Stack without using any of the other components.
Let us look at the purpose of each component and how they fit in the stack:
Elasticsearch is at the heart of Elastic Stack. It stores all your data and provides search and analytic capabilities in a scalable way.We have already looked at the strengths of Elasticsearch and why you would want to use it. Elasticsearch can be used without using any other components to power your application in terms of search and analytics. We will cover Elasticsearch in great detail in Chapter 2, Getting Started with Elasticsearch, Chapter 3, Searching-What is Relevant, and Chapter 4, Analytics with Elasticsearch.
Logstash helps in centralizing event data such as logs,metrics, or any other data in any format. It can perform a number of transformations before sending it to a stash of your choice.It is a key component of Elastic Stack, used to centralize the collection and transformation processes in your data pipeline.
Logstash is a server side component. Its role is to centralize the collection of data from a wide number of input sourcesin a scalable way, and transform and send the data to an output of your choice. Typically, the output is sent to Elasticsearch, but Logstash is capable of sending it to a wide variety of outputs. Logstash has a plugin-based, extensible architecture. It supports three types of plugin: input plugins, filter plugins, and output plugins. Logstash has a collection of 200 plus supported plugins and the count is ever increasing.
Logstash is an excellent general purpose data flow engine which helps in building real-time, scalable data pipelines.
Beats is a platform of open source lightweight data shippers. Its role is complementary to Logstash. Logstash is a server-side component, whereas Beats has a role on the client side. Beats consists of a core library, libbeat, which provides an API for shipping data from the source, configuring the input options, and implementing logging. Beats is installed on machines that are not part of server-side components such as Elasticsearch, Logstash, or Kibana. These agents reside on non-cluster nodes which may also be called edge nodes sometimes.
There are many Beat components that have already been built by the Elastic team and the open source community. The Elastic team has built Beats including, Packetbeat, Filebeat, Metricbeat, Winlogbeat, Audiobeat, and Heartbeat.
Filebeat is a single-purpose Beat built to ship log files from your servers to a centralized Logstash server or Elasticsearch server. Metricbeat is a server monitoring agent that periodically collects metrics from the operating systems and services running on your servers. There are already around 40 community Beats built for specific purposes such as monitoring Elasticsearch, Cassandra, the Apache web server, JVM performance, and so on. You can build your own beat using libbeat if you don't find one that fits your needs.
We will take a deep dive into Logstash and Beats in Chapter 5, Analyzing Log Data and Chapter 6, Building Data Pipelines with Logstash.
Kibana is the visualization tool of Elastic Stack which can help you gain powerful insights about your data in Elasticsearch. It is often called a window into Elastic Stack. It offers many visualizations includinghistograms,maps, line charts, time series,and more. You can build visualizations with just a few clicks and interactively explore the data. It lets you build beautiful dashboards by combining different visualizations, sharing with others, and exporting high quality reports.
Kibana also has management and development tools. You can manage settings and configure X‑Pack security features for the Elastic Stack. Kibana also has development tools which enable developers to build and test REST API requests.
We will explore Kibana in Chapter 7, Visualizing Data with Kibana.
X-Pack adds essential features to make Elastic Stack production ready. It adds security, monitoring, alerting, reporting, and graph capabilities to Elastic Stack.
The security plugin within X-Pack adds authentication and authorization capabilities to Elasticsearch and Kibana so that only authorized people have access to the data, and they see only what they are allowed to see. The security plugin works across components seamlessly, securing access to Elasticsearch and Kibana.
The security extension also lets you configure fields and document level security with the licensed version.
You can monitor your Elastic Stack components so that there is no downtime. The monitoring component in X-Pack lets you monitor your Elasticsearch clusters and Kibana.
You can monitor clusters, nodes, and index level metrics. The monitoring plugin maintains a history of performance so that you can compare the current metrics with the past metrics. It also has a capacity planning feature.
The reporting plugin within X-Pack allows for generating printable, high-quality reports from Kibana visualizations. The reports can be scheduled to run periodically or on a per event basis.
X-Pack has sophisticated alerting capabilities that can alert you in multiple possible ways when certain conditions are met. It gives tremendous flexibility in terms of when, how, and who to alert.
You may be interested in detecting security breaches, such as when someone has five login failures within an hour from different locations, or when your product is trending on social media. You can use the full power of Elasticsearch queries to check when complex conditions are met.
Alerting provides a wide variety of options in terms of how alerts are sent. It can send alerts via email, Slack, Hipchat, and PagerDuty.
Graph lets you explore relationships in your data. The data in Elasticsearch is generally perceived as a flat list of entities without connections to other entities. This relationship opens up the possibility of new use cases. Graph can surface relationships among entities which share common properties such as people, places, products, or preferences.
Graph consists of Graph API and a UI within Kibana to let you explore this relationship. Under the hood, it leverages distributed querying, indexing at scale, and the relevance capabilities of Elasticsearch.
We will look at the some of X-Pack components in Chapter 8, Elastic X-Pack.
Elastic Cloud is the cloud-based, hosted, and managed setup of Elastic Stack components. The service is provided by the company Elastic (https://www.elastic.co/). Elastic is the company behind the development of Elasticsearch and other Elastic Stack components. All Elastic Stack components are open source except X-Pack (and Elastic Cloud). The company Elastic provides services for Elastic Stack components including training, development, support, and cloud hosting.
Apart from Elastic Cloud, there are other hosted solutions available for Elasticsearch including one from Amazon Web Services (AWS). The advantage of Elastic Cloud is that it is developed and maintained by the original creators of Elasticsearch and other Elastic Stack components.
Elastic Stack components have a variety of practical use cases, and new use cases are emerging as more plugins are added to existing components. As mentioned earlier, you may use a subset of the components for your use case. The following example use cases are by no means exhaustive, but are some of the most common ones:
Log and security analytics
Product search
Metrics analytics
Web search and website search
Let us look at each use case.
The Elasticsearch, Logstash, and Kibana trio was very popular as an ELK stack previously. The presence of Elasticsearch, Logstash, and Kibana (also known as ELK) makes Elastic Stack an excellent stack for aggregating and analyzing logs in a central place.
The application support teams face a great challenge administering and managing large numbers of applications deployed across tens or hundreds of servers. The application infrastructure could have the following components:
Web servers
Application servers
Database servers
Message brokers
Typically, enterprise applications have all or most of the types of servers which were explained earlier, and there are multiple instances of each server. In the event of an error or production issue, the support team has to log in to individual servers and look at the errors. It is quite inefficient to log in to individual servers and look at the raw log files. Elastic Stack provides a complete tool set to collect, centralize, analyze, visualize, alert, and report the errors as they occur. Here is how each component can be used to solve this problem:
The Beats framework, Filebeat in particular, can run as a lightweight agent to collect and forward the logs.
Logstash can centralize the events received from Beats, and parse and transform each log entry before sending it to the Elasticsearch cluster.
Elasticsearch indexes the logs. It enables both search and analytics on the parsed logs.
Kibana then lets you create visualizations based on errors, warnings, and other information logs. It lets you create dashboards where you can centrally monitor events as they occur, in real time.
With X-Pack, you can secure the solution, configure alerts, get reports, and analyze relationships in the data.
As you can see, you can get a complete log aggregation and monitoring solution using Elastic Stack.
A security analytics solution would be very similar to this; the logs and events being fed into the system would pertain to firewalls, switches, and other key network elements.