Elasticsearch Indexing电子书

Elasticsearch Indexing

Table of Contents

Elasticsearch Indexing

Credits

About the Author

About the Reviewer

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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

Errata

Piracy

Questions

1. Introduction to Efficient Indexing

Getting started

Understanding the document storage strategy

The _source field

The difference between the storable and searchable field

Analysis

Summary

2. What is an Elasticsearch Index

Nature of the Elasticsearch index

Indices

Mapping

Types

Document

Denormalization

Inverted index

Summary

3. Basic Concepts of Mapping

Basic concepts and definitions

Metadata fields

_source

_all

_timestamp

_ttl

Types

Object type

Root object type

Attachment type

The relationship between mapping and relevant search results

Understanding the schema-less

Summary

4. Analysis and Analyzers

Introducing analysis

Process of analysis

Built-in analyzers

Building blocks of Analyzer

Characte filters

HTML Strip Char filter

Pattern Replace Char filter

Tokenizer

Token filters

What's text normalization?

ICU analysis plugin

ASCII Foldng Token filter

An Analyzer Pipeline

Specifying the analyzer for a field in the mapping

Creating a custom analyzer

Summary

5. Anatomy of an Elasticsearch Cluster

Basic concepts

Node

Non-data nodes

Dedicated master nodes

Client nodes

Tribe node

Shards

Replicas

Explaining the architecture of distribution

Correctly configuring the cluster

Choosing the right amount of shards and replicas

Summary

6. Improving Indexing Performance

Configuration

Memory configuration

The ES_HEAP_SIZE environment variable

Avoiding swapping

Mlockall property

Garbage collector

The structure of JVM memory

What is the problem?

Monitoring garbage collection

VisualVM

Different strategies among garbage collectors

Process of deallocating memory

Types of garbage collector

Serial garbage collector

Parallel garbage collector

Concurrent Mark Sweep garbage collector

G1 garbage collector

Tuning the garbage collection

File descriptors

Increasing FD limit on Unix systems

Optimization of mapping definition

Norms

Feature index_option of string type

Exclude unnecessary fields

Extension of the automatic index refresh time

Segments and merging policies

Choosing the right merge policy

Tiered policy

log_byte_size policy

Log_doc policy

The optimize API

Store module

Store types

Simple filesystem store

New IO filesystem store

MMap filesystem store

Hybrid filesystem store

Throttling I/O operations

Throttling type

Bulk API

Bulk sizing

Notes

Summary

7. Snapshot and Restore

Snapshot repository

Repository types

Shared filesystem repository

URL repository

Cloud repository

HDFS filesystem repository

Snapshot

Restore

Overriding index settings during restore

How does the snapshot process works?

Summary

8. Improving the User Search Experience

Correction of users' spelling mistakes

Suggesters

Using the _suggest REST endpoint

Suggest object inclusion in the query

Term suggester

Configuring the term suggester

Common suggest options

Other and additional term suggester options

The phrase suggester

Configuring the phrase suggester

The completion suggester

Mapping the configuration for the completion suggester

Indexing on completion field

Get suggestions

Improving the relevancy of search results

Boosting the query

Bool query

Synonyms

Be careful about the _all field

Summary

Index