Book Image

Elasticsearch 7.0 Cookbook - Fourth Edition

By : Alberto Paro
Book Image

Elasticsearch 7.0 Cookbook - Fourth Edition

By: Alberto Paro

Overview of this book

Elasticsearch is a Lucene-based distributed search server that allows users to index and search unstructured content with petabytes of data. With this book, you'll be guided through comprehensive recipes on what's new in Elasticsearch 7, and see how to create and run complex queries and analytics. Packed with recipes on performing index mapping, aggregation, and scripting using Elasticsearch, this fourth edition of Elasticsearch Cookbook will get you acquainted with numerous solutions and quick techniques for performing both every day and uncommon tasks such as deploying Elasticsearch nodes, integrating other tools to Elasticsearch, and creating different visualizations. You will install Kibana to monitor a cluster and also extend it using a variety of plugins. Finally, you will integrate your Java, Scala, Python, and big data applications such as Apache Spark and Pig with Elasticsearch, and create efficient data applications powered by enhanced functionalities and custom plugins. By the end of this book, you will have gained in-depth knowledge of implementing Elasticsearch architecture, and you'll be able to manage, search, and store data efficiently and effectively using Elasticsearch.
Table of Contents (23 chapters)
Title Page

Managing Clusters

In the Elasticsearch ecosystem, it's important to monitor nodes and clusters in order to manage and improve their performance and state. There are several issues that can arise at the cluster level, such as the following:

  • Node overheads: Some nodes can have too many shards allocated and become a bottleneck for the entire cluster.
  • Node shutdown: This can happen due to a number of reasons, for example, full disks, hardware failures, and power problems.
  • Shard relocation problems or corruptions: Some shards can't get an online status.
  • Shards that are too large: If a shard is too big, then the index performance decreases due to the merging of massive Lucene segments.
  • Empty indices and shards: These waste memory and resources; however, because each shard has a lot of active threads, if there are a large number of unused indices and shards, then...