packtpublishing/mastering-elasticsearch-5.x-third-edition

Code repository for Mastering Elasticsearch 5.x Third Edition, published by Packt

Mastering Elasticsearch 5.x - Third Edition

This is the code repository for Mastering Elasticsearch 5.x - Third Edition, published by Packt. It contains all the supporting project files necessary to work through the book from start to finish.

About the Book

This book will give you a brief recap of the basics and also introduce you to the new features of Elasticsearch 5. We will guide you through the intermediate and advanced functionalities of Elasticsearch, such as querying, indexing, searching, and modifying data. We’ll also explore advanced concepts, including aggregation, index control, sharding, replication, and clustering. ##Instructions and Navigation All of the code is organized into folders. Each folder starts with a number followed by the application name. For example, Chapter02.

Chapters 1 and 8 do not have downloadable code or support files They contain simple commands

The code will look like the following:

public class CustomRestActionPlugin extends Plugin implements ActionPlugin
{
 @Override
 public List<Class<? extends RestHandler>> getRestHandlers() {
 return Collections.singletonList(CustomRestAction.class);
 }
}

This book was written using Elasticsearch 5.0.x, and all the examples and functions should work with it. In addition to that, you'll need a command-line tool that allows you to send HTTP requests such as curl, which are available for most operating systems. Please note that all examples in this book use the mentioned curl tool. If you want to use another tool, please remember to format the request in an appropriate way that is understood by the tool of your choice. In addition to that, to run examples in Chapter 11, Developing Elasticsearch Plugins, you will need a Java Development Kit (JDK) Version 1.8.0_73 and above installed and an editor that will allow you to develop your code (or a Java IDE such as Eclipse). To build the code and manage dependencies in Chapter 11, Developing Elasticsearch Plugins, we are using Apache Maven. The last chapter of this book has been written using Elastic Stack 5.0.0, so you will need to have Logstash, Kibana, and Metricbeat, all comprising the same version.

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mastering-elasticsearch-5.x-third-edition's Issues

Implementing a document read counter by user using painless

@packtprasadr
I came across your repo while searching for painless examples. As you know, the documentation and examples on elastic's own site are few and far between.

As per this forum post some months ago, I had been trying to solve this with painless, but had no joy in solving. I wonder if you would have some sense for how this could be accomplished with painless. It might make a good example for one of your chapters!

I'll regenerate the initial description from the forum thread here:

I have a document with a nested 'views' field, containing a 'user' and a 'count' value.

"views": 
[{"count": 2,
"user": "tt99"},
{"count":1,
"user: "tt88"}]

I'm trying to figure out a 'painless' script that, depending on the supplied parameters, either:
(a) adds the field "views", along with a user and default count of 1, when the field does not pre-exist;
(b) where the field does pre-exist, it appends the new user and a default count of 1 to the views array; or
(c) where both the field and user pre-exist, it just increments the counter by one, but doesn't duplicate the user.

I have tried this (which I know doesn't handle the field not pre-existing):

POST index/type/12345/_update
{
"script": {
"lang": "painless",
"inline": "if (ctx.source.views.user === params.view.user) {ctx.source.views.count += params.view.count} else {ctx._source.views += params.view}",
"params": {
"view": {"user":"tt99", "count":1}
}
}
}

However, it doesn't like how I am reference user: "Illegal list shortcut value [user]."

In the case above, I would expect, as my result, the count to increment to 3. If my params were {"user":"tt77", "count":1}, I would expect a new user "tt77" with count of 1 to get appended to the views array.

Should I be somehow looping through the json docs within the views array? I have seen a groovy example referencing a 'containskey' function .. but I tried that in 'painless' without any joy. You can see the thread for a few other approaches I took, but none appear to work. I would be curious if have an alternative approach that might work.

Thanks.