Briefly, this error occurs when you are using a feature or component in Elasticsearch that is marked as deprecated. This means that the feature or component is still functional in the current version, but it will be removed or replaced in future versions. To resolve this issue, you should identify the deprecated component and replace it with the recommended alternative. You can also check the Elasticsearch documentation or release notes for information about deprecated features and their replacements.
This guide will help you check for common problems that cause the log ” deprecation component started ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, deprecation.
Overview
Deprecation refers to processes and functions that are in the process of being eliminated and (possibly) replaced by newer ones.
Typically, a function will not disappear from one version to the next without warning. Normally this will happen across a number of versions. When you use a deprecated function in intermediate versions, it will continue to work as before, but you will receive warnings that the function in question is intended to disappear in the future.
How it works
There are a number of ways you can find out which functions have been deprecated, including: deprecation logs, reading the breaking pages documentation and paying attention to warnings.
In a deprecation log:
{"type": "deprecation", "timestamp": "2020-01-16T12:50:11,263+0000", "level": "WARN", "component": "o.e.d.r.a.d.RestDeleteAction", "cluster.name": "docker-cluster", "node.name": "es01", "cluster.uuid": "VGTYFgunQ_STTKVz6YHAGg", "node.id": "wh5J7TJ-RD-pJE4JOUjVpw", "message": "[types removal] Specifying types in document index requests is deprecated, use the typeless endpoints instead (/{index}/_doc/{id}, /{index}/_doc, or /{index}/_create/{id})." }Reading the breaking changes documentation for each version:
https://www.elastic.co/guide/en/elasticsearch/reference/7.5/breaking-changes-7.0.html
In kibana you may also see a warning if you run a deprecated command in the development panel:
#! Deprecation: [types removal] Specifying types in document index requests is deprecated, use the typeless endpoints instead (/{index}/_doc/{id}, /{index}/_doc, or /{index}/_create/{id}).It is important to act upon these warnings. Although your application still works, ignoring the warnings will almost certainly cause things to malfunction in a future upgrade.
Deprecation API
There is a depreciation API, which can help point you to deprecated functions on your cluster:
| Version 5.6-6.8 | GET /_xpack/migration/deprecations |
| Version 7 | GET /_migration/deprecations |
However, you should never depend on the deprecation API alone. Just because the API returns with no issues, it does not mean that everything in your setup will work out of the box when migrating! This is to be used in addition to looking through the deprecation log and breaking changes documentation.
Examples
- The removal of document types (“_type”) . Various document types were allowed in a single index in version 6, but this functionality has been removed. You will get warnings if you use document types in queries, and only 1 document type is allowed per index in version 7. The functionality is expected to be completely removed in version 8.
- The discovery.zen.minimum_master_nodes setting is permitted, but ignored, on 7.x nodes.
There are many more examples to be found in the breaking changes documentation.
Notes and good things to know
It is important to visit ALL the breaking changes for each minor version between the version you are using and the version you want to upgrade to.
https://www.elastic.co/guide/en/elasticsearch/reference/7.3/breaking-changes-7.3.html
Contains information that is not mentioned on the next page.
https://www.elastic.co/guide/en/elasticsearch/reference/7.5/breaking-changes-7.4.html
The best way is to go to the “breaking changes” page of the version you want to upgrade to, and then use the links to page look through all of the minor version pages down to the one you want to upgrade from, paying particular attention to the major version change (eg. 7.0 )
Opster supports all Elasticsearch versions so If you need help reach out
Log Context
Log “deprecation component started” classname is DeprecationIndexingComponent.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
}
}
@Override
protected void doStart() {
logger.info("deprecation component started");
this.appender.start();
Loggers.addAppender(LogManager.getLogger("org.elasticsearch.deprecation"); this.appender);
}
@Override
