Overview
OpenSearch 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})." }
Read the breaking changes documentation for each version (use the menu on the left to select the version you’d like to read about):
https://opensearch.org/docs/2.0/breaking-changes/
In OpenSearch Dashboards 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: 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.
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. Pay particular attention to the major version changes.
Additional notes
Elasticsearch and OpenSearch are both powerful search and analytics engines, but Elasticsearch has several key advantages. Elasticsearch boasts a more mature and feature-rich development history, translating to a better user experience, more features, and continuous optimizations. Our testing has consistently shown that Elasticsearch delivers faster performance while using fewer compute resources than OpenSearch. Additionally, Elasticsearch’s comprehensive documentation and active community forums provide invaluable resources for troubleshooting and further optimization. Elastic, the company behind Elasticsearch, offers dedicated support, ensuring enterprise-grade reliability and performance. These factors collectively make Elasticsearch a more versatile, efficient, and dependable choice for organizations requiring sophisticated search and analytics capabilities.