WIP: upgrade from 7.17 guide

deploy-manage/toc.yml

@@ -808,6 +808,7 @@ toc:
           - file: upgrade/prepare-to-upgrade/upgrade-assistant.md
       - file: upgrade/deployment-or-cluster.md
         children:
+          - file: upgrade/deployment-or-cluster/upgrade-717-eol.md
           - file: upgrade/deployment-or-cluster/upgrade-on-ech.md
           - file: upgrade/deployment-or-cluster/upgrade-on-ece.md
           - file: upgrade/deployment-or-cluster/upgrade-on-eck.md

deploy-manage/upgrade/deployment-or-cluster/upgrade-717-eol.md

@@ -0,0 +1,250 @@
+---
+applies_to:
+  stack: all
+  serverless: unavailable
+---
+# Upgrade from 7.17 to {{version.stack}}
+
+{{stack}} version 7.17 has a defined end of support date of 15 January 2026, as stated in the [Elastic Product & Version End of Life Policy](https://www.elastic.co/support/eol). This document provides a guided plan to upgrade from 7.17 to the latest {{version.stack}} release. It complements the official upgrade documentation by showing how the different pieces fit together in a complete upgrade exercise.  
+
+% to decide
+Wherever possible, this document links to the existing upgrade guides. In some cases, such as upgrades on {{ech}}, we provide more detailed, step-by-step instructions.
+
+The content applies to all deployment types ({{ech}} (ECH), {{ece}} (ECE), {{eck}} (ECK), and self-managed clusters). Use the tabs to follow the path for your deployment.
+
+## Overview
+
+Upgrading from 7.17 to {{version.stack}} requires two major upgrades. Each major upgrade must be prepared and executed independently, although the planning phase can be shared.
+
+1. **7.17.x → 8.19.x**  
+    This brings the cluster onto the latest supported 8.x release, which is the required intermediate version before upgrading to 9.x.
+    Before being able to run this upgrade, all ingest components and client libraries must be upgraded to 7.17.x.
+
+2. **8.19.x → {{version.stack}}**  
+    This completes the upgrade to the latest 9.x release.
+    Before being able to run this upgrade, all ingest components and client libraries must be upgraded to 8.19.x.
+
+The following sections describe these phases in detail and point to the relevant documentation for each deployment type.
+
+Refer to [upgrade paths](/deploy-manage/upgrade.md#upgrade-paths) for more information.
+
+(TBD: Consider [reindex to upgrade](https://www.elastic.co/docs/deploy-manage/upgrade/prepare-to-upgrade#reindex-to-upgrade)? as an alternative method to move directly to a new 9.x cluster? )
+
+## Upgrade planning
+
+The [planning phase](/deploy-manage/upgrade/plan-upgrade.md) ensures that the upgrade is well understood and can be executed with minimal risk.  
+It involves defining a clear sequence of actions and assessing the impact on [service availability](/deploy-manage/upgrade.md#availability-during-upgrades) and performance during the upgrade.
+
+For the 7.17.x → 9.x upgrade path, the main planning outcome is a set of required actions to ensure compatibility across the ecosystem:
+
+* **Ingest components:** Before upgrading to 8.19.x, ensure that all ingest components ({{beats}}, {{agent}}, {{ls}}, APM) are on version 7.17.x.  
+  Before the 8.19.x → {{version.stack}} upgrade, upgrade all ingest components to 8.19.x.  
+* **Client libraries:** If you rely on [{{es}} client libraries](/reference/elasticsearch-clients/index.md), make sure to include them in your plan.
+  Typically, libraries are upgraded to match the final version after the deployment upgrade.
+* **ECK:** {applies_to}`eck:` Upgrade ECK from 2.x to 3.x before moving to 9.x.  
+* **ECE:** {applies_to}`ece:` Upgrade ECE from 3.x to 4.x before moving to 9.x.  
+
+Finally, it is strongly recommended to [test the full upgrade process in a non-production environment](/deploy-manage/upgrade/plan-upgrade.md#test-in-a-non-production-environment) before applying it to production.
+
+(recommend to perform the entire list of compatibility checks in self-managed clusters?)
+
+### Planning result examples
+
+The following examples illustrate what a completed planning phase might look like for different deployment types. Each example describes the initial situation and outlines the overall upgrade plan.
+
+(TBD: maybe we remove all this section here and we just include it together with the execution steps)
+
+::::{applies-switch}
+
+:::{applies-item} ess:
+- Ensure all deployments are in 7.17.x (upgrade any older deployment to 7.17.latest)
+- Ensure all ingest components are in 7.17.x (upgrade any older component to 7.17.latest)
+- Run upgrade assistant to prepare the cluster for the major upgrade to 8.19.x
+- Upgrade deployments to latest 8.19.x
+- Upgrade all ingest components to 8.19.x
+- Run upgrade assistant to prepare the cluster for the major upgrade to 9.x
+- Upgrade deployments to {{version.stack}}
+- (optional) upgrade all ingest components to {{version.stack}}
+:::
+
+:::{applies-item} ece:
+- Ensure all deployments are in 7.17.x (upgrade any older cluster)
+- Ensure all ingest components are in 7.17.x (upgrade any older component)
+- If ECE runs on 3.x, upgrade ECE to latest 4.x release.
+
+- Upgrade deployments to latest 8.19.x
+- Upgrade all ingest components to 8.19.x
+
+- Upgrade deployments to {{version.stack}}
+- (optional) upgrade all ingest components to {{version.stack}}
+:::
+
+
+:::{applies-item} { eck: }
+- Ensure all clusters are in 7.17.x (upgrade any older cluster)
+- Ensure all ingest components are in 7.17.x (upgrade any older component)
+- If ECK runs on 2.x, upgrade ECK to latest 3.x release.
+
+- Run upgrade assistant to check if the cluster is ready for a major upgrade.
+- Upgrade clusters to latest 8.19.x
+- Upgrade all ingest components to 8.19.x
+- Run upgrade assistant to check if the cluster is ready for a major upgrade.
+- Upgrade clusters to latest 9.x
+- (optional) Upgrade all ingest components to 9.x
+:::
+
+:::{applies-item} self:
+- Ensure all deployments are in 7.17.x (upgrade any older cluster)
+- Ensure all ingest components are in 7.17.x (upgrade any older component)
+
+- Run upgrade assistant to check if the cluster is ready for a major upgrade.
+- Upgrade cluster to latest 8.19.x in the following order: {{es}}, {{kib}}, Fleet Server, and Elastic APM (if used)
+- Upgrade all ingest components to 8.19.x
+
+- Run upgrade assistant to check if the cluster is ready for a major upgrade.
+- Upgrade cluster to {{version.stack}} in the same order as before
+- (optional) upgrade all ingest components to {{version.stack}}
+:::
+
+::::
+
+## Upgrade Step 1: 7.17.x → 8.19.x
+
+draft items for preparations:
+- Assess deployment topology (clusters, nodes, orchestrator type)  
+- Inventory dependencies (plugins, custom ingest pipelines, clients, integrations)  
+- Run Upgrade Assistant and resolve issues  
+- Define snapshot/backup and rollback strategy  
+- Test upgrade steps in a staging environment  
+- Align with maintenance windows and SLAs  
+
+
+### Preparation
+
+* Index compatibility:  upgrade assistant.
+- Confirm prerequisites and compatibility  
+- Validate cluster health and shard allocation  
+- Review version-specific breaking changes (link to docs)  
+- Take snapshots / backups  
+
+### Execution
+- Upgrade process (tabs for {{ech}}, {{ece}}, {{eck}}, self-managed)  
+- Rolling vs full-cluster downtime options  
+- Client compatibility considerations  
+- Ingest components compatibility considerations.
+
+CCR / CCS / Remote clusters / ML / Transform indices implications?
+Monitoring clusters implications?
+
+### Validation
+- Post-upgrade health checks (cluster status, ingest, search)  
+- Validate monitoring dashboards and alerts  
+- Resolve deprecation warnings  
+
+## Upgrade Step 2: 8.19.x → {{version.stack}}
+
+### Preparation
+
+* Index compatibility:  upgrade assistant.
+- Repeat prerequisites and compatibility checks  
+- Review 9.x breaking changes  
+- Ensure clients are compatible (REST API compatibility mode, etc.)  
+- Take snapshots / backups  
+
+### Execution
+- Upgrade process (tabs for {{ech}}, {{ece}}, {{eck}}, self-managed)  
+- Node upgrade order and orchestration  
+- Upgrade ecosystem components (Beats, Logstash, Elastic Agent, APM, etc.)  
+
+CCR / CCS / Remote clusters / ML / Transform indices implications?
+Monitoring clusters implications?
+
+### Validation
+- Post-upgrade cluster validation  
+- Performance and stability checks  
+- Review and remove deprecated settings  
+
+## Post-Upgrade Wrap-Up
+- Confirm cluster stability over an observation period  
+- Update operational runbooks and monitoring baselines  
+- Validate client library upgrades and integrations  
+- Decommission old snapshots if no longer needed  
+- Document lessons learned  
+
+<!--
+
+-----
+older text and links in case of need
+
+{{stack}} version 7.17 is getting EOL soon. This document provides guidance to upgrade from 7.17 to the latest {{version.stack}} version, relying on existing documents and procedures.
+
+old reference: https://www.elastic.co/guide/en/elastic-stack/7.17/upgrading-elastic-stack.html
+https://www.elastic.co/guide/en/elastic-stack/8.18/upgrading-elastic-stack.html
+new: https://www.elastic.co/docs/deploy-manage/upgrade/deployment-or-cluster
+
+Upgrade 8.19: https://www.elastic.co/guide/en/elasticsearch/reference/8.19/setup-upgrade.html
+
+Prepare from 7.x: https://www.elastic.co/guide/en/elastic-stack/8.19/upgrading-elastic-stack.html#prepare-to-upgrade
+
+Elastic Cloud specifics? 
+ECE or ECK specifics?
+
+## Overview
+
+Upgrading from 7.17 to the latest {{version.stack}} implies two major upgrades. Each of them needs to be treated independently in terms preparations and execution. The planning phase can be common.
+
+* Upgrade from 7.17.x to 8.19.x
+
+* Upgrade from 8.19.x latest to {{version.stack}}
+
+As a general guideline we recommend reading the following documents before upgrading:
+- Plan your upgrade: This doc tells you all the necessary to plan your upgrade properly.
+
+- Preparations.
+
+Run upgrade assistant.
+
+Consider [reindex to upgrade](https://www.elastic.co/docs/deploy-manage/upgrade/prepare-to-upgrade#reindex-to-upgrade)? 
+
+## Different deployment types
+
+asda
+
+## Upgrade order and plan
+
+
+## Major upgrade to 8.19.x
+
+### Preparations and pre-requisites.
+CCR / CCS / Remote clusters / ML / Transform indices
+Execute the upgrade
+
+
+Run the upgrade assistant as explained in [this doc](https://www.elastic.co/guide/en/elastic-stack/8.19/upgrading-elastic-stack.html#prepare-to-upgrade).
+
+Notes:
+* If you use a monitoring cluster, upgrade the monitoring cluster first.
+* If you use remote clusters functionality, upgrade the remote clusters first.
+
+Divide the recommendations per deployment type: for Elastic Cloud we can tell that the UI takes care of almost everything, the user needs to take care of the external components (beats, Elastic Agent, Logstash, etc.)
+
+### Execute the upgrade
+
+Start with the deployment
+Don't forget beats and external components afterwards, as upgrading them to 8.19.x is a pre-requisite to upgrade to 9.x
+
+Self-managed: Follow the [official guide](8.19) to perform the rolling upgrade of your cluster.
+
+ECH: (we need to guide users or check the current doc).
+ECE: (we need to guide users or check the current doc).
+ECK: (check docs to run the upgrade)
+
+## Major upgrade to 9.1.x
+
+### Preparations and pre-requisites
+
+### Execute the upgrade
+
+(Optional): Upgrade external components to 9.x, although 8.19.x is compatible with 9.x.
+
+