[sharathkanaka]

Description

Adds a page on restoring Alerting from a snapshot, for example, onto another cluster. With the 3.10 alerting and security changes below, monitors continue to run after their indexes are restored, and a REST admin can restore them.

• New page _observing-your-data/alerting/restore.md: which Alerting indexes to restore, the settings and roles to match on the new cluster first, the restore steps, restoring monitor sharing, and how document-level monitors continue after a restore.
• Alerting settings: the .opendistro-alerting-config row links to the new page.
• System indexes: adds .opensearch-alerting-finding* to the Alerting row and .opendistro-alerting-config-sharing to the Security plugin row.

Related code changes:

• Alerting: Reset stale last run context for doc-level monitors after restore alerting#2287 (doc-level monitors resume after restore), Use the current query index for doc-level monitors after restore alerting#2309 (missing query index), Register the findings indices as alerting system indices alerting#2310 (findings indexes are system indexes), Repair history write aliases after a snapshot restore alerting#2312 (history write aliases repaired after restore)
• Security: Allow REST admins to restore allowlisted system indices security#6557 (REST admins can restore listed system indexes), Allow restoring system indices by a pattern no broader than an allowlist entry security#6704 (patterns no broader than a list entry), Create a resource sharing index with its first sharing record instead of at node start security#6708 (sharing index created with the first sharing record), Add alerting sharing, findings and comments indices to the default restorable list security#6724 (Alerting sharing, findings and comments indexes in the default restore list)

Issues Resolved

N/A

Version

3.10

Frontend features

N/A

Checklist

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[sharathkanaka]

The general snapshot restore page (who can restore system indexes and the plugins.security.system_indices.restore.indices setting) comes in a follow-up PR. Step 1 links to that page.

[kolchfa-aws]

Thank you, @sharathkanaka! Doc review complete. I added the setting description, a verification step, rewrote for clarity, and reorganized the content so there's no duplication. Please review when you get a chance.