Index lifecycle management in Elasticsearch - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Index Lifecycle Management (ILM) in Elasticsearch?

ILM is a feature in Elasticsearch that automates the management of index lifecycles, such as creation, rollover, and deletion, based on defined policies to optimize storage and performance.

beginner

Name the typical phases in an Elasticsearch ILM policy.

The typical ILM phases are: hot (indexing and searching), warm (less frequent access, optimized for cost), cold (rarely accessed, low cost), and delete (removes old data).

intermediate

What is the purpose of the 'rollover' action in ILM?

The rollover action creates a new index when the current index reaches a size, age, or document count threshold, helping to keep indexes manageable and performant.

intermediate

How does ILM help with storage cost optimization?

ILM moves older indexes to less expensive hardware or storage tiers during the warm and cold phases, reducing storage costs while keeping data accessible if needed.

beginner

What happens during the 'delete' phase in an ILM policy?

During the delete phase, Elasticsearch automatically deletes indexes that are no longer needed, freeing up storage space and keeping the cluster clean.

Which ILM phase is primarily used for active indexing and searching?

A delete

B hot

C cold

D warm

The hot phase is where active indexing and searching happen.

What does the rollover action in ILM do?

A Deletes old indexes

B Moves indexes to cold storage

C Creates a new index when thresholds are met

D Optimizes index shards

Rollover creates a new index when size, age, or document count limits are reached.

In which ILM phase are indexes moved to less expensive storage but remain searchable?

A warm

B delete

C hot

D indexing

The warm phase moves indexes to cheaper storage while keeping them searchable.

What is the main goal of the delete phase in ILM?

A Free up storage by removing old indexes

B Improve search speed

C Create new indexes

D Move data to hot storage

The delete phase removes old indexes to free storage space.

Which of the following is NOT a typical ILM phase?

A cold

B warm

C hot

D freeze

Freeze is not a standard ILM phase; the main phases are hot, warm, cold, and delete.

Explain the purpose and benefits of using Index Lifecycle Management in Elasticsearch.

Think about how ILM helps manage data as it ages.

Describe the rollover action and when it is triggered in an ILM policy.

Consider what happens when an index gets too big or old.