Index Management Glossary

This glossary provides definitions of key technical terms and concepts used throughout the Automated Index Management (AIM) documentation.

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Action: An operation performed on an index when a step’s conditions are met, such as closing, deleting, or changing allocation settings.
Age Condition: A condition that triggers based on how long ago an index was created or rolled over.
AIM: Automated Index Management - Search Guard’s feature for lifecycle management of indices.
Alias: An alternate name for one or more indices, used in rollover operations and index management.
Allocation Action: An action that changes where index shards are allocated within the cluster based on node attributes.

Close Action: An action that closes an index, making it unavailable for read or write operations while preserving data on disk.
Condition: A rule that determines when a step’s actions should be executed, based on index properties like age, size, or document count.

Delete Action: An action that permanently removes an index and all its data from the cluster.
Doc Count Condition: A condition that triggers based on the number of documents in an index.

Execution Delay: The time period AIM waits before evaluating policies after startup or configuration changes.

Force Merge Action: An action that merges index segments to reduce their number, improving search performance and reducing storage.

Index Count Condition: A condition that triggers when the number of indices associated with an alias exceeds a threshold.
Index Priority: A setting that determines the order in which indices are recovered after cluster restarts.
Instance: A specific index being managed by a policy, including its current state and step.

Managed Index: An index that has a policy assigned and is being monitored by AIM.

Policy: A complete lifecycle management configuration consisting of steps, conditions, and actions for managing indices.
Policy Instance: The association between a policy and a specific index, including execution state and history.
Priority Action: An action that sets the recovery priority for an index.

Read-Only Action: An action that makes an index read-only, preventing write operations while allowing reads.
Replica Count Action: An action that changes the number of replica shards for an index.
Rollover Action: An action that creates a new index and redirects writes when conditions are met, commonly used with time-series data.
Rollover Alias: An alias used in rollover operations that points to the active index for writes.

Segment: A Lucene index component; force merge reduces the number of segments to improve performance.
Set Priority Action: An action that configures the index recovery priority.
Set Read-Only Action: An action that changes an index to read-only mode.
Set Replica Count Action: An action that modifies the number of index replicas.
Size Condition: A condition that triggers based on the total storage size of an index.
Snapshot Action: An action that creates a backup snapshot of an index.
Step: A stage in a policy lifecycle containing conditions and actions to be executed.
State: The current execution status of a policy instance on an index.

Transition: The movement of an index from one policy step to another when conditions are met.

Write Index: In a rollover scenario, the index currently receiving write operations.