OpenSearch/docs/reference/ilm/example-index-lifecycle-policy.asciidoc

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[[example-using-index-lifecycle-policy]]
=== Tutorial: Manage {filebeat} time-based indices
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<titleabbrev>Manage {filebeat} time-based indices</titleabbrev>
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With {ilm} ({ilm-init}), you can create policies that perform actions automatically 
on indices as they age and grow. {ilm-init} policies help you to manage
performance, resilience, and retention of your data during its lifecycle. This tutorial shows
you how to use {kib}’s *Index Lifecycle Policies* to modify and create {ilm-init}
policies. You can learn more about all of the actions, benefits, and lifecycle
phases in the <<overview-index-lifecycle-management, {ilm-init} overview>>.


[discrete]
[[example-using-index-lifecycle-policy-scenario]]
==== Scenario

You’re tasked with sending syslog files to an {es} cluster. This
log data has the following data retention guidelines:

* Keep logs on hot data nodes for 30 days
* Roll over to a new index if the size reaches 50GB
* After 30 days:
** Move the logs to warm data nodes
** Set <<glossary-replica-shard, replica shards>> to 1
** <<indices-forcemerge, Force merge>> multiple index segments to free up the space used by deleted documents
* Delete logs after 90 days


[discrete]
[[example-using-index-lifecycle-policy-prerequisites]]
==== Prerequisites

To complete this tutorial, you'll need:

* An {es} cluster with hot and warm nodes configured for shard allocation
awareness. 

** {ess}: 
Choose the Elastic Stack and then the {cloud}/ec-getting-started-profiles-hot-warm.html[hot-warm architecture] hardware profile.

** Self-managed cluster: 
Add node attributes as described for {ref}/shard-allocation-filtering.html[shard allocation filtering].
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For example, you can set this in your `elasticsearch.yml` for each data node:
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[source,yaml]
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node.attr.data: "warm"
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* A server with {filebeat} installed and configured to send logs to the `elasticsearch`
output as described in {filebeat-ref}/filebeat-getting-started.html[Getting Started with {filebeat}].

[discrete]
[[example-using-index-lifecycle-policy-view-fb-ilm-policy]]
==== View the {filebeat} {ilm-init} policy

{filebeat} includes a default {ilm-init} policy that enables rollover. {ilm-init}
is enabled automatically if you’re using the default `filebeat.yml` and index template.

To view the default policy in {kib}:

. Go to Management and select *Index Lifecycle Policies*.
. Search for _filebeat_
. Select the _filebeat-version_ policy.

This policy initiates the rollover action when the index size reaches 50GB or
becomes 30 days old.

[role="screenshot"]
image::images/ilm/tutorial-ilm-hotphaserollover-default.png["Default policy"]


[discrete]
==== Modify the policy

The default policy is enough to prevent the creation of many tiny daily indices.
You can modify the policy to meet more complex requirements.

. Activate the warm phase.
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image::images/ilm/tutorial-ilm-modify-default-warm-phase-rollover.png["Modify to add warm phase"]

.. Set one of the following options to control when the index moves to the warm phase:

*** Provide a value for *Timing for warm phase*. Setting this to *15* keeps the
indices on hot nodes for a range of  15-45 days, depending on when the initial
rollover occurred.

*** Enable *Move to warm phase on rollover*. The index might move to the warm phase
more quickly than intended if it reaches the *Maximum index size* before the
the *Maximum age*.

.. In the *Select a node attribute to control shard allocation* dropdown, select
*data:warm(2)* to migrate shards to warm data nodes.

.. Change *Number of replicas* to *1*.

.. Enable *Force merge data* and set *Number of segments* to *1*.

NOTE:  When rollover is enabled in the hot phase, action timing in the other phases
is based on the rollover date.
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. Activate the delete phase and set *Timing for delete phase* to *90* days.
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[role="screenshot"]
image::images/ilm/tutorial-ilm-delete-rollover.png["Add a delete phase"]

[discrete]
==== Create a custom policy

If meeting a specific retention time period is most important, you can create a
custom policy.  For this option, you use {filebeat} daily indices without
rollover.

To create a custom policy:

. Go to Management and select *Index Lifecycle Policies*.
. Click *Create policy*.
. Activate the warm phase and configure it as follows:
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**Timing for warm phase**: 30 days from index creation

**Node attribute**: `data:warm`

**Number of replicas**: 1

**Force merge data**: enable

**Number of segments**: 1

[role="screenshot"]
image::images/ilm/tutorial-ilm-custom-policy.png["Modify the custom policy to add a warm phase"]
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. Activate the delete phase and set the timing to 90 days.
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[role="screenshot"]
image::images/ilm/tutorial-ilm-delete-phase-creation.png["Delete phase"]

To configure the index to use the new policy:

. Go to Management and select *Index Lifecycle Policies*.
. Find your {ilm-init} policy and click its *Actions* link.
. Choose *Add policy to index template*.
. Select your {filebeat} index template name from the *Index template* list. For example, `filebeat-7.5.x`.
. Click *Add Policy* to save the changes.
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NOTE: If you initially used the default {filebeat} {ilm-init} policy, you will
see a notice that the template already has a policy associated with it. Confirm
that you want to overwrite that configuration.

When you change the policy associated with the index template, the active
index will continue to use the policy it was associated with at index creation
unless you manually update it. The next new index will use the updated policy.
For more reasons that your {ilm-init} policy changes might be delayed, see
<<update-lifecycle-policy, Update Lifecycle Policy>>.