Add reference to prefer-ilm setting for apm lifeycle known bug (#4501) (

#4515)

* Add reference to prefer-ilm setting for apm lifeycle known bug

* Refactor

* APM known issue correction

* Update docs/en/observability/apm/known-issues.asciidoc

Co-authored-by: Colleen McGinnis <[email protected]>

* clean up text

* Update docs/en/observability/apm/known-issues.asciidoc

Co-authored-by: Vishal Raj <[email protected]>

---------

Co-authored-by: Francesco Gualazzi <[email protected]>
Co-authored-by: Brandon Morelli <[email protected]>
Co-authored-by: Colleen McGinnis <[email protected]>
(cherry picked from commit c576b14)

Co-authored-by: Vishal Raj <[email protected]>

docs/en/observability/apm/known-issues.asciidoc

@@ -46,10 +46,11 @@ to `true` by following the {observability-guide}/apm-ilm-how-to.html[updated gui
 [discrete]
 == Upgrading to v8.15.x may cause ingestion to fail
 
-_Elastic Stack versions: 8.15.0+_
+_Elastic Stack versions: 8.15.0, 8.15.1, 8.15.2, 8.15.3_ +
+_Fixed in Elastic Stack version 8.15.4_
 
 // The conditions in which this issue occurs
-The issue only occurs when _upgrading_ the {stack} from 8.12.2 or lower directly to any 8.15.x version.
+The issue only occurs when _upgrading_ the {stack} from 8.12.2 or lower directly to any 8.15.x version prior to 8.15.4.
 The issue does _not_ occur when creating a _new_ cluster using any 8.15.x version, or when upgrading
 from 8.12.2 to 8.13.x or 8.14.x and then to 8.15.x.
 
@@ -106,63 +107,26 @@ stream lifecycle configuration, such existing data streams become unmanaged for
 lifecycle configurations.
 
 // How to fix it
-Upgrading to 8.15.1 should fix any new indices created for the data stream. However,
-indices created in version 8.15.0 would remain unmanaged if the default ILM policy is
-used. One of the following approaches can be adopted to fix the unmanaged indices:
-
-. Manually delete the indices when they are no longer needed.
-. Explicitly configure APM data streams with the default data stream lifecycle config.
-Using this approach would migrate all data streams to use data stream lifecycles,
-which should be equivalent to the default ILM policies:
+Upgrading to 8.15.1 resolves the lifecycle issue for any new indices created for APM data streams.
+However, indices created in version 8.15.0 will remain unmanaged if the default ILM policy is in place.
+To fix these unmanaged indices, consider one of the following approaches:
+
+. Manually delete the unmanaged indices when they are no longer needed.
+. Explicitly configure APM data streams to use the default data stream lifecycle configuration.
+This approach migrates all affected data streams to use data stream lifecycles,
+maintaining behavior equivalent to the default ILM policies.
+Apply this fix only to data streams that have unmanaged indices due to missing default ILM policies.
 +
 [source,txt]
 ----
-PUT _data_stream/traces-apm-*/_lifecycle
+PUT _data_stream/{{data_stream_name}}-{{data_stream_namespace}}/_lifecycle
 {
-  "data_retention": "10d"
-}
-
-PUT _data_stream/traces-apm.rum*/_lifecycle
-{
-  "data_retention": "90d"
-}
-
-PUT _data_stream/traces-apm.sampled*/_lifecycle
-{
-  "data_retention": "1h"
-}
-
-PUT _data_stream/metrics-apm.*.1m-*/_lifecycle
-{
-  "data_retention": "90d"
-}
-
-PUT _data_stream/metrics-apm.*.10m-*/_lifecycle
-{
-  "data_retention": "180d"
-}
-
-PUT _data_stream/metrics-apm.*.60m-*/_lifecycle
-{
-  "data_retention": "390d"
-}
-
-PUT _data_stream/metrics-apm.internal-*/_lifecycle
-{
-  "data_retention": "90d"
-}
-
-PUT _data_stream/metrics-apm.app.*/_lifecycle
-{
-  "data_retention": "90d"
-}
-
-PUT _data_stream/logs-apm.*/_lifecycle
-{
-  "data_retention": "10d"
+  "data_retention": <data_retention_period>
 }
 ----
 
+Default `<data_retention_period>` for each data stream is available in {observability-guide}/apm-ilm-how-to.html[this guide].
+
 // Link to fix if it exists
 This issue is fixed in 8.15.1 (https://github.com/elastic/elasticsearch/pull/112432[elastic/elasticsearch#112432]).