Skip to content

[apm]: Document sampling.tail.discard_on_write_failure config #4908

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: 8.x
Choose a base branch
from
+15 −1
Open

[apm]: Document sampling.tail.discard_on_write_failure config #4908

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
03961cc
[apm]: Document sampling.tail.discard_on_write_failure config
isaacaflores2 Jun 27, 2025
13637d4
[apm]: Add changes to storage limit behavior based on the Discard On …
isaacaflores2 Jul 1, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 15 additions & 1 deletion docs/en/observability/apm/configure/sampling.asciidoc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -67,7 +67,7 @@ This final policy is used to catch remaining trace events that don't match a str
=== Storage limit
The amount of storage space allocated for trace events matching tail sampling policies. Caution: Setting this limit higher than the allowed space may cause APM Server to become unhealthy.

If the configured storage limit is insufficient, it logs "configured storage limit reached". The event will bypass sampling and will always be indexed when storage limit is reached.
If the configured storage limit is insufficient, it logs "configured storage limit reached". When the storage limit is reached, the event will be indexed or discarded based on the <<sampling-tail-discard_on_write_failure-{input-type},Discard On Write Failure>> configuration.

Default: `3GB`. (text)

Expand All @@ -76,6 +76,20 @@ Default: `3GB`. (text)
| Fleet-managed | `Storage limit`
|====

[float]
[id="sampling-tail-discard_on_write_failure-{input-type}"]
=== Discard On Write Failure
Defines the indexing behavior when trace events fail to be written to storage (for example, when the storage limit is reached).
When set to `false`, traces bypass sampling and are always indexed, which significantly increases the indexing load.
When set to `true`, traces are discarded, causing data loss which can result in broken traces.

Default: `false`. (bool)

|====
| APM Server binary | `sampling.tail.discard_on_write_failure`
| Fleet-managed (version 8.19+) | `Discard On Write Failure`
|====

// end::tbs-top[]

[float]
Expand Down