Configure tail-based sampling
editConfigure tail-based sampling
editEnable tail-based sampling in the APM integration settings. When enabled, trace events are mapped to sampling policies. Each sampling policy must specify a sample rate, and can optionally specify other conditions. All of the policy conditions must be true for a trace event to match it.
Trace events are matched to policies in the order specified.
Each policy list must conclude with a default policy — one that only specifies a sample rate.
This default policy is used to catch remaining trace events that don’t match a stricter policy.
Requiring this default policy ensures that traces are only dropped intentionally.
If you enable tail-based sampling and send a transaction that does not match any of the policies,
APM Server will reject the transaction with the error no matching policy
.
Please note that from version 8.3.1
APM Server implements a default storage limit of 3GB,
but, due to how the limit is calculated and enforced the actual disk space may still grow slightly
over the limit.
Example configuration
editThis example defines three tail-based sampling polices:
- sample_rate: 1 service.environment: production trace.name: "GET /very_important_route" - sample_rate: .01 service.environment: production trace.name: "GET /not_important_route" - sample_rate: .1
Samples 100% of traces in |
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Samples 1% of traces in |
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Default policy to sample all remaining traces at 10%, e.g. traces in a different environment, like |
Configuration reference
editTop-level tail-based sampling settings:
(bool) Enable and disable tail-based sampling. Default: |
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(duration) Synchronization interval for multiple APM Servers. Should be in the order of tens of seconds or low minutes. Default: |
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( Required when tail-based sampling is enabled. |
Policy settings:
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(int) The sample rate to apply to trace events matching this policy. Required in each policy. The sample rate must be greater than |
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(string) The trace name for events to match a policy.
A match occurs when the configured |
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(string) The trace outcome for events to match a policy.
A match occurs when the configured |
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(string) The service name for events to match a policy. |
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(string) The service environment for events to match a policy. |