Adds documentation and changelog, and fixes minor lint

.chloggen/bounded_duration_sampler.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: processor/tailsampling
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: adds optional upper bound duration for sampling
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [26115]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

processor/tailsamplingprocessor/README.md

@@ -29,7 +29,7 @@ The following configuration options are required:
 
 Multiple policies exist today and it is straight forward to add more. These include:
 - `always_sample`: Sample all traces
-- `latency`: Sample based on the duration of the trace. The duration is determined by looking at the earliest start time and latest end time, without taking into consideration what happened in between.
+- `latency`: Sample based on the duration of the trace. The duration is determined by looking at the earliest start time and latest end time, without taking into consideration what happened in between. Supplying no upper bound will result in a policy sampling anything greater than `threshold_ms`.
 - `numeric_attribute`: Sample based on number attributes (resource and record)
 - `probabilistic`: Sample a percentage of traces. Read [a comparison with the Probabilistic Sampling Processor](#probabilistic-sampling-processor-compared-to-the-tail-sampling-processor-with-the-probabilistic-policy).
 - `status_code`: Sample based upon the status code (`OK`, `ERROR` or `UNSET`)

processor/tailsamplingprocessor/config.go

@@ -87,13 +87,15 @@ type AndSubPolicyCfg struct {
 	sharedPolicyCfg `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct
 }
 
+// TraceStateCfg holds the common configuration for trace states.
 type TraceStateCfg struct {
 	// Tag that the filter is going to be matching against.
 	Key string `mapstructure:"key"`
 	// Values indicate the set of values to use when matching against trace_state values.
 	Values []string `mapstructure:"values"`
 }
 
+// AndCfg holds the common configuration to all and policies.
 type AndCfg struct {
 	SubPolicyCfg []AndSubPolicyCfg `mapstructure:"and_sub_policy"`
 }