feat(relay): add configuration option to allow high cardinality tags in metric calls (#4805)

This PR adds a configuration option to allow high cardinality tags, such
as project id, in metrics.
High cardinality tags are prefixed with `hc.`. By default, it will
always strip those tags.


ref INGEST-140

Author: Litarnus

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+**Features**:
+
+- Add configuration to allow high cardinality tags in metrics. ([#4805](https://github.com/getsentry/relay/pull/4805))
+
 **Internal**:
 
 - Produce spans to the items topic. ([#4735](https://github.com/getsentry/relay/pull/4735))

Cargo.lock

@@ -193,7 +193,7 @@ smallvec = { version = "1.13.2", features = ["serde"] }
 socket2 = "0.5.8"
 sqlparser = "0.44.0"
 sqlx = { version = "0.8.2", default-features = false }
-statsdproxy = { version = "0.3.0", default-features = false }
+statsdproxy = { version = "0.4.1", default-features = false }
 symbolic-common = { version = "12.12.3", default-features = false }
 symbolic-unreal = { version = "12.12.3", default-features = false }
 syn = { version = "2.0.90" }

Cargo.toml

@@ -557,6 +557,14 @@ pub struct Metrics {
     ///
     /// Defaults to `true`.
     pub aggregate: bool,
+    /// Allows emission of metrics with high cardinality tags.
+    ///
+    /// High cardinality tags are dynamic values attached to metrics,
+    /// such as project IDs. When enabled, these tags will be included
+    /// in the emitted metrics. When disabled, the tags will be omitted.
+    ///
+    /// Defaults to `false`.
+    pub allow_high_cardinality_tags: bool,
 }
 
 impl Default for Metrics {
@@ -569,6 +577,7 @@ impl Default for Metrics {
             sample_rate: 1.0,
             periodic_secs: 5,
             aggregate: true,
+            allow_high_cardinality_tags: false,
         }
     }
 }
@@ -2123,6 +2132,11 @@ impl Config {
         self.values.metrics.aggregate
     }
 
+    /// Returns whether high cardinality tags should be removed before sending metrics.
+    pub fn metrics_allow_high_cardinality_tags(&self) -> bool {
+        self.values.metrics.allow_high_cardinality_tags
+    }
+
     /// Returns the interval for periodic metrics emitted from Relay.
     ///
     /// `None` if periodic metrics are disabled.