feat(dynamic_samping): Adjust sample rate by envelope header's sample_rate [INGEST-1395]

CHANGELOG.md

@@ -5,6 +5,7 @@
 **Features**:
 
 - Extract metrics also from trace-sampled transactions. ([#1317](https://github.com/getsentry/relay/pull/1317))
+- Adjust sample rate by envelope header's sample_rate. ([#1327](https://github.com/getsentry/relay/pull/1327))
 
 **Bug Fixes**:
 

relay-common/Cargo.toml

@@ -23,6 +23,7 @@ relay-log = { path = "../relay-log" }
 sentry-types = "0.20.0"
 schemars = { version = "0.8.1", features = ["uuid", "chrono"], optional = true }
 serde = { version = "1.0.114", features = ["derive"] }
+serde_json = "1.0.55"
 
 [dev-dependencies]
 serde_test = "1.0.125"

relay-common/src/lib.rs

@@ -13,6 +13,7 @@ mod constants;
 mod glob;
 mod project;
 mod retry;
+mod serde;
 mod time;
 mod utils;
 
@@ -21,6 +22,7 @@ pub use crate::constants::*;
 pub use crate::glob::*;
 pub use crate::project::*;
 pub use crate::retry::*;
+pub use crate::serde::*;
 pub use crate::time::*;
 pub use crate::utils::*;
 

relay-common/src/serde.rs

@@ -0,0 +1,71 @@
+use serde::ser::Serializer;
+use serde::{Deserialize, Serialize};
+
+/// A wrapper type that is able to deserialize its inner value from a nested JSON string.
+///
+/// For example, this struct:
+///
+/// ```rust
+/// # use relay_common::JsonStringifiedValue;
+/// use serde::Deserialize;
+///
+/// #[derive(Deserialize)]
+/// struct TraceContext {
+///     sample_rate: JsonStringifiedValue<f64>,
+/// }
+/// ```
+///
+/// ...deserializes from `{"sample_rate": "1.0"}` and `{"sample_rate": 1.0}`, and serializes to
+/// `{"sample_rate": "1.0"}`
+///
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd)]
+pub struct JsonStringifiedValue<T>(pub T);
+
+impl<'de, T> Deserialize<'de> for JsonStringifiedValue<T>
+where
+    for<'de2> T: Deserialize<'de2>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        #[derive(Deserialize)]
+        #[serde(untagged)]
+        enum Helper<T> {
+            Verbatim(T),
+            // can't change this to borrowed string, otherwise deserialization within an
+            // ErrorBoundary silently fails for some reason
+            String(String),
+        }
+
+        let helper = Helper::<T>::deserialize(deserializer)?;
+
+        match helper {
+            Helper::Verbatim(value) => Ok(JsonStringifiedValue(value)),
+            Helper::String(value) => {
+                let rv = serde_json::from_str(&value)
+                    .map_err(|e| serde::de::Error::custom(e.to_string()))?;
+                Ok(JsonStringifiedValue(rv))
+            }
+        }
+    }
+}
+
+impl<T: Serialize> Serialize for JsonStringifiedValue<T> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let string =
+            serde_json::to_string(&self.0).map_err(|e| serde::ser::Error::custom(e.to_string()))?;
+        string.serialize(serializer)
+    }
+}
+
+#[test]
+fn test_basic() {
+    let value = serde_json::from_str::<JsonStringifiedValue<f32>>("42.0").unwrap();
+    assert_eq!(value.0, 42.0);
+    let value = serde_json::from_str::<JsonStringifiedValue<f32>>("\"42.0\"").unwrap();
+    assert_eq!(value.0, 42.0);
+}

relay-general/Cargo.toml

@@ -31,7 +31,7 @@ relay-general-derive = { path = "derive" }
 schemars = { version = "0.8.1", features = ["uuid", "chrono"], optional = true }
 sentry-release-parser = { version = "1.3.1" }
 serde = { version = "1.0.114", features = ["derive"] }
-serde_json = "1.0.55"
+serde_json = { version = "1.0.55", features = ["raw_value"] }
 serde_urlencoded = "0.5.5"
 sha-1 = "0.8.1"
 smallvec = { version = "1.4.0", features = ["serde"] }

relay-general/src/protocol/contexts.rs

@@ -496,6 +496,12 @@ pub struct TraceContext {
     /// excluding its immediate child spans.
     pub exclusive_time: Annotated<f64>,
 
+    /// The SDK-side sample rate as reported in the envelope's `trace.sample_rate` header.
+    ///
+    /// The server takes this field from envelope headers and writes it back into the event. SDKs
+    /// should not ever send this value.
+    pub client_sample_rate: Annotated<f64>,
+
     /// Additional arbitrary fields for forwards compatibility.
     #[metastructure(additional_properties, retain = "true", pii = "maybe")]
     pub other: Object<Value>,
@@ -697,6 +703,13 @@ impl Contexts {
             .value_mut()
             .get_or_insert_with(|| ContextInner(context_builder()))
     }
+
+    pub fn get_context_mut<S>(&mut self, key: S) -> Option<&mut Context>
+    where
+        S: AsRef<str>,
+    {
+        Some(&mut self.get_mut(key.as_ref())?.value_mut().as_mut()?.0)
+    }
 }
 
 impl std::ops::Deref for Contexts {
@@ -933,6 +946,7 @@ fn test_trace_context_roundtrip() {
   "op": "http",
   "status": "ok",
   "exclusive_time": 0.0,
+  "client_sample_rate": 0.5,
   "other": "value",
   "type": "trace"
 }"#;
@@ -943,6 +957,7 @@ fn test_trace_context_roundtrip() {
         op: Annotated::new("http".into()),
         status: Annotated::new(SpanStatus::Ok),
         exclusive_time: Annotated::new(0.0),
+        client_sample_rate: Annotated::new(0.5),
         other: {
             let mut map = Object::new();
             map.insert(

relay-general/tests/snapshots/test_fixtures__event_schema.snap

@@ -1,5 +1,6 @@
 ---
 source: relay-general/tests/test_fixtures.rs
+assertion_line: 106
 expression: event_json_schema()
 ---
 {
@@ -2727,6 +2728,15 @@ expression: event_json_schema()
             "trace_id"
           ],
           "properties": {
+            "client_sample_rate": {
+              "description": " The SDK-side sample rate as reported in the envelope's `trace.sample_rate` header.\n\n The server takes this field from envelope headers and writes it back into the event. SDKs\n should not ever send this value.",
+              "default": null,
+              "type": [
+                "number",
+                "null"
+              ],
+              "format": "double"
+            },
             "exclusive_time": {
               "description": " The amount of time in milliseconds spent in this transaction span,\n excluding its immediate child spans.",
               "default": null,