feat(vector sink): add multiple endpoint strategies

Author: fpytloun

changelog.d/vector_sink_multiple_backends.feature.md

@@ -0,0 +1,3 @@
+Add support for configuring multiple endpoints in the `vector` sink via the new `addresses` option, enabling built-in load balancing and failover across downstream Vector instances.
+
+authors: fpytloun

src/sinks/util/service/health.rs

@@ -29,7 +29,7 @@ const UNHEALTHY_AMOUNT_OF_ERRORS: usize = 5;
 /// Options for determining the health of an endpoint.
 #[serde_as]
 #[configurable_component]
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug)]
 #[serde(rename_all = "snake_case")]
 pub struct HealthConfig {
     /// Initial delay between attempts to reactivate endpoints once they become unhealthy.
@@ -46,6 +46,15 @@ pub struct HealthConfig {
     pub retry_max_duration_secs: Duration,
 }
 
+impl Default for HealthConfig {
+    fn default() -> Self {
+        Self {
+            retry_initial_backoff_secs: default_retry_initial_backoff_secs(),
+            retry_max_duration_secs: default_retry_max_duration_secs(),
+        }
+    }
+}
+
 const fn default_retry_initial_backoff_secs() -> u64 {
     RETRY_INITIAL_BACKOFF_SECONDS_DEFAULT
 }
@@ -329,4 +338,12 @@ mod tests {
         counters.inc_healthy();
         assert!(counters.healthy(snapshot).is_ok());
     }
+
+    #[test]
+    fn default_health_config_matches_documented_defaults() {
+        let config = HealthConfig::default();
+
+        assert_eq!(config.retry_initial_backoff_secs, 1);
+        assert_eq!(config.retry_max_duration_secs, Duration::from_secs(3_600));
+    }
 }