Add redis OTEL metrics

This adds support exporting OTEL metrics and adds some
basic monitoring of the various redis queues.

Author: jaymell

server/Cargo.lock

@@ -33,11 +33,11 @@ once_cell = "1.18.0"
 figment = { version = "0.10", features = ["toml", "env", "test"] }
 tracing = "0.1.35"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
-tracing-opentelemetry = "0.23.0"
-opentelemetry = "0.22.0"
-opentelemetry_sdk = { version = "0.22.1", features = ["rt-tokio"] }
-opentelemetry-http = "0.11.0"
-opentelemetry-otlp = { version = "0.15.0" }
+tracing-opentelemetry = "0.24.0"
+opentelemetry = { version = "0.23.0", features = ["metrics"] }
+opentelemetry_sdk = { version = "0.23.0", features = ["rt-tokio"] }
+opentelemetry-http = "0.12.0"
+opentelemetry-otlp = { version = "0.16.0", features = ["metrics"] }
 validator = { version = "0.16.0", features = ["derive"] }
 jwt-simple = "0.11.6"
 ed25519-compact = "2.1.1"
@@ -72,6 +72,7 @@ omniqueue = { git = "https://github.com/svix/omniqueue-rs", rev = "75e5a9510ad33
 # Not a well-known author, and no longer gets updates => pinned.
 # Switch to hyper-http-proxy when upgrading hyper to 1.0.
 hyper-proxy = { version = "=0.9.1", default-features = false, features = ["openssl-tls"] }
+hex = "0.4.3"
 
 [target.'cfg(not(target_env = "msvc"))'.dependencies]
 tikv-jemallocator = { version = "0.5", optional = true }

server/svix-server/Cargo.toml

@@ -13,12 +13,14 @@ use std::{
 
 use aide::axum::ApiRouter;
 use cfg::ConfigurationInner;
+use once_cell::sync::Lazy;
 use opentelemetry_otlp::WithExportConfig;
-use opentelemetry_sdk::runtime::Tokio;
+use opentelemetry_sdk::{metrics::SdkMeterProvider, runtime::Tokio};
 use queue::TaskQueueProducer;
 use redis::RedisManager;
 use sea_orm::DatabaseConnection;
 use sentry::integrations::tracing::EventFilter;
+use svix_ksuid::{KsuidLike, KsuidMs};
 use tower::layer::layer_fn;
 use tower_http::{
     cors::{AllowHeaders, Any, CorsLayer},
@@ -44,6 +46,7 @@ pub mod core;
 pub mod db;
 pub mod error;
 pub mod expired_message_cleaner;
+pub mod metrics;
 pub mod openapi;
 pub mod queue;
 pub mod redis;
@@ -54,6 +57,9 @@ const CRATE_NAME: &str = env!("CARGO_CRATE_NAME");
 
 pub static SHUTTING_DOWN: AtomicBool = AtomicBool::new(false);
 
+pub static INSTANCE_ID: Lazy<String> =
+    Lazy::new(|| hex::encode(KsuidMs::new(None, None).to_string()));
+
 async fn graceful_shutdown_handler() {
     let ctrl_c = async {
         tokio::signal::ctrl_c()
@@ -83,6 +89,8 @@ async fn graceful_shutdown_handler() {
 
 #[tracing::instrument(name = "app_start", level = "trace", skip_all)]
 pub async fn run(cfg: Configuration, listener: Option<TcpListener>) {
+    let _metrics = setup_metrics(&cfg);
+
     run_with_prefix(None, cfg, listener).await
 }
 
@@ -325,6 +333,32 @@ pub fn setup_tracing(
     (registry, sentry_guard)
 }
 
+pub fn setup_metrics(cfg: &ConfigurationInner) -> Option<SdkMeterProvider> {
+    cfg.opentelemetry_address.as_ref().map(|addr| {
+        let exporter = opentelemetry_otlp::new_exporter()
+            .tonic()
+            .with_endpoint(addr);
+
+        opentelemetry_otlp::new_pipeline()
+            .metrics(Tokio)
+            .with_delta_temporality()
+            .with_exporter(exporter)
+            .with_resource(opentelemetry_sdk::Resource::new(vec![
+                opentelemetry::KeyValue::new(
+                    "service.name",
+                    cfg.opentelemetry_service_name.clone(),
+                ),
+                opentelemetry::KeyValue::new("instance_id", INSTANCE_ID.to_owned()),
+                opentelemetry::KeyValue::new(
+                    "service.version",
+                    option_env!("GITHUB_SHA").unwrap_or("unknown"),
+                ),
+            ]))
+            .build()
+            .unwrap()
+    })
+}
+
 pub fn setup_tracing_for_tests() {
     use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 

server/svix-server/src/lib.rs

@@ -0,0 +1,13 @@
+mod redis;
+
+pub fn init_metric<T, E: std::fmt::Debug>(result: Result<T, E>) -> Option<T> {
+    match result {
+        Ok(t) => Some(t),
+        Err(e) => {
+            tracing::error!(error = ?e, "Failed to initialize metric");
+            None
+        }
+    }
+}
+
+pub use self::redis::{RedisQueueMetrics, RedisQueueType};

server/svix-server/src/metrics/mod.rs

@@ -0,0 +1,119 @@
+use opentelemetry::metrics::{Meter, ObservableGauge};
+use redis::{streams::StreamPendingReply, AsyncCommands as _};
+
+use super::init_metric;
+use crate::{
+    error::{Error, Result},
+    redis::RedisManager,
+};
+
+pub enum RedisQueueType<'a> {
+    Stream(&'a str),
+    StreamPending { stream: &'a str, group: &'a str },
+    List(&'a str),
+    SortedSet(&'a str),
+}
+
+impl<'a> RedisQueueType<'a> {
+    pub async fn queue_depth(&self, redis: &RedisManager) -> Result<u64> {
+        let mut conn = redis.get().await?;
+        match self {
+            RedisQueueType::Stream(q) => conn
+                .xlen(q)
+                .await
+                .map_err(|e| Error::queue(format!("Failed to query queue depth: {e}"))),
+            RedisQueueType::StreamPending { stream, group } => {
+                let reply: StreamPendingReply = conn.xpending(stream, group).await?;
+                Ok(reply.count() as _)
+            }
+            RedisQueueType::List(q) => conn
+                .llen(q)
+                .await
+                .map_err(|e| Error::queue(format!("Failed to query queue depth: {e}"))),
+            RedisQueueType::SortedSet(q) => conn
+                .zcard(q)
+                .await
+                .map_err(|e| Error::queue(format!("Failed to query queue depth: {e}"))),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct RedisQueueMetrics {
+    main_queue: Option<ObservableGauge<u64>>,
+    pending_queue: Option<ObservableGauge<u64>>,
+    delayed_queue: Option<ObservableGauge<u64>>,
+}
+
+impl RedisQueueMetrics {
+    pub fn new(meter: &Meter) -> Self {
+        let main_queue = init_metric(
+            meter
+                .u64_observable_gauge("svix.queue.depth_main")
+                .try_init(),
+        );
+
+        let pending_queue = init_metric(
+            meter
+                .u64_observable_gauge("svix.queue.pending_msgs")
+                .try_init(),
+        );
+
+        let delayed_queue = init_metric(
+            meter
+                .u64_observable_gauge("svix.queue.depth_delayed")
+                .try_init(),
+        );
+
+        Self {
+            main_queue,
+            pending_queue,
+            delayed_queue,
+        }
+    }
+    pub async fn record(
+        &self,
+        redis: &RedisManager,
+        main_queue: &RedisQueueType<'_>,
+        pending_queue: &RedisQueueType<'_>,
+        delayed_queue: &RedisQueueType<'_>,
+    ) {
+        main_queue
+            .queue_depth(redis)
+            .await
+            .map(|d| self.record_main_queue_depth(d))
+            .unwrap_or_else(|e| {
+                tracing::warn!("Failed to record queue depth: {e}");
+            });
+        pending_queue
+            .queue_depth(redis)
+            .await
+            .map(|d| self.record_pending_queue_depth(d))
+            .unwrap_or_else(|e| {
+                tracing::warn!("Failed to record queue depth: {e}");
+            });
+        delayed_queue
+            .queue_depth(redis)
+            .await
+            .map(|d| self.record_delayed_queue_depth(d))
+            .unwrap_or_else(|e| {
+                tracing::warn!("Failed to record queue depth: {e}");
+            });
+    }
+
+    fn record_main_queue_depth(&self, value: u64) {
+        if let Some(recorder) = &self.main_queue {
+            recorder.observe(value, &[]);
+        }
+    }
+    fn record_pending_queue_depth(&self, value: u64) {
+        if let Some(recorder) = &self.pending_queue {
+            recorder.observe(value, &[]);
+        }
+    }
+    fn record_delayed_queue_depth(&self, value: u64) {
+        if let Some(recorder) = &self.delayed_queue {
+            recorder.observe(value, &[]);
+        }
+    }
+}

server/svix-server/src/metrics/redis.rs

@@ -0,0 +1,9 @@
+mod redis;
+mod worker;
+
+pub use svix_server_core::metrics::*;
+
+pub use self::{
+    redis::{RedisQueueMetrics, RedisQueueType},
+    worker::WorkerMetrics,
+};