Metrics examples to stop using global shutdown

examples/metrics-advanced/src/main.rs

@@ -8,7 +8,7 @@ use opentelemetry_sdk::metrics::{
 use opentelemetry_sdk::{runtime, Resource};
 use std::error::Error;
 
-fn init_meter_provider() {
+fn init_meter_provider() -> opentelemetry_sdk::metrics::SdkMeterProvider {
     // for example 1
     let my_view_rename_and_unit = |i: &Instrument| {
         if i.name == "my_histogram" {
@@ -61,12 +61,13 @@ fn init_meter_provider() {
         .with_view(my_view_drop_attributes)
         .with_view(my_view_change_aggregation)
         .build();
-    global::set_meter_provider(provider);
+    global::set_meter_provider(provider.clone());
+    provider
 }
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
-    init_meter_provider();
+    let meter_provider = init_meter_provider();
     let meter = global::meter("mylibraryname");
 
     // Example 1 - Rename metric using View.
@@ -153,6 +154,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     // Metrics are exported by default every 30 seconds when using stdout exporter,
     // however shutting down the MeterProvider here instantly flushes
     // the metrics, instead of waiting for the 30 sec interval.
-    global::shutdown_meter_provider();
+    meter_provider.shutdown()?;
     Ok(())
 }

examples/metrics-basic/src/main.rs

@@ -138,7 +138,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     // Metrics are exported by default every 30 seconds when using stdout exporter,
     // however shutting down the MeterProvider here instantly flushes
     // the metrics, instead of waiting for the 30 sec interval.
-    // global::shutdown_meter_provider();
     meter_provider.shutdown()?;
     Ok(())
 }

opentelemetry-otlp/examples/basic-otlp-http/src/main.rs

@@ -44,7 +44,7 @@ fn init_tracer() -> Result<sdktrace::Tracer, TraceError> {
         .install_batch(opentelemetry_sdk::runtime::Tokio)
 }
 
-fn init_metrics() -> Result<(), MetricsError> {
+fn init_metrics() -> Result<opentelemetry_sdk::metrics::SdkMeterProvider, MetricsError> {
     let export_config = opentelemetry_otlp::ExportConfig {
         endpoint: "http://localhost:4318/v1/metrics".to_string(),
         ..opentelemetry_otlp::ExportConfig::default()
@@ -57,7 +57,10 @@ fn init_metrics() -> Result<(), MetricsError> {
                 .with_export_config(export_config),
         )
         .build();
-    provider.map(|_| ())
+    match provider {
+        Ok(provider) => Ok(provider),
+        Err(err) => Err(err),
+    }
 }
 
 const LEMONS_KEY: Key = Key::from_static_str("ex.com/lemons");
@@ -88,6 +91,8 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
         result.err()
     );
 
+    let meter_provider = result.unwrap();
+
     // Opentelemetry will not provide a global API to manage the logger provider. Application users must manage the lifecycle of the logger provider on their own. Dropping logger providers will disable log emitting.
     let logger_provider = init_logs().unwrap();
 
@@ -120,7 +125,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 
     global::shutdown_tracer_provider();
     logger_provider.shutdown();
-    global::shutdown_meter_provider();
+    meter_provider.shutdown()?;
 
     Ok(())
 }

opentelemetry-otlp/examples/basic-otlp/src/main.rs

@@ -31,7 +31,7 @@ fn init_tracer() -> Result<sdktrace::Tracer, TraceError> {
         .install_batch(runtime::Tokio)
 }
 
-fn init_metrics() -> Result<(), MetricsError> {
+fn init_metrics() -> Result<opentelemetry_sdk::metrics::SdkMeterProvider, MetricsError> {
     let export_config = ExportConfig {
         endpoint: "http://localhost:4317".to_string(),
         ..ExportConfig::default()
@@ -49,7 +49,7 @@ fn init_metrics() -> Result<(), MetricsError> {
         )]))
         .build();
     match provider {
-        Ok(_provider) => Ok(()),
+        Ok(provider) => Ok(provider),
         Err(err) => Err(err),
     }
 }
@@ -103,8 +103,9 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
         "Init metrics failed with error: {:?}",
         result.err()
     );
+    let meter_provider = result.unwrap();
 
-    // Initialize logs, which sets the global loggerprovider.
+    // Initialize logs and save the logger_provider.
     let logger_provider = init_logs().unwrap();
 
     // Create a new OpenTelemetryLogBridge using the above LoggerProvider.
@@ -148,7 +149,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 
     global::shutdown_tracer_provider();
     logger_provider.shutdown();
-    global::shutdown_meter_provider();
+    meter_provider.shutdown()?;
 
     Ok(())
 }

opentelemetry-sdk/src/metrics/meter_provider.rs

@@ -397,13 +397,13 @@ mod tests {
         let provider = super::SdkMeterProvider::builder()
             .with_reader(reader.clone())
             .build();
-        global::set_meter_provider(provider);
+        global::set_meter_provider(provider.clone());
         assert!(!reader.is_shutdown());
         // create a meter and an instrument
         let meter = global::meter("test");
         let counter = meter.u64_counter("test_counter").init();
         // no need to drop a meter for meter_provider shutdown
-        global::shutdown_meter_provider();
+        provider.shutdown().unwrap();
         assert!(reader.is_shutdown());
         // TODO Fix: the instrument is still available, and can be used.
         // While the reader is shutdown, and no collect is happening

opentelemetry-stdout/examples/basic.rs

@@ -24,11 +24,12 @@ fn init_trace() {
 }
 
 #[cfg(feature = "metrics")]
-fn init_metrics() {
+fn init_metrics() -> opentelemetry_sdk::metrics::SdkMeterProvider {
     let exporter = opentelemetry_stdout::MetricsExporter::default();
     let reader = PeriodicReader::builder(exporter, runtime::Tokio).build();
     let provider = SdkMeterProvider::builder().with_reader(reader).build();
-    global::set_meter_provider(provider);
+    global::set_meter_provider(provider.clone());
+    provider
 }
 
 #[cfg(feature = "logs")]
@@ -77,7 +78,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     init_trace();
 
     #[cfg(feature = "metrics")]
-    init_metrics();
+    let meter_provider = init_metrics();
 
     #[cfg(feature = "logs")]
     let logger_provider = init_logs();
@@ -103,7 +104,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     global::shutdown_tracer_provider();
 
     #[cfg(feature = "metrics")]
-    global::shutdown_meter_provider();
+    meter_provider.shutdown()?;
 
     #[cfg(feature = "logs")]
     drop(logger_provider);