[Logs API] Remove global provider for Logs

opentelemetry-otlp/CHANGELOG.md

@@ -17,6 +17,11 @@
 
 [#1568]: https://github.com/open-telemetry/opentelemetry-rust/pull/1568
 
+### Changed
+ - **Breaking** Remove global provider for Logs [#1691](https://github.com/open-telemetry/opentelemetry-rust/pull/1691/)
+      - The method OtlpLogPipeline::install_simple() and OtlpLogPipeline::install_batch() now return `LoggerProvider` instead of
+      `Logger`. Refer to the [basic-otlp](https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry-otlp/examples/basic-otlp/src/main.rs) and [basic-otlp-http](https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry-otlp/examples/basic-otlp-http/src/main.rs) examples for how to initialize OTLP Log Exporter to use with OpenTelemetryLogBridge and OpenTelemetryTracingBridge respectively.
+
 ## v0.15.0
 
 ### Added

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

@@ -15,7 +15,7 @@ use std::error::Error;
 use tracing::info;
 use tracing_subscriber::prelude::*;
 
-fn init_logs() -> Result<sdklogs::Logger, opentelemetry::logs::LogError> {
+fn init_logs() -> Result<sdklogs::LoggerProvider, opentelemetry::logs::LogError> {
     let service_name = env!("CARGO_BIN_NAME");
     opentelemetry_otlp::new_pipeline()
         .logging()
@@ -76,13 +76,12 @@ static COMMON_ATTRIBUTES: Lazy<[KeyValue; 4]> = Lazy::new(|| {
 async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     let _ = init_tracer()?;
     let _ = init_metrics()?;
-    let _ = init_logs();
+    // 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();
 
     let tracer = global::tracer("ex.com/basic");
     let meter = global::meter("ex.com/basic");
 
-    // configure the global logger to use our opentelemetry logger
-    let logger_provider = opentelemetry::global::logger_provider();
     let layer = OpenTelemetryTracingBridge::new(&logger_provider);
     tracing_subscriber::registry().with(layer).init();
 
@@ -108,7 +107,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     histogram.record(5.5, COMMON_ATTRIBUTES.as_ref());
 
     global::shutdown_tracer_provider();
-    global::shutdown_logger_provider();
+    logger_provider.shutdown();
     global::shutdown_meter_provider();
 
     Ok(())

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

@@ -54,7 +54,7 @@ fn init_metrics() -> Result<(), MetricsError> {
     }
 }
 
-fn init_logs() -> Result<opentelemetry_sdk::logs::Logger, LogError> {
+fn init_logs() -> Result<opentelemetry_sdk::logs::LoggerProvider, LogError> {
     let service_name = env!("CARGO_BIN_NAME");
     opentelemetry_otlp::new_pipeline()
         .logging()
@@ -93,10 +93,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     let _ = init_metrics()?;
 
     // Initialize logs, which sets the global loggerprovider.
-    let _ = init_logs();
-
-    // Retrieve the global LoggerProvider.
-    let logger_provider = global::logger_provider();
+    let logger_provider = init_logs().unwrap();
 
     // Create a new OpenTelemetryLogBridge using the above LoggerProvider.
     let otel_log_appender = OpenTelemetryLogBridge::new(&logger_provider);
@@ -141,7 +138,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     info!(target: "my-target", "hello from {}. My price is {}", "apple", 1.99);
 
     global::shutdown_tracer_provider();
-    global::shutdown_logger_provider();
+    logger_provider.shutdown();
     global::shutdown_meter_provider();
 
     Ok(())

opentelemetry-otlp/src/logs.rs

@@ -10,12 +10,10 @@ use crate::exporter::http::HttpExporterBuilder;
 
 use crate::{NoExporterConfig, OtlpPipeline};
 use async_trait::async_trait;
-use std::{borrow::Cow, fmt::Debug};
+use std::fmt::Debug;
+
+use opentelemetry::logs::LogError;
 
-use opentelemetry::{
-    global,
-    logs::{LogError, LoggerProvider},
-};
 use opentelemetry_sdk::{export::logs::LogData, runtime::RuntimeChannel};
 
 /// Compression algorithm to use, defaults to none.
@@ -147,7 +145,7 @@ impl OtlpLogPipeline<LogExporterBuilder> {
     /// Returns a [`Logger`] with the name `opentelemetry-otlp` and the current crate version.
     ///
     /// [`Logger`]: opentelemetry_sdk::logs::Logger
-    pub fn install_simple(self) -> Result<opentelemetry_sdk::logs::Logger, LogError> {
+    pub fn install_simple(self) -> Result<opentelemetry_sdk::logs::LoggerProvider, LogError> {
         Ok(build_simple_with_exporter(
             self.exporter_builder.build_log_exporter()?,
             self.log_config,
@@ -163,7 +161,7 @@ impl OtlpLogPipeline<LogExporterBuilder> {
     pub fn install_batch<R: RuntimeChannel>(
         self,
         runtime: R,
-    ) -> Result<opentelemetry_sdk::logs::Logger, LogError> {
+    ) -> Result<opentelemetry_sdk::logs::LoggerProvider, LogError> {
         Ok(build_batch_with_exporter(
             self.exporter_builder.build_log_exporter()?,
             self.log_config,
@@ -176,27 +174,22 @@ impl OtlpLogPipeline<LogExporterBuilder> {
 fn build_simple_with_exporter(
     exporter: LogExporter,
     log_config: Option<opentelemetry_sdk::logs::Config>,
-) -> opentelemetry_sdk::logs::Logger {
+) -> opentelemetry_sdk::logs::LoggerProvider {
     let mut provider_builder =
         opentelemetry_sdk::logs::LoggerProvider::builder().with_simple_exporter(exporter);
     if let Some(config) = log_config {
         provider_builder = provider_builder.with_config(config);
     }
-    let provider = provider_builder.build();
-    let logger = provider
-        .logger_builder(Cow::Borrowed("opentelemetry-otlp"))
-        .with_version(Cow::Borrowed(env!("CARGO_PKG_VERSION")))
-        .build();
-    let _ = global::set_logger_provider(provider);
-    logger
+    // logger would be created in the tracing appender
+    provider_builder.build()
 }
 
 fn build_batch_with_exporter<R: RuntimeChannel>(
     exporter: LogExporter,
     log_config: Option<opentelemetry_sdk::logs::Config>,
     runtime: R,
     batch_config: Option<opentelemetry_sdk::logs::BatchConfig>,
-) -> opentelemetry_sdk::logs::Logger {
+) -> opentelemetry_sdk::logs::LoggerProvider {
     let mut provider_builder = opentelemetry_sdk::logs::LoggerProvider::builder();
     let batch_processor = opentelemetry_sdk::logs::BatchLogProcessor::builder(exporter, runtime)
         .with_batch_config(batch_config.unwrap_or_default())
@@ -206,11 +199,6 @@ fn build_batch_with_exporter<R: RuntimeChannel>(
     if let Some(config) = log_config {
         provider_builder = provider_builder.with_config(config);
     }
-    let provider = provider_builder.build();
-    let logger = provider
-        .logger_builder(Cow::Borrowed("opentelemetry-otlp"))
-        .with_version(Cow::Borrowed(env!("CARGO_PKG_VERSION")))
-        .build();
-    let _ = global::set_logger_provider(provider);
-    logger
+    // logger would be created in the tracing appender
+    provider_builder.build()
 }

opentelemetry-sdk/src/logs/log_emitter.rs

@@ -266,8 +266,8 @@ mod tests {
     use crate::Resource;
 
     use super::*;
-    use opentelemetry::global::{logger, set_logger_provider, shutdown_logger_provider};
-    use opentelemetry::logs::{Logger, LoggerProvider as _};
+    use opentelemetry::logs::Logger;
+    use opentelemetry::logs::LoggerProvider as _;
     use opentelemetry::{Key, KeyValue, Value};
     use std::fmt::{Debug, Formatter};
     use std::sync::atomic::AtomicU64;
@@ -481,74 +481,27 @@ mod tests {
         // Arrange
         let shutdown_called = Arc::new(Mutex::new(false));
         let flush_called = Arc::new(Mutex::new(false));
-        let signal_to_end = Arc::new(Mutex::new(false));
-        let signal_to_thread_started = Arc::new(Mutex::new(false));
         let logger_provider = LoggerProvider::builder()
             .with_log_processor(LazyLogProcessor::new(
                 shutdown_called.clone(),
                 flush_called.clone(),
             ))
             .build();
-        set_logger_provider(logger_provider);
+        //set_logger_provider(logger_provider);
+        let logger1 = logger_provider.logger("test-logger1");
+        let logger2 = logger_provider.logger("test-logger2");
 
-        // Act
-        let logger1 = logger("test-logger1");
-        let logger2 = logger("test-logger2");
+        // Acts
         logger1.emit(LogRecord::default());
         logger2.emit(LogRecord::default());
 
-        let signal_to_end_clone = signal_to_end.clone();
-        let signal_to_thread_started_clone = signal_to_thread_started.clone();
-
-        let handle = thread::spawn(move || {
-            let logger3 = logger("test-logger3");
-            loop {
-                // signal the main thread that this thread has started.
-                *signal_to_thread_started_clone.lock().unwrap() = true;
-                logger3.emit(LogRecord::default());
-                if *signal_to_end_clone.lock().unwrap() {
-                    break;
-                }
-            }
-        });
-
-        // wait for the spawned thread to start before calling shutdown This is
-        // very important - if shutdown is called before the spawned thread
-        // obtains its logger, then the logger will be no-op one, and the test
-        // will pass, but it will not be testing the intended scenario.
-        while !*signal_to_thread_started.lock().unwrap() {
-            thread::sleep(std::time::Duration::from_millis(10));
-        }
-
-        // Intentionally *not* calling shutdown/flush on the provider, but
-        // instead relying on shutdown_logger_provider which causes the global
-        // provider to be dropped, leading to the sdk logger provider's drop to
-        // be called, which is expected to call shutdown on processors.
-        shutdown_logger_provider();
+        // explicitly calling shutdown on logger_provider. This will
+        // indeed do the shutdown, even if there are loggers still alive.
+        logger_provider.shutdown();
 
         // Assert
 
-        // shutdown_logger_provider is necessary but not sufficient, as loggers
-        // hold on to the the provider (via inner provider clones).
-        assert!(!*shutdown_called.lock().unwrap());
-
-        // flush is never called by the sdk.
-        assert!(!*flush_called.lock().unwrap());
-
-        // Drop one of the logger. Not enough!
-        drop(logger1);
-        assert!(!*shutdown_called.lock().unwrap());
-
-        // drop logger2, which is the only remaining logger in this thread.
-        // Still not enough!
-        drop(logger2);
-        assert!(!*shutdown_called.lock().unwrap());
-
-        // now signal the spawned thread to end, which causes it to drop its
-        // logger. Since that is the last logger, the provider (inner provider)
-        // is finally dropped, triggering shutdown
-        *signal_to_end.lock().unwrap() = true;
-        handle.join().unwrap();
+        // shutdown is called.
         assert!(*shutdown_called.lock().unwrap());
 
         // flush is never called by the sdk.

opentelemetry/CHANGELOG.md

@@ -10,6 +10,16 @@
 ### Removed
 
 - Remove `urlencoding` crate dependency. [#1613](https://github.com/open-telemetry/opentelemetry-rust/pull/1613)
+- Remove global providers for Logs [$1691](https://github.com/open-telemetry/opentelemetry-rust/pull/1691)
+    LoggerProviders are not meant for end users to get loggers from. It is only required for the log bridges.
+    Below global constructs for the logs are removed from API:
+        - opentelemetry::global::logger
+        - opentelemetry::global::set_logger_provider
+        - opentelemetry::global::shutdown_logger_provider
+        - opentelemetry::global::logger_provider
+        - opentelemetry::global::GlobalLoggerProvider
+        - opentelemetry::global::ObjectSafeLoggerProvider 
+    For creating appenders using Logging bridge API, refer to the opentelemetry-tracing-appender [example](https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry-appender-tracing/examples/basic.rs)
 
 ### Changed
 

opentelemetry/Cargo.toml

@@ -40,7 +40,7 @@ logs_level_enabled = ["logs"]
 otel_unstable = []
 
 [dev-dependencies]
-opentelemetry_sdk = { path = "../opentelemetry-sdk" } # for documentation tests
+opentelemetry_sdk = { path = "../opentelemetry-sdk", features = ["logs_level_enabled"]} # for documentation tests
 criterion = { version = "0.3" }
 
 [[bench]]