Consolidate execution monitoring examples (#18142) (#18846)

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- part of ##18142.

## Rationale for this change
This PR is for consolidating all the `execution_monitoring` examples
(mem_pool_exec_plan, mem_pool_tracking, tracing) into a single example
binary. We are agreed on the pattern and we can apply it to the
remaining examples

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Co-authored-by: Sergey Zhukov <[email protected]>

Author: cj-zhukov

datafusion-examples/README.md

@@ -69,8 +69,9 @@ cargo run --example dataframe
 - [`examples/custom_data_source/file_stream_provider.rs`](examples/custom_data_source/file_stream_provider.rs): Run a query on `FileStreamProvider` which implements `StreamProvider` for reading and writing to arbitrary stream sources / sinks.
 - [`flight/sql_server.rs`](examples/flight/sql_server.rs): Run DataFusion as a standalone process and execute SQL queries from Flight and and FlightSQL (e.g. JDBC) clients
 - [`examples/builtin_functions/function_factory.rs`](examples/builtin_functions/function_factory.rs): Register `CREATE FUNCTION` handler to implement SQL macros
-- [`memory_pool_tracking.rs`](examples/memory_pool_tracking.rs): Demonstrates TrackConsumersPool for memory tracking and debugging with enhanced error messages
-- [`memory_pool_execution_plan.rs`](examples/memory_pool_execution_plan.rs): Shows how to implement memory-aware ExecutionPlan with memory reservation and spilling
+- [`examples/execution_monitoring/memory_pool_tracking.rs`](examples/execution_monitoring/memory_pool_tracking.rs): Demonstrates TrackConsumersPool for memory tracking and debugging with enhanced error messages
+- [`examples/execution_monitoring/memory_pool_execution_plan.rs`](examples/execution_monitoring/memory_pool_execution_plan.rs): Shows how to implement memory-aware ExecutionPlan with memory reservation and spilling
+- [`examples/execution_monitoring/tracing.rs`](examples/execution_monitoring/tracing.rs): Demonstrates the tracing injection feature for the DataFusion runtime
 - [`examples/query_planning/optimizer_rule.rs`](examples/query_planning/optimizer_rule.rs): Use a custom OptimizerRule to replace certain predicates
 - [`examples/data_io/parquet_embedded_index.rs`](examples/data_io/parquet_embedded_index.rs): Store a custom index inside a Parquet file and use it to speed up queries
 - [`examples/data_io/parquet_encrypted.rs`](examples/data_io/parquet_encrypted.rs): Read and write encrypted Parquet files using DataFusion

datafusion-examples/examples/execution_monitoring/main.rs

@@ -0,0 +1,107 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+//! # These examples of memory and performance management
+//!
+//! These examples demonstrate memory and performance management.
+//!
+//! ## Usage
+//! ```bash
+//! cargo run --example execution_monitoring -- [mem_pool_exec_plan|mem_pool_tracking|tracing]
+//! ```
+//!
+//! Each subcommand runs a corresponding example:
+//! - `mem_pool_exec_plan` — shows how to implement memory-aware ExecutionPlan with memory reservation and spilling
+//! - `mem_pool_tracking` — demonstrates TrackConsumersPool for memory tracking and debugging with enhanced error messages
+//! - `tracing` — demonstrates the tracing injection feature for the DataFusion runtime
+
+mod memory_pool_execution_plan;
+mod memory_pool_tracking;
+mod tracing;
+
+use std::str::FromStr;
+
+use datafusion::error::{DataFusionError, Result};
+
+enum ExampleKind {
+    MemoryPoolExecutionPlan,
+    MemoryPoolTracking,
+    Tracing,
+}
+
+impl AsRef<str> for ExampleKind {
+    fn as_ref(&self) -> &str {
+        match self {
+            Self::MemoryPoolExecutionPlan => "mem_pool_exec_plan",
+            Self::MemoryPoolTracking => "mem_pool_tracking",
+            Self::Tracing => "tracing",
+        }
+    }
+}
+
+impl FromStr for ExampleKind {
+    type Err = DataFusionError;
+
+    fn from_str(s: &str) -> Result<Self> {
+        match s {
+            "mem_pool_exec_plan" => Ok(Self::MemoryPoolExecutionPlan),
+            "mem_pool_tracking" => Ok(Self::MemoryPoolTracking),
+            "tracing" => Ok(Self::Tracing),
+            _ => Err(DataFusionError::Execution(format!("Unknown example: {s}"))),
+        }
+    }
+}
+
+impl ExampleKind {
+    const ALL: [Self; 3] = [
+        Self::MemoryPoolExecutionPlan,
+        Self::MemoryPoolTracking,
+        Self::Tracing,
+    ];
+
+    const EXAMPLE_NAME: &str = "execution_monitoring";
+
+    fn variants() -> Vec<&'static str> {
+        Self::ALL.iter().map(|x| x.as_ref()).collect()
+    }
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let usage = format!(
+        "Usage: cargo run --example {} -- [{}]",
+        ExampleKind::EXAMPLE_NAME,
+        ExampleKind::variants().join("|")
+    );
+
+    let arg = std::env::args().nth(1).ok_or_else(|| {
+        eprintln!("{usage}");
+        DataFusionError::Execution("Missing argument".to_string())
+    })?;
+
+    match arg.parse::<ExampleKind>()? {
+        ExampleKind::MemoryPoolExecutionPlan => {
+            memory_pool_execution_plan::memory_pool_execution_plan().await?
+        }
+        ExampleKind::MemoryPoolTracking => {
+            memory_pool_tracking::mem_pool_tracking().await?
+        }
+        ExampleKind::Tracing => tracing::tracing().await?,
+    }
+
+    Ok(())
+}

…s/examples/memory_pool_execution_plan.rs …monitoring/memory_pool_execution_plan.rsdatafusion-examples/examples/memory_pool_execution_plan.rs renamed to datafusion-examples/examples/execution_monitoring/memory_pool_execution_plan.rs datafusion-examples/examples/memory_pool_execution_plan.rs renamed to datafusion-examples/examples/execution_monitoring/memory_pool_execution_plan.rs

@@ -15,6 +15,8 @@
 // specific language governing permissions and limitations
 // under the License.
 
+//! See `main.rs` for how to run it.
+//!
 //! This example demonstrates how to implement custom ExecutionPlans that properly
 //! use memory tracking through TrackConsumersPool.
 //!
@@ -44,8 +46,8 @@ use std::any::Any;
 use std::fmt;
 use std::sync::Arc;
 
-#[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
+/// Shows how to implement memory-aware ExecutionPlan with memory reservation and spilling
+pub async fn memory_pool_execution_plan() -> Result<()> {
     println!("=== DataFusion ExecutionPlan Memory Tracking Example ===\n");
 
     // Set up a runtime with memory tracking

…xamples/examples/memory_pool_tracking.rs …ution_monitoring/memory_pool_tracking.rsdatafusion-examples/examples/memory_pool_tracking.rs renamed to datafusion-examples/examples/execution_monitoring/memory_pool_tracking.rs datafusion-examples/examples/memory_pool_tracking.rs renamed to datafusion-examples/examples/execution_monitoring/memory_pool_tracking.rs

@@ -15,6 +15,8 @@
 // specific language governing permissions and limitations
 // under the License.
 
+//! See `main.rs` for how to run it.
+//!
 //! This example demonstrates how to use TrackConsumersPool for memory tracking and debugging.
 //!
 //! The TrackConsumersPool provides enhanced error messages that show the top memory consumers
@@ -24,11 +26,12 @@
 //!
 //! * [`automatic_usage_example`]: Shows how to use RuntimeEnvBuilder to automatically enable memory tracking
 
+use datafusion::error::Result;
 use datafusion::execution::runtime_env::RuntimeEnvBuilder;
 use datafusion::prelude::*;
 
-#[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
+/// Demonstrates TrackConsumersPool for memory tracking and debugging with enhanced error messages
+pub async fn mem_pool_tracking() -> Result<()> {
     println!("=== DataFusion Memory Pool Tracking Example ===\n");
 
     // Example 1: Automatic Usage with RuntimeEnvBuilder
@@ -41,7 +44,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 ///
 /// This shows the recommended way to use TrackConsumersPool through RuntimeEnvBuilder,
 /// which automatically creates a TrackConsumersPool with sensible defaults.
-async fn automatic_usage_example() -> datafusion::error::Result<()> {
+async fn automatic_usage_example() -> Result<()> {
     println!("Example 1: Automatic Usage with RuntimeEnvBuilder");
     println!("------------------------------------------------");
 

datafusion-examples/examples/tracing.rs …examples/execution_monitoring/tracing.rsdatafusion-examples/examples/tracing.rs renamed to datafusion-examples/examples/execution_monitoring/tracing.rs datafusion-examples/examples/tracing.rs renamed to datafusion-examples/examples/execution_monitoring/tracing.rs

@@ -15,6 +15,8 @@
 // specific language governing permissions and limitations
 // under the License.
 
+//! See `main.rs` for how to run it.
+//!
 //! This example demonstrates the tracing injection feature for the DataFusion runtime.
 //! Tasks spawned on new threads behave differently depending on whether a tracer is injected.
 //! The log output clearly distinguishes the two cases.
@@ -61,8 +63,8 @@ use std::any::Any;
 use std::sync::Arc;
 use tracing::{info, instrument, Instrument, Level, Span};
 
-#[tokio::main]
-async fn main() -> Result<()> {
+/// Demonstrates the tracing injection feature for the DataFusion runtime
+pub async fn tracing() -> Result<()> {
     // Initialize tracing subscriber with thread info.
     tracing_subscriber::fmt()
         .with_thread_ids(true)