refactor(config): normalize scanner env naming (#2129)

crates/config/README.md

@@ -49,6 +49,12 @@ Current guidance:
 - Deprecated example:
   - `RUSTFS_ENABLE_SCANNER` -> `RUSTFS_SCANNER_ENABLED`
   - `RUSTFS_ENABLE_HEAL` -> `RUSTFS_HEAL_ENABLED`
+  - `RUSTFS_DATA_SCANNER_START_DELAY_SECS` -> `RUSTFS_SCANNER_START_DELAY_SECS`
+
+## Scanner environment aliases
+
+- `RUSTFS_SCANNER_START_DELAY_SECS` (canonical)
+- `RUSTFS_DATA_SCANNER_START_DELAY_SECS` (deprecated alias for compatibility)
 
 ## 📄 License
 

crates/config/src/constants/scanner.rs

@@ -14,10 +14,15 @@
 
 use std::time::Duration;
 
-/// Environment variable name that specifies the data scanner start delay in seconds.
+/// Canonical environment variable name that specifies the scanner start delay in seconds.
 /// If set, this overrides the cycle interval derived from `RUSTFS_SCANNER_SPEED`.
 /// - Unit: seconds (u64).
-/// - Example: `export RUSTFS_DATA_SCANNER_START_DELAY_SECS=10`
+/// - Example: `export RUSTFS_SCANNER_START_DELAY_SECS=10`
+pub const ENV_SCANNER_START_DELAY_SECS: &str = "RUSTFS_SCANNER_START_DELAY_SECS";
+
+/// Deprecated compatibility alias for scanner start delay.
+/// Prefer `RUSTFS_SCANNER_START_DELAY_SECS`.
+#[deprecated(note = "Use RUSTFS_SCANNER_START_DELAY_SECS instead")]
 pub const ENV_DATA_SCANNER_START_DELAY_SECS: &str = "RUSTFS_DATA_SCANNER_START_DELAY_SECS";
 
 /// Environment variable that selects the scanner speed preset.

crates/scanner/src/scanner.rs

@@ -22,7 +22,10 @@ use crate::{DataUsageInfo, ScannerError};
 use chrono::{DateTime, Utc};
 use rustfs_common::heal_channel::HealScanMode;
 use rustfs_common::metrics::{CurrentCycle, Metric, Metrics, emit_scan_cycle_complete, global_metrics};
-use rustfs_config::{DEFAULT_SCANNER_SPEED, ENV_DATA_SCANNER_START_DELAY_SECS, ENV_SCANNER_SPEED, ScannerSpeed};
+use rustfs_config::DEFAULT_SCANNER_SPEED;
+use rustfs_config::ENV_SCANNER_SPEED;
+use rustfs_config::ENV_SCANNER_START_DELAY_SECS;
+use rustfs_config::ScannerSpeed;
 use rustfs_ecstore::StorageAPI as _;
 use rustfs_ecstore::config::com::{read_config, save_config};
 use rustfs_ecstore::disk::RUSTFS_META_BUCKET;
@@ -35,17 +38,25 @@ use tokio::time::{Duration, Instant};
 use tokio_util::sync::CancellationToken;
 use tracing::{debug, error, info, instrument, warn};
 
-/// Returns the base cycle interval. If `RUSTFS_DATA_SCANNER_START_DELAY_SECS`
-/// is set, it takes precedence; otherwise the value is derived from the
+const ENV_SCANNER_START_DELAY_SECS_DEPRECATED: &str = "RUSTFS_DATA_SCANNER_START_DELAY_SECS";
+
+/// Returns the base cycle interval. If `RUSTFS_SCANNER_START_DELAY_SECS`
+/// is set (or `RUSTFS_DATA_SCANNER_START_DELAY_SECS` as deprecated alias),
+/// it takes precedence; otherwise the value is derived from the
 /// `RUSTFS_SCANNER_SPEED` preset.
 fn cycle_interval() -> Duration {
-    if let Some(secs) = rustfs_utils::get_env_opt_u64(ENV_DATA_SCANNER_START_DELAY_SECS) {
+    if let Some(secs) = scanner_start_delay_secs() {
         return Duration::from_secs(secs);
     }
     let speed_str = rustfs_utils::get_env_str(ENV_SCANNER_SPEED, DEFAULT_SCANNER_SPEED);
     ScannerSpeed::from_env_str(&speed_str).cycle_interval()
 }
 
+fn scanner_start_delay_secs() -> Option<u64> {
+    let deprecated = [ENV_SCANNER_START_DELAY_SECS_DEPRECATED];
+    rustfs_utils::get_env_opt_u64_with_aliases(ENV_SCANNER_START_DELAY_SECS, &deprecated)
+}
+
 /// Compute a randomized inter-cycle sleep.
 // Delay is scan interval +- 10%, with a floor of 1 second.
 fn randomized_cycle_delay() -> Duration {

crates/utils/src/envs.rs

@@ -310,6 +310,28 @@ pub fn get_env_u64(key: &str, default: u64) -> u64 {
     env::var(key).ok().and_then(|v| v.parse().ok()).unwrap_or(default)
 }
 
+/// Retrieve an environment variable as an unsigned 64-bit integer, returning `None` if not set or parsing fails.
+/// Deprecated aliases are also supported with warning logging.
+///
+/// #Parameters
+/// - `key`: The canonical environment variable key to look up.
+/// - `deprecated`: A list of deprecated keys kept for compatibility.
+///
+/// #Returns
+/// - `Option<u64>`: The parsed value if a key is found and valid, otherwise `None`.
+///
+pub fn get_env_opt_u64_with_aliases(key: &str, deprecated: &[&str]) -> Option<u64> {
+    let (used_key, value) = resolve_env_with_aliases(key, deprecated)?;
+    value
+        .parse::<u64>()
+        .map_err(|_| {
+            log_once(&format!("env_invalid_u64:{used_key}"), || {
+                format!("Invalid u64 value for {used_key}: {value}. Using default behavior.")
+            });
+        })
+        .ok()
+}
+
 /// Retrieve an environment variable as a specific type, returning None if not set or parsing fails.
 ///
 /// #Parameters