refactor(obs): migrate metrics runtime/schema and tighten migration guards (#2584)

crates/obs/src/metrics/schema/scanner.rs

@@ -0,0 +1,72 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed 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.
+
+#![allow(dead_code)]
+
+use crate::{MetricDescriptor, MetricName, new_counter_md, new_gauge_md, subsystems};
+use std::sync::LazyLock;
+
+pub static SCANNER_BUCKET_SCANS_FINISHED_MD: LazyLock<MetricDescriptor> = LazyLock::new(|| {
+    new_counter_md(
+        MetricName::ScannerBucketScansFinished,
+        "Total number of bucket scans finished since server start",
+        &[],
+        subsystems::SCANNER,
+    )
+});
+
+pub static SCANNER_BUCKET_SCANS_STARTED_MD: LazyLock<MetricDescriptor> = LazyLock::new(|| {
+    new_counter_md(
+        MetricName::ScannerBucketScansStarted,
+        "Total number of bucket scans started since server start",
+        &[],
+        subsystems::SCANNER,
+    )
+});
+
+pub static SCANNER_DIRECTORIES_SCANNED_MD: LazyLock<MetricDescriptor> = LazyLock::new(|| {
+    new_counter_md(
+        MetricName::ScannerDirectoriesScanned,
+        "Total number of directories scanned since server start",
+        &[],
+        subsystems::SCANNER,
+    )
+});
+
+pub static SCANNER_OBJECTS_SCANNED_MD: LazyLock<MetricDescriptor> = LazyLock::new(|| {
+    new_counter_md(
+        MetricName::ScannerObjectsScanned,
+        "Total number of unique objects scanned since server start",
+        &[],
+        subsystems::SCANNER,
+    )
+});
+
+pub static SCANNER_VERSIONS_SCANNED_MD: LazyLock<MetricDescriptor> = LazyLock::new(|| {
+    new_counter_md(
+        MetricName::ScannerVersionsScanned,
+        "Total number of object versions scanned since server start",
+        &[],
+        subsystems::SCANNER,
+    )
+});
+
+pub static SCANNER_LAST_ACTIVITY_SECONDS_MD: LazyLock<MetricDescriptor> = LazyLock::new(|| {
+    new_gauge_md(
+        MetricName::ScannerLastActivitySeconds,
+        "Time elapsed (in seconds) since last scan activity.",
+        &[],
+        subsystems::SCANNER,
+    )
+});