fix: stabilize local meta port allocation

Author: BohuTANG

src/meta/store/src/local.rs

@@ -233,23 +233,22 @@ impl LocalMetaService {
 }
 
 fn next_port() -> u16 {
-    let base = get_machine_unique_base_port();
-    let sequence = GlobalSequence::next() as u16;
-
-    let port_offset = sequence % 10_000;
-    let candidate_port = base.saturating_add(port_offset).max(19_000);
-
-    if is_port_available(candidate_port) {
-        return candidate_port;
-    }
-
     match find_available_port() {
         Ok(port) => {
-            warn!("Calculated port {candidate_port} not available, using {port} instead");
             port
         }
         Err(_) => {
-            warn!("No available ports found, returning calculated port {candidate_port}");
+            let base = get_machine_unique_base_port();
+            let sequence = GlobalSequence::next() as u16;
+
+            let port_offset = sequence % 10_000;
+            let candidate_port = base.saturating_add(port_offset).max(19_000);
+
+            if is_port_available(candidate_port) {
+                return candidate_port;
+            }
+
+            warn!("Failed to find available port, returning fallback port {candidate_port}");
             candidate_port
         }
     }