fix for staging size metrics

- to subtract the size of the arrow file removed from staging
fix for GET /cache
- to return error in case global cache is not set

Author: nikhilsinhaparseable

server/src/handlers/http/logstream.rs

@@ -338,6 +338,17 @@ pub async fn put_retention(
 
 pub async fn get_cache_enabled(req: HttpRequest) -> Result<impl Responder, StreamError> {
     let stream_name: String = req.match_info().get("logstream").unwrap().parse().unwrap();
+    
+    match CONFIG.parseable.mode {
+        Mode::Ingest | Mode::All => {
+            if CONFIG.parseable.local_cache_path.is_none() {
+                return Err(StreamError::CacheNotEnabled(stream_name));
+            }
+        }
+        _ => {}
+    }
+    
+
     let cache_enabled = STREAM_INFO.cache_enabled(&stream_name)?;
     Ok((web::Json(cache_enabled), StatusCode::OK))
 }

server/src/storage/staging.rs

@@ -247,10 +247,16 @@ pub fn convert_disk_files_to_parquet(
         writer.close()?;
 
         for file in files {
-            if fs::remove_file(file).is_err() {
+            let file_size = file.metadata().unwrap().len();
+            let file_type = file.extension().unwrap().to_str().unwrap();
+
+            if fs::remove_file(file.clone()).is_err() {
                 log::error!("Failed to delete file. Unstable state");
                 process::abort()
             }
+            metrics::STORAGE_SIZE
+                .with_label_values(&["staging", stream, file_type])
+                .sub(file_size as i64);
         }
     }