feat: allow configurable duration for data push to S3 (#626)

create parquet file by grouping all arrow files (in staging) for the duration 
provided in env variable P_STORAGE_UPLOAD_INTERVAL also check 
if arrow files vector is not empty, then sort the arrow files and create key 
for parquet file from last file from sorted arrow files vector

Fixes #616

server/src/storage/staging.rs

@@ -124,6 +124,7 @@ impl StorageDir {
         // hashmap <time, vec[paths]> but exclude where hot filename matches
         let mut grouped_arrow_file: HashMap<PathBuf, Vec<PathBuf>> = HashMap::new();
         let mut arrow_files = self.arrow_files();
+
         arrow_files.retain(|path| {
             !path
                 .file_name()
@@ -132,12 +133,17 @@ impl StorageDir {
                 .unwrap()
                 .ends_with(&hot_filename)
         });
-        for arrow_file_path in arrow_files {
-            let key = Self::arrow_path_to_parquet(&arrow_file_path);
-            grouped_arrow_file
-                .entry(key)
-                .or_default()
-                .push(arrow_file_path);
+
+        //check if arrow files is not empty, fetch the parquet file path from last file from sorted arrow file list
+        if !(arrow_files.is_empty()) {
+            arrow_files.sort();
+            let key = Self::arrow_path_to_parquet(arrow_files.last().unwrap());
+            for arrow_file_path in arrow_files {
+                grouped_arrow_file
+                    .entry(key.clone())
+                    .or_default()
+                    .push(arrow_file_path);
+            }
         }
 
         grouped_arrow_file
@@ -201,7 +207,6 @@ pub fn convert_disk_files_to_parquet(
         let record_reader = MergedReverseRecordReader::try_new(&files).unwrap();
 
         let parquet_file = fs::File::create(&parquet_path).map_err(|_| MoveDataError::Create)?;
-
         let props = parquet_writer_props().build();
         let merged_schema = record_reader.merged_schema();
         schemas.push(merged_schema.clone());