[pbs-devel] [PATCH proxmox-backup] tape/restore: optimize chunk restore behaviour

Dominik Csapak d.csapak at proxmox.com
Tue May 4 12:21:47 CEST 2021


by checking the 'checked_chunks' before trying to write to disk
and by doing the existance check in the parallel handler. This way,
we do not have to check the existance of a chunk multiple times
(if multiple source datastores gets restored to the same target
datastore) and also we do not have to wait on the stat before reading
the next chunk.

We have to change the &WorkerTask to an Arc though, otherwise we
cannot log to the worker from the parallel handler

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
 src/api2/tape/drive.rs   |  2 +-
 src/api2/tape/restore.rs | 72 ++++++++++++++++++++++------------------
 2 files changed, 41 insertions(+), 33 deletions(-)

diff --git a/src/api2/tape/drive.rs b/src/api2/tape/drive.rs
index c97de61a..9cf36b37 100644
--- a/src/api2/tape/drive.rs
+++ b/src/api2/tape/drive.rs
@@ -1336,7 +1336,7 @@ pub fn catalog_media(
             drive.read_label()?; // skip over labels - we already read them above
 
             let mut checked_chunks = HashMap::new();
-            restore_media(&worker, &mut drive, &media_id, None, &mut checked_chunks, verbose)?;
+            restore_media(worker, &mut drive, &media_id, None, &mut checked_chunks, verbose)?;
 
             Ok(())
         },
diff --git a/src/api2/tape/restore.rs b/src/api2/tape/restore.rs
index 2614c68a..1dd6ba11 100644
--- a/src/api2/tape/restore.rs
+++ b/src/api2/tape/restore.rs
@@ -334,7 +334,7 @@ pub fn restore(
 
             for media_id in media_id_list.iter() {
                 request_and_restore_media(
-                    &worker,
+                    worker.clone(),
                     media_id,
                     &drive_config,
                     &drive,
@@ -368,7 +368,7 @@ pub fn restore(
 
 /// Request and restore complete media without using existing catalog (create catalog instead)
 pub fn request_and_restore_media(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     media_id: &MediaId,
     drive_config: &SectionConfigData,
     drive_name: &str,
@@ -388,7 +388,7 @@ pub fn request_and_restore_media(
         .and_then(|userid| lookup_user_email(userid))
         .or_else(|| lookup_user_email(&authid.clone().into()));
 
-    let (mut drive, info) = request_and_load_media(worker, &drive_config, &drive_name, &media_id.label, &email)?;
+    let (mut drive, info) = request_and_load_media(&worker, &drive_config, &drive_name, &media_id.label, &email)?;
 
     match info.media_set_label {
         None => {
@@ -424,7 +424,7 @@ pub fn request_and_restore_media(
 ///
 /// Only create the catalog if target is None.
 pub fn restore_media(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     drive: &mut Box<dyn TapeDriver>,
     media_id: &MediaId,
     target: Option<(&DataStoreMap, &Authid)>,
@@ -452,7 +452,7 @@ pub fn restore_media(
             Ok(reader) => reader,
         };
 
-        restore_archive(worker, reader, current_file_number, target, &mut catalog, checked_chunks_map, verbose)?;
+        restore_archive(worker.clone(), reader, current_file_number, target, &mut catalog, checked_chunks_map, verbose)?;
     }
 
     MediaCatalog::finish_temporary_database(status_path, &media_id.label.uuid, true)?;
@@ -461,7 +461,7 @@ pub fn restore_media(
 }
 
 fn restore_archive<'a>(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     mut reader: Box<dyn 'a + TapeRead>,
     current_file_number: u64,
     target: Option<(&DataStoreMap, &Authid)>,
@@ -520,7 +520,7 @@ fn restore_archive<'a>(
                     if is_new {
                         task_log!(worker, "restore snapshot {}", backup_dir);
 
-                        match restore_snapshot_archive(worker, reader, &path, &datastore, checked_chunks) {
+                        match restore_snapshot_archive(worker.clone(), reader, &path, &datastore, checked_chunks) {
                             Err(err) => {
                                 std::fs::remove_dir_all(&path)?;
                                 bail!("restore snapshot {} failed - {}", backup_dir, err);
@@ -574,9 +574,9 @@ fn restore_archive<'a>(
                     .or_insert(HashSet::new());
 
                 let chunks = if let Some(datastore) = datastore {
-                    restore_chunk_archive(worker, reader, datastore, checked_chunks, verbose)?
+                    restore_chunk_archive(worker.clone(), reader, datastore, checked_chunks, verbose)?
                 } else {
-                    scan_chunk_archive(worker, reader, verbose)?
+                    scan_chunk_archive(worker.clone(), reader, verbose)?
                 };
 
                 if let Some(chunks) = chunks {
@@ -619,7 +619,7 @@ fn restore_archive<'a>(
 
 // Read chunk archive without restoring data - just record contained chunks
 fn scan_chunk_archive<'a>(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     reader: Box<dyn 'a + TapeRead>,
     verbose: bool,
 ) -> Result<Option<Vec<[u8;32]>>, Error> {
@@ -642,7 +642,7 @@ fn scan_chunk_archive<'a>(
 
                 // check if this is an aborted stream without end marker
                 if let Ok(false) = reader.has_end_marker() {
-                    worker.log("missing stream end marker".to_string());
+                    task_log!(worker, "missing stream end marker");
                     return Ok(None);
                 }
 
@@ -664,7 +664,7 @@ fn scan_chunk_archive<'a>(
 }
 
 fn restore_chunk_archive<'a>(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     reader: Box<dyn 'a + TapeRead>,
     datastore: Arc<DataStore>,
     checked_chunks: &mut HashSet<[u8;32]>,
@@ -676,25 +676,38 @@ fn restore_chunk_archive<'a>(
     let mut decoder = ChunkArchiveDecoder::new(reader);
 
     let datastore2 = datastore.clone();
+    let start_time = std::time::SystemTime::now();
+    let bytes = Arc::new(std::sync::atomic::AtomicU64::new(0));
+    let bytes2 = bytes.clone();
+
+    let worker2 = worker.clone();
+
     let writer_pool = ParallelHandler::new(
         "tape restore chunk writer",
         4,
         move |(chunk, digest): (DataBlob, [u8; 32])| {
-            // println!("verify and write {}", proxmox::tools::digest_to_hex(&digest));
-            chunk.verify_crc()?;
-            if chunk.crypt_mode()? == CryptMode::None {
-                chunk.decode(None, Some(&digest))?; // verify digest
-            }
+            let chunk_exists = datastore2.cond_touch_chunk(&digest, false)?;
+            if !chunk_exists {
+                if verbose {
+                    task_log!(worker2, "Insert chunk: {}", proxmox::tools::digest_to_hex(&digest));
+                }
+                bytes2.fetch_add(chunk.raw_size(), std::sync::atomic::Ordering::SeqCst);
+                // println!("verify and write {}", proxmox::tools::digest_to_hex(&digest));
+                chunk.verify_crc()?;
+                if chunk.crypt_mode()? == CryptMode::None {
+                    chunk.decode(None, Some(&digest))?; // verify digest
+                }
 
-            datastore2.insert_chunk(&chunk, &digest)?;
+                datastore2.insert_chunk(&chunk, &digest)?;
+            } else if verbose {
+                task_log!(worker2, "Found existing chunk: {}", proxmox::tools::digest_to_hex(&digest));
+            }
             Ok(())
         },
     );
 
     let verify_and_write_channel = writer_pool.channel();
 
-    let start_time = std::time::SystemTime::now();
-    let mut bytes = 0;
 
     loop {
         let (digest, blob) = match decoder.next_chunk() {
@@ -710,7 +723,7 @@ fn restore_chunk_archive<'a>(
 
                 // check if this is an aborted stream without end marker
                 if let Ok(false) = reader.has_end_marker() {
-                    worker.log("missing stream end marker".to_string());
+                    task_log!(worker, "missing stream end marker");
                     return Ok(None);
                 }
 
@@ -721,17 +734,10 @@ fn restore_chunk_archive<'a>(
 
         worker.check_abort()?;
 
-        let chunk_exists = datastore.cond_touch_chunk(&digest, false)?;
-        if !chunk_exists {
-             if verbose {
-                task_log!(worker, "Insert chunk: {}", proxmox::tools::digest_to_hex(&digest));
-            }
-            bytes += blob.raw_size();
+        if !checked_chunks.contains(&digest) {
             verify_and_write_channel.send((blob, digest.clone()))?;
-         } else if verbose {
-            task_log!(worker, "Found existing chunk: {}", proxmox::tools::digest_to_hex(&digest));
+            checked_chunks.insert(digest.clone());
         }
-        checked_chunks.insert(digest.clone());
         chunks.push(digest);
     }
 
@@ -741,6 +747,8 @@ fn restore_chunk_archive<'a>(
 
     let elapsed = start_time.elapsed()?.as_secs_f64();
 
+    let bytes = bytes.load(std::sync::atomic::Ordering::SeqCst);
+
     task_log!(
         worker,
         "restored {} bytes ({:.2} MB/s)",
@@ -752,7 +760,7 @@ fn restore_chunk_archive<'a>(
 }
 
 fn restore_snapshot_archive<'a>(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     reader: Box<dyn 'a + TapeRead>,
     snapshot_path: &Path,
     datastore: &DataStore,
@@ -782,7 +790,7 @@ fn restore_snapshot_archive<'a>(
 }
 
 fn try_restore_snapshot_archive<R: pxar::decoder::SeqRead>(
-    worker: &WorkerTask,
+    worker: Arc<WorkerTask>,
     decoder: &mut pxar::decoder::sync::Decoder<R>,
     snapshot_path: &Path,
     _datastore: &DataStore,
-- 
2.20.1






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