martin-g commented on code in PR #21742: URL: https://github.com/apache/datafusion/pull/21742#discussion_r3110199407
########## datafusion/physical-plan/src/spill/replayable_spill_input.rs: ########## @@ -0,0 +1,372 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +//! Utility for replaying a one-shot input `RecourdBatchStream` through spill. Review Comment: ```suggestion //! Utility for replaying a one-shot input `RecordBatchStream` through spill. ``` ########## datafusion/physical-plan/src/spill/replayable_spill_input.rs: ########## @@ -0,0 +1,372 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +//! Utility for replaying a one-shot input `RecourdBatchStream` through spill. +//! +//! See comments in [`ReplayableStreamSource`] for details. + +use std::pin::Pin; +use std::sync::Arc; +use std::sync::atomic::{AtomicU32, Ordering}; +use std::task::{Context, Poll}; + +use arrow::datatypes::SchemaRef; +use arrow::record_batch::RecordBatch; +use datafusion_common::{Result, internal_err}; +use datafusion_execution::RecordBatchStream; +use datafusion_execution::SendableRecordBatchStream; +use datafusion_execution::disk_manager::RefCountedTempFile; +use futures::Stream; +use parking_lot::Mutex; + +use crate::EmptyRecordBatchStream; +use crate::spill::in_progress_spill_file::InProgressSpillFile; +use crate::spill::spill_manager::SpillManager; + +const FIRST_PASS_ACTIVE_EPOCH: u32 = 1; +const POISONED_EPOCH: u32 = u32::MAX; + +/// Spill-backed replayable stream source. +/// +/// [`ReplayableStreamSource`] is constructed from an input stream, usually produced +/// by executing an input `ExecutionPlan`. +/// +/// - On the first pass, it evaluates the input stream, produces `RecordBatch`es, +/// caches those batches to a local spill file, and also forwards them to the +/// output. +/// - On subsequent passes, it reads directly from the spill file. +/// +/// ```text +/// first pass: +/// +/// RecordBatch stream +/// | +/// v +/// [batch] -> output +/// | +/// +----> spill file +/// +/// +/// later passes: +/// +/// spill file +/// | +/// v +/// [batch] -> output +/// ``` +/// +/// This is useful when an input stream must be replayed and: +/// - Re-evaluation is expensive because the input stream may come from a long +/// and complex pipeline. +/// - The parent operator is under memory pressure and cannot cache the input in +/// memory for replay. +pub(crate) struct ReplayableStreamSource { + schema: SchemaRef, + input: Option<SendableRecordBatchStream>, + spill_manager: SpillManager, + request_description: String, + /// 0 = unopened, 1 = first pass active, 2 = replayable/empty, MAX = poisoned + /// on execution errors. + epoch: Arc<AtomicU32>, + spill_file: Arc<Mutex<Option<RefCountedTempFile>>>, +} + +impl ReplayableStreamSource { + /// Creates a replayable stream producer over a one-shot input stream. + /// + /// It caches the input into a local spill file on the first pass, then + /// reads directly from that spill file on subsequent passes. + pub(crate) fn new( + input: SendableRecordBatchStream, + spill_manager: SpillManager, + request_description: impl Into<String>, + ) -> Self { + let schema = input.schema(); + Self { + schema, + input: Some(input), + spill_manager, + request_description: request_description.into(), + epoch: Arc::new(AtomicU32::new(0)), + spill_file: Arc::new(Mutex::new(None)), + } + } + + /// Opens the next pass over this input. + /// + /// The first call returns a stream that forwards upstream batches while + /// caching them to spill. Later calls return streams that read directly + /// from the completed spill file. + /// + /// # Note + /// Subsequent passes MUST be opened only after the initial pass is fully + /// consumed; otherwise, an error is returned. + pub(crate) fn open_pass(&mut self) -> Result<SendableRecordBatchStream> { + match self.epoch.load(Ordering::Relaxed) { Review Comment: Is `Relaxed` enough here? Acquire/Release would guarantee the ordering of the operations if more than 1 threads try to read this atomic integer. The code below uses pattern like: ```rust epoch_state.load(Relaxed); ... *spill_file_state.lock() = spill_file; epoch_state.store(epoch.saturating_add(1), Ordering::Relaxed); ``` The problem here is that the MutexGuard does not live long enough to cover the `epoch_state.store()` call and there is a chance another thread to be executed between the update of the Mutex and the `.store()` call. You may want to store the MutexGuard in a local variable. ########## datafusion/physical-plan/src/spill/replayable_spill_input.rs: ########## @@ -0,0 +1,372 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +//! Utility for replaying a one-shot input `RecourdBatchStream` through spill. +//! +//! See comments in [`ReplayableStreamSource`] for details. + +use std::pin::Pin; +use std::sync::Arc; +use std::sync::atomic::{AtomicU32, Ordering}; +use std::task::{Context, Poll}; + +use arrow::datatypes::SchemaRef; +use arrow::record_batch::RecordBatch; +use datafusion_common::{Result, internal_err}; +use datafusion_execution::RecordBatchStream; +use datafusion_execution::SendableRecordBatchStream; +use datafusion_execution::disk_manager::RefCountedTempFile; +use futures::Stream; +use parking_lot::Mutex; + +use crate::EmptyRecordBatchStream; +use crate::spill::in_progress_spill_file::InProgressSpillFile; +use crate::spill::spill_manager::SpillManager; + +const FIRST_PASS_ACTIVE_EPOCH: u32 = 1; +const POISONED_EPOCH: u32 = u32::MAX; + +/// Spill-backed replayable stream source. +/// +/// [`ReplayableStreamSource`] is constructed from an input stream, usually produced +/// by executing an input `ExecutionPlan`. +/// +/// - On the first pass, it evaluates the input stream, produces `RecordBatch`es, +/// caches those batches to a local spill file, and also forwards them to the +/// output. +/// - On subsequent passes, it reads directly from the spill file. +/// +/// ```text +/// first pass: +/// +/// RecordBatch stream +/// | +/// v +/// [batch] -> output +/// | +/// +----> spill file +/// +/// +/// later passes: +/// +/// spill file +/// | +/// v +/// [batch] -> output +/// ``` +/// +/// This is useful when an input stream must be replayed and: +/// - Re-evaluation is expensive because the input stream may come from a long +/// and complex pipeline. +/// - The parent operator is under memory pressure and cannot cache the input in +/// memory for replay. +pub(crate) struct ReplayableStreamSource { + schema: SchemaRef, + input: Option<SendableRecordBatchStream>, + spill_manager: SpillManager, + request_description: String, + /// 0 = unopened, 1 = first pass active, 2 = replayable/empty, MAX = poisoned + /// on execution errors. + epoch: Arc<AtomicU32>, + spill_file: Arc<Mutex<Option<RefCountedTempFile>>>, +} + +impl ReplayableStreamSource { + /// Creates a replayable stream producer over a one-shot input stream. + /// + /// It caches the input into a local spill file on the first pass, then + /// reads directly from that spill file on subsequent passes. + pub(crate) fn new( + input: SendableRecordBatchStream, + spill_manager: SpillManager, + request_description: impl Into<String>, + ) -> Self { + let schema = input.schema(); + Self { + schema, + input: Some(input), + spill_manager, + request_description: request_description.into(), + epoch: Arc::new(AtomicU32::new(0)), + spill_file: Arc::new(Mutex::new(None)), + } + } + + /// Opens the next pass over this input. + /// + /// The first call returns a stream that forwards upstream batches while + /// caching them to spill. Later calls return streams that read directly + /// from the completed spill file. + /// + /// # Note + /// Subsequent passes MUST be opened only after the initial pass is fully + /// consumed; otherwise, an error is returned. + pub(crate) fn open_pass(&mut self) -> Result<SendableRecordBatchStream> { + match self.epoch.load(Ordering::Relaxed) { + 0 => { + let Some(input) = self.input.take() else { Review Comment: ```suggestion if self.input.is_none() { ``` postpone the Option::take() until `spill_manager.create_in_progress_file()` finishes successfully. Otherwise the `input` might be consumed/taken and the `epoch` still `0`. ########## datafusion/physical-plan/src/joins/nested_loop_join.rs: ########## Review Comment: The docstring is obsolete. The spill logic has been moved to replayable_spill_input.rs ########## datafusion/physical-plan/src/spill/replayable_spill_input.rs: ########## @@ -0,0 +1,372 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +//! Utility for replaying a one-shot input `RecourdBatchStream` through spill. +//! +//! See comments in [`ReplayableStreamSource`] for details. + +use std::pin::Pin; +use std::sync::Arc; +use std::sync::atomic::{AtomicU32, Ordering}; +use std::task::{Context, Poll}; + +use arrow::datatypes::SchemaRef; +use arrow::record_batch::RecordBatch; +use datafusion_common::{Result, internal_err}; +use datafusion_execution::RecordBatchStream; +use datafusion_execution::SendableRecordBatchStream; +use datafusion_execution::disk_manager::RefCountedTempFile; +use futures::Stream; +use parking_lot::Mutex; + +use crate::EmptyRecordBatchStream; +use crate::spill::in_progress_spill_file::InProgressSpillFile; +use crate::spill::spill_manager::SpillManager; + +const FIRST_PASS_ACTIVE_EPOCH: u32 = 1; +const POISONED_EPOCH: u32 = u32::MAX; + +/// Spill-backed replayable stream source. +/// +/// [`ReplayableStreamSource`] is constructed from an input stream, usually produced +/// by executing an input `ExecutionPlan`. +/// +/// - On the first pass, it evaluates the input stream, produces `RecordBatch`es, +/// caches those batches to a local spill file, and also forwards them to the +/// output. +/// - On subsequent passes, it reads directly from the spill file. +/// +/// ```text +/// first pass: +/// +/// RecordBatch stream +/// | +/// v +/// [batch] -> output +/// | +/// +----> spill file +/// +/// +/// later passes: +/// +/// spill file +/// | +/// v +/// [batch] -> output +/// ``` +/// +/// This is useful when an input stream must be replayed and: +/// - Re-evaluation is expensive because the input stream may come from a long +/// and complex pipeline. +/// - The parent operator is under memory pressure and cannot cache the input in +/// memory for replay. +pub(crate) struct ReplayableStreamSource { + schema: SchemaRef, + input: Option<SendableRecordBatchStream>, + spill_manager: SpillManager, + request_description: String, + /// 0 = unopened, 1 = first pass active, 2 = replayable/empty, MAX = poisoned + /// on execution errors. + epoch: Arc<AtomicU32>, + spill_file: Arc<Mutex<Option<RefCountedTempFile>>>, +} + +impl ReplayableStreamSource { + /// Creates a replayable stream producer over a one-shot input stream. + /// + /// It caches the input into a local spill file on the first pass, then + /// reads directly from that spill file on subsequent passes. + pub(crate) fn new( + input: SendableRecordBatchStream, + spill_manager: SpillManager, + request_description: impl Into<String>, + ) -> Self { + let schema = input.schema(); + Self { + schema, + input: Some(input), + spill_manager, + request_description: request_description.into(), + epoch: Arc::new(AtomicU32::new(0)), + spill_file: Arc::new(Mutex::new(None)), + } + } + + /// Opens the next pass over this input. + /// + /// The first call returns a stream that forwards upstream batches while + /// caching them to spill. Later calls return streams that read directly + /// from the completed spill file. + /// + /// # Note + /// Subsequent passes MUST be opened only after the initial pass is fully + /// consumed; otherwise, an error is returned. + pub(crate) fn open_pass(&mut self) -> Result<SendableRecordBatchStream> { + match self.epoch.load(Ordering::Relaxed) { + 0 => { + let Some(input) = self.input.take() else { + return internal_err!( + "ReplayableStreamSource missing first-pass input" + ); + }; + let spill_file = self + .spill_manager + .create_in_progress_file(&self.request_description)?; + *self.spill_file.lock() = None; Review Comment: the second part of https://github.com/apache/datafusion/pull/21742/changes#r3110298802 ```suggestion let input = self .input .take() .expect("input was checked before creating the spill file"); *self.spill_file.lock() = None; ``` -- This is an automated message from the Apache Git Service. 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