split batches for RawKV batch put / delete requests (#501)

 

Signed-off-by: lance6716 <lance6716@gmail.com>

Author: lance6716

src/raw/requests.rs

@@ -10,7 +10,6 @@ use crate::proto::tikvpb::tikv_client::TikvClient;
 use crate::range_request;
 use crate::region::RegionWithLeader;
 use crate::request::plan::ResponseWithShard;
-use crate::request::Collect;
 use crate::request::CollectSingle;
 use crate::request::DefaultProcessor;
 use crate::request::KvRequest;
@@ -19,6 +18,7 @@ use crate::request::Process;
 use crate::request::RangeRequest;
 use crate::request::Shardable;
 use crate::request::SingleKey;
+use crate::request::{Batchable, Collect};
 use crate::shardable_key;
 use crate::shardable_keys;
 use crate::shardable_range;
@@ -35,12 +35,15 @@ use crate::Result;
 use crate::Value;
 use async_trait::async_trait;
 use futures::stream::BoxStream;
+use futures::{stream, StreamExt};
 use std::any::Any;
 use std::ops::Range;
 use std::sync::Arc;
 use std::time::Duration;
 use tonic::transport::Channel;
 
+const RAW_KV_REQUEST_BATCH_SIZE: u64 = 16 * 1024; // 16 KB
+
 pub fn new_raw_get_request(key: Vec<u8>, cf: Option<ColumnFamily>) -> kvrpcpb::RawGetRequest {
     let mut req = kvrpcpb::RawGetRequest::default();
     req.key = key;
@@ -188,6 +191,14 @@ impl KvRequest for kvrpcpb::RawBatchPutRequest {
     type Response = kvrpcpb::RawBatchPutResponse;
 }
 
+impl Batchable for kvrpcpb::RawBatchPutRequest {
+    type Item = (kvrpcpb::KvPair, u64);
+
+    fn item_size(item: &Self::Item) -> u64 {
+        (item.0.key.len() + item.0.value.len()) as u64
+    }
+}
+
 impl Shardable for kvrpcpb::RawBatchPutRequest {
     type Shard = Vec<(kvrpcpb::KvPair, u64)>;
 
@@ -204,6 +215,16 @@ impl Shardable for kvrpcpb::RawBatchPutRequest {
             .collect();
         kv_ttl.sort_by(|a, b| a.0.key.cmp(&b.0.key));
         region_stream_for_keys(kv_ttl.into_iter(), pd_client.clone())
+            .flat_map(|result| match result {
+                Ok((keys, region)) => stream::iter(kvrpcpb::RawBatchPutRequest::batches(
+                    keys,
+                    RAW_KV_REQUEST_BATCH_SIZE,
+                ))
+                .map(move |batch| Ok((batch, region.clone())))
+                .boxed(),
+                Err(e) => stream::iter(Err(e)).boxed(),
+            })
+            .boxed()
     }
 
     fn apply_shard(&mut self, shard: Self::Shard) {
@@ -212,6 +233,18 @@ impl Shardable for kvrpcpb::RawBatchPutRequest {
         self.ttls = ttls;
     }
 
+    fn clone_then_apply_shard(&self, shard: Self::Shard) -> Self
+    where
+        Self: Sized + Clone,
+    {
+        let mut cloned = Self::default();
+        cloned.context = self.context.clone();
+        cloned.cf = self.cf.clone();
+        cloned.for_cas = self.for_cas;
+        cloned.apply_shard(shard);
+        cloned
+    }
+
     fn apply_store(&mut self, store: &RegionStore) -> Result<()> {
         self.set_leader(&store.region_with_leader)
     }
@@ -257,7 +290,56 @@ impl KvRequest for kvrpcpb::RawBatchDeleteRequest {
     type Response = kvrpcpb::RawBatchDeleteResponse;
 }
 
-shardable_keys!(kvrpcpb::RawBatchDeleteRequest);
+impl Batchable for kvrpcpb::RawBatchDeleteRequest {
+    type Item = Vec<u8>;
+
+    fn item_size(item: &Self::Item) -> u64 {
+        item.len() as u64
+    }
+}
+
+impl Shardable for kvrpcpb::RawBatchDeleteRequest {
+    type Shard = Vec<Vec<u8>>;
+
+    fn shards(
+        &self,
+        pd_client: &Arc<impl PdClient>,
+    ) -> BoxStream<'static, Result<(Self::Shard, RegionWithLeader)>> {
+        let mut keys = self.keys.clone();
+        keys.sort();
+        region_stream_for_keys(keys.into_iter(), pd_client.clone())
+            .flat_map(|result| match result {
+                Ok((keys, region)) => stream::iter(kvrpcpb::RawBatchDeleteRequest::batches(
+                    keys,
+                    RAW_KV_REQUEST_BATCH_SIZE,
+                ))
+                .map(move |batch| Ok((batch, region.clone())))
+                .boxed(),
+                Err(e) => stream::iter(Err(e)).boxed(),
+            })
+            .boxed()
+    }
+
+    fn apply_shard(&mut self, shard: Self::Shard) {
+        self.keys = shard;
+    }
+
+    fn clone_then_apply_shard(&self, shard: Self::Shard) -> Self
+    where
+        Self: Sized + Clone,
+    {
+        let mut cloned = Self::default();
+        cloned.context = self.context.clone();
+        cloned.cf = self.cf.clone();
+        cloned.for_cas = self.for_cas;
+        cloned.apply_shard(shard);
+        cloned
+    }
+
+    fn apply_store(&mut self, store: &RegionStore) -> Result<()> {
+        self.set_leader(&store.region_with_leader)
+    }
+}
 
 pub fn new_raw_delete_range_request(
     start_key: Vec<u8>,

src/request/plan.rs

@@ -117,11 +117,10 @@ where
     ) -> Result<<Self as Plan>::Result> {
         let shards = current_plan.shards(&pd_client).collect::<Vec<_>>().await;
         debug!("single_plan_handler, shards: {}", shards.len());
-        let mut handles = Vec::new();
+        let mut handles = Vec::with_capacity(shards.len());
         for shard in shards {
             let (shard, region) = shard?;
-            let mut clone = current_plan.clone();
-            clone.apply_shard(shard);
+            let clone = current_plan.clone_then_apply_shard(shard);
             let handle = tokio::spawn(Self::single_shard_handler(
                 pd_client.clone(),
                 clone,

src/request/shard.rs

@@ -48,6 +48,16 @@ pub trait Shardable {
 
     fn apply_shard(&mut self, shard: Self::Shard);
 
+    /// Implementation can skip unnecessary fields clone if fields will be overwritten by `apply_shard`.
+    fn clone_then_apply_shard(&self, shard: Self::Shard) -> Self
+    where
+        Self: Sized + Clone,
+    {
+        let mut cloned = self.clone();
+        cloned.apply_shard(shard);
+        cloned
+    }
+
     fn apply_store(&mut self, store: &RegionStore) -> Result<()>;
 }
 
@@ -103,6 +113,16 @@ impl<Req: KvRequest + Shardable> Shardable for Dispatch<Req> {
         self.request.apply_shard(shard);
     }
 
+    fn clone_then_apply_shard(&self, shard: Self::Shard) -> Self
+    where
+        Self: Sized + Clone,
+    {
+        Dispatch {
+            request: self.request.clone_then_apply_shard(shard),
+            kv_client: self.kv_client.clone(),
+        }
+    }
+
     fn apply_store(&mut self, store: &RegionStore) -> Result<()> {
         self.kv_client = Some(store.client.clone());
         self.request.apply_store(store)

tests/integration_tests.rs

@@ -871,6 +871,53 @@ async fn raw_write_million() -> Result<()> {
     Ok(())
 }
 
+/// Tests raw batch put has a large payload.
+#[tokio::test]
+#[serial]
+async fn raw_large_batch_put() -> Result<()> {
+    const TARGET_SIZE_MB: usize = 100;
+    const KEY_SIZE: usize = 32;
+    const VALUE_SIZE: usize = 1024;
+
+    let pair_size = KEY_SIZE + VALUE_SIZE;
+    let target_size_bytes = TARGET_SIZE_MB * 1024 * 1024;
+    let num_pairs = target_size_bytes / pair_size;
+    let mut pairs = Vec::with_capacity(num_pairs);
+    for i in 0..num_pairs {
+        // Generate key: "bench_key_" + zero-padded number
+        let key = format!("bench_key_{:010}", i);
+
+        // Generate value: repeat pattern to reach VALUE_SIZE
+        let pattern = format!("value_{}", i % 1000);
+        let repeat_count = VALUE_SIZE.div_ceil(pattern.len());
+        let value = pattern.repeat(repeat_count);
+
+        pairs.push(KvPair::from((key, value)));
+    }
+
+    init().await?;
+    let client =
+        RawClient::new_with_config(pd_addrs(), Config::default().with_default_keyspace()).await?;
+
+    client.batch_put(pairs.clone()).await?;
+
+    let keys = pairs.iter().map(|pair| pair.0.clone()).collect::<Vec<_>>();
+    // split into multiple batch_get to avoid response too large error
+    const BATCH_SIZE: usize = 1000;
+    let mut got = Vec::with_capacity(num_pairs);
+    for chunk in keys.chunks(BATCH_SIZE) {
+        let mut partial = client.batch_get(chunk.to_vec()).await?;
+        got.append(&mut partial);
+    }
+    assert_eq!(got, pairs);
+
+    client.batch_delete(keys.clone()).await?;
+    let res = client.batch_get(keys).await?;
+    assert!(res.is_empty());
+
+    Ok(())
+}
+
 /// Tests raw ttl API.
 #[tokio::test]
 #[serial]