feat(connector): partition source reader batch_size by rate_limit

e2e_test/streaming/rate_limit/upstream_amplification.slt

@@ -0,0 +1,44 @@
+# This test will test that barrier latency does not spike
+# when there's rate limit on source.
+# The upstream side should backpressure the source reader,
+# but still allow barriers to flow through.
+
+statement ok
+SET STREAMING_PARALLELISM=2;
+
+statement ok
+SET STREAMING_RATE_LIMIT=1;
+
+statement ok
+CREATE TABLE source_table (i1 int)
+WITH (
+    connector = 'datagen',
+    fields.i1.start = '1',
+    fields.i1.end = '5',
+    datagen.rows.per.second = '10000'
+) FORMAT PLAIN ENCODE JSON;
+
+statement ok
+CREATE SINK sink AS
+    SELECT x.i1 as i1 FROM source_table x
+        JOIN source_table s1 ON x.i1 = s1.i1
+            JOIN source_table s2 ON x.i1 = s2.i1
+                JOIN source_table s3 ON x.i1 = s3.i1
+    WITH (connector = 'blackhole');
+
+# The following sequence of FLUSH should be fast, since barrier should be able to bypass sink.
+# Otherwise, these FLUSH will take a long time to complete, and trigger timeout.
+statement ok
+flush;
+
+statement ok
+flush;
+
+statement ok
+flush;
+
+statement ok
+drop sink sink;
+
+statement ok
+drop table source_table;

src/batch/src/executor/source.rs

@@ -87,6 +87,7 @@ impl BoxedExecutorBuilder for SourceExecutor {
         };
         let source_ctrl_opts = SourceCtrlOpts {
             chunk_size: source.context().get_config().developer.chunk_size,
+            rate_limit: None,
         };
 
         let column_ids: Vec<_> = source_node

src/connector/src/parser/mod.rs

@@ -56,7 +56,7 @@ use crate::schema::schema_registry::SchemaRegistryAuth;
 use crate::source::monitor::GLOBAL_SOURCE_METRICS;
 use crate::source::{
     extract_source_struct, BoxSourceStream, ChunkSourceStream, SourceColumnDesc, SourceColumnType,
-    SourceContext, SourceContextRef, SourceEncode, SourceFormat, SourceMeta,
+    SourceContext, SourceContextRef, SourceEncode, SourceFormat, SourceMessage, SourceMeta,
 };
 
 pub mod additional_columns;
@@ -556,6 +556,21 @@ pub trait ByteStreamSourceParser: Send + Debug + Sized + 'static {
     }
 }
 
+#[try_stream(ok = Vec<SourceMessage>, error = anyhow::Error)]
+async fn ensure_largest_at_rate_limit(stream: BoxSourceStream, rate_limit: u32) {
+    #[for_await]
+    for batch in stream {
+        let mut batch = batch?;
+        let mut start = 0;
+        let end = batch.len();
+        while start < end {
+            let next = std::cmp::min(start + rate_limit as usize, end);
+            yield std::mem::take(&mut batch[start..next].as_mut()).to_vec();
+            start = next;
+        }
+    }
+}
+
 #[easy_ext::ext(SourceParserIntoStreamExt)]
 impl<P: ByteStreamSourceParser> P {
     /// Parse a data stream of one source split into a stream of [`StreamChunk`].
@@ -568,9 +583,15 @@ impl<P: ByteStreamSourceParser> P {
     ///
     /// A [`ChunkSourceStream`] which is a stream of parsed messages.
     pub fn into_stream(self, data_stream: BoxSourceStream) -> impl ChunkSourceStream {
-        // Enable tracing to provide more information for parsing failures.
         let source_info = self.source_ctx().source_info.clone();
 
+        // Ensure chunk size is smaller than rate limit
+        let data_stream = if let Some(rate_limit) = &self.source_ctx().source_ctrl_opts.rate_limit {
+            Box::pin(ensure_largest_at_rate_limit(data_stream, *rate_limit))
+        } else {
+            data_stream
+        };
+
         // The parser stream will be long-lived. We use `instrument_with` here to create
         // a new span for the polling of each chunk.
         into_chunk_stream(self, data_stream).instrument_with(move || {

src/connector/src/source/base.rs

@@ -133,12 +133,15 @@ pub struct SourceCtrlOpts {
     // comes from developer::stream_chunk_size in stream scenario and developer::batch_chunk_size
     // in batch scenario
     pub chunk_size: usize,
+    /// Rate limit of source
+    pub rate_limit: Option<u32>,
 }
 
 impl Default for SourceCtrlOpts {
     fn default() -> Self {
         Self {
             chunk_size: MAX_CHUNK_SIZE,
+            rate_limit: None,
         }
     }
 }

src/stream/src/from_proto/source/fs_fetch.rs

@@ -61,6 +61,7 @@ impl ExecutorBuilder for FsFetchExecutorBuilder {
         );
         let source_ctrl_opts = SourceCtrlOpts {
             chunk_size: params.env.config().developer.chunk_size,
+            rate_limit: source.rate_limit.map(|x| x as _),
         };
 
         let source_column_ids: Vec<_> = source_desc_builder

src/stream/src/from_proto/source/trad_source.rs

@@ -157,6 +157,7 @@ impl ExecutorBuilder for SourceExecutorBuilder {
 
                 let source_ctrl_opts = SourceCtrlOpts {
                     chunk_size: params.env.config().developer.chunk_size,
+                    rate_limit: source.rate_limit.map(|x| x as _),
                 };
 
                 let source_column_ids: Vec<_> = source_desc_builder