feat(stream): create cdc table reader and source data stream with ret…

…ry (#19467)

src/compute/tests/cdc_tests.rs

@@ -32,10 +32,8 @@ use risingwave_common::catalog::{ColumnDesc, ColumnId, ConflictBehavior, Field,
 use risingwave_common::types::{Datum, JsonbVal};
 use risingwave_common::util::epoch::{test_epoch, EpochExt};
 use risingwave_common::util::sort_util::{ColumnOrder, OrderType};
-use risingwave_connector::source::cdc::external::mock_external_table::MockExternalTableReader;
-use risingwave_connector::source::cdc::external::mysql::MySqlOffset;
 use risingwave_connector::source::cdc::external::{
-    DebeziumOffset, DebeziumSourceOffset, ExternalTableReaderImpl, SchemaTableName,
+    CdcTableType, DebeziumOffset, DebeziumSourceOffset, ExternalTableConfig, SchemaTableName,
 };
 use risingwave_connector::source::cdc::DebeziumCdcSplit;
 use risingwave_connector::source::SplitImpl;
@@ -160,19 +158,6 @@ async fn test_cdc_backfill() -> StreamResult<()> {
         MockOffsetGenExecutor::new(source).boxed(),
     );
 
-    let binlog_file = String::from("1.binlog");
-    // mock binlog watermarks for backfill
-    // initial low watermark: 1.binlog, pos=2 and expected behaviors:
-    // - ignore events before (1.binlog, pos=2);
-    // - apply events in the range of (1.binlog, pos=2, 1.binlog, pos=4) to the snapshot
-    let binlog_watermarks = vec![
-        MySqlOffset::new(binlog_file.clone(), 2), // binlog low watermark
-        MySqlOffset::new(binlog_file.clone(), 4),
-        MySqlOffset::new(binlog_file.clone(), 6),
-        MySqlOffset::new(binlog_file.clone(), 8),
-        MySqlOffset::new(binlog_file.clone(), 10),
-    ];
-
     let table_name = SchemaTableName {
         schema_name: "public".to_string(),
         table_name: "mock_table".to_string(),
@@ -183,11 +168,14 @@ async fn test_cdc_backfill() -> StreamResult<()> {
     ]);
     let table_pk_indices = vec![0];
     let table_pk_order_types = vec![OrderType::ascending()];
+    let config = ExternalTableConfig::default();
+
     let external_table = ExternalStorageTable::new(
         TableId::new(1234),
         table_name,
         "mydb".to_string(),
-        ExternalTableReaderImpl::Mock(MockExternalTableReader::new(binlog_watermarks)),
+        config,
+        CdcTableType::Mock,
         table_schema.clone(),
         table_pk_order_types,
         table_pk_indices.clone(),

src/connector/src/source/cdc/external/mock_external_table.rs

@@ -31,7 +31,19 @@ pub struct MockExternalTableReader {
 }
 
 impl MockExternalTableReader {
-    pub fn new(binlog_watermarks: Vec<MySqlOffset>) -> Self {
+    pub fn new() -> Self {
+        let binlog_file = String::from("1.binlog");
+        // mock binlog watermarks for backfill
+        // initial low watermark: 1.binlog, pos=2 and expected behaviors:
+        // - ignore events before (1.binlog, pos=2);
+        // - apply events in the range of (1.binlog, pos=2, 1.binlog, pos=4) to the snapshot
+        let binlog_watermarks = vec![
+            MySqlOffset::new(binlog_file.clone(), 2), // binlog low watermark
+            MySqlOffset::new(binlog_file.clone(), 4),
+            MySqlOffset::new(binlog_file.clone(), 6),
+            MySqlOffset::new(binlog_file.clone(), 8),
+            MySqlOffset::new(binlog_file.clone(), 10),
+        ];
         Self {
             binlog_watermarks,
             snapshot_cnt: AtomicUsize::new(0),

src/connector/src/source/cdc/external/mod.rs

@@ -45,9 +45,10 @@ use crate::source::cdc::external::sql_server::{
 use crate::source::cdc::CdcSourceType;
 use crate::WithPropertiesExt;
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum CdcTableType {
     Undefined,
+    Mock,
     MySql,
     Postgres,
     SqlServer,
@@ -97,6 +98,7 @@ impl CdcTableType {
             Self::SqlServer => Ok(ExternalTableReaderImpl::SqlServer(
                 SqlServerExternalTableReader::new(config, schema, pk_indices).await?,
             )),
+            Self::Mock => Ok(ExternalTableReaderImpl::Mock(MockExternalTableReader::new())),
             _ => bail!("invalid external table type: {:?}", *self),
         }
     }
@@ -214,7 +216,7 @@ pub enum ExternalTableReaderImpl {
     Mock(MockExternalTableReader),
 }
 
-#[derive(Debug, Clone, Deserialize)]
+#[derive(Debug, Default, Clone, Deserialize)]
 pub struct ExternalTableConfig {
     pub connector: String,
 

src/stream/src/executor/backfill/cdc/cdc_backfill.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::future::Future;
 use std::pin::Pin;
 
 use either::Either;
@@ -27,9 +28,11 @@ use risingwave_connector::parser::{
     ByteStreamSourceParser, DebeziumParser, DebeziumProps, EncodingProperties, JsonProperties,
     ProtocolProperties, SourceStreamChunkBuilder, SpecificParserConfig,
 };
-use risingwave_connector::source::cdc::external::CdcOffset;
+use risingwave_connector::source::cdc::external::{CdcOffset, ExternalTableReaderImpl};
 use risingwave_connector::source::{SourceColumnDesc, SourceContext};
 use rw_futures_util::pausable;
+use thiserror_ext::AsReport;
+use tracing::Instrument;
 
 use crate::executor::backfill::cdc::state::CdcBackfillState;
 use crate::executor::backfill::cdc::upstream_table::external::ExternalStorageTable;
@@ -42,6 +45,7 @@ use crate::executor::backfill::utils::{
 use crate::executor::backfill::CdcScanOptions;
 use crate::executor::monitor::CdcBackfillMetrics;
 use crate::executor::prelude::*;
+use crate::executor::source::get_infinite_backoff_strategy;
 use crate::executor::UpdateMutation;
 use crate::task::CreateMviewProgressReporter;
 
@@ -140,7 +144,6 @@ impl<S: StateStore> CdcBackfillExecutor<S> {
         let upstream_table_name = self.external_table.qualified_table_name();
         let schema_table_name = self.external_table.schema_table_name().clone();
         let external_database_name = self.external_table.database_name().to_owned();
-        let upstream_table_reader = UpstreamTableReader::new(self.external_table);
 
         let additional_columns = self
             .output_columns
@@ -168,29 +171,85 @@ impl<S: StateStore> CdcBackfillExecutor<S> {
         // if not, we should bypass the backfill directly.
         let mut state_impl = self.state_impl;
 
-        let mut upstream = transform_upstream(upstream, &self.output_columns)
-            .boxed()
-            .peekable();
-
         state_impl.init_epoch(first_barrier_epoch).await?;
 
         // restore backfill state
         let state = state_impl.restore_state().await?;
         current_pk_pos = state.current_pk_pos.clone();
 
-        let to_backfill = !self.options.disable_backfill && !state.is_finished;
+        let need_backfill = !self.options.disable_backfill && !state.is_finished;
 
         // Keep track of rows from the snapshot.
         let mut total_snapshot_row_count = state.row_count as u64;
 
+        // After init the state table and forward the initial barrier to downstream,
+        // we now try to create the table reader with retry.
+        // If backfill hasn't finished, we can ignore upstream cdc events before we create the table reader;
+        // If backfill is finished, we should forward the upstream cdc events to downstream.
+        let mut table_reader: Option<ExternalTableReaderImpl> = None;
+        let external_table = self.external_table.clone();
+        let mut future = Box::pin(async move {
+            let backoff = get_infinite_backoff_strategy();
+            tokio_retry::Retry::spawn(backoff, || async {
+                match external_table.create_table_reader().await {
+                    Ok(reader) => Ok(reader),
+                    Err(e) => {
+                        tracing::warn!(error = %e.as_report(), "failed to create cdc table reader, retrying...");
+                        Err(e)
+                    }
+                }
+            })
+            .instrument(tracing::info_span!("create_cdc_table_reader_with_retry"))
+            .await
+            .expect("Retry create cdc table reader until success.")
+        });
+        loop {
+            if let Some(msg) =
+                build_reader_and_poll_upstream(&mut upstream, &mut table_reader, &mut future)
+                    .await?
+            {
+                match msg {
+                    Message::Barrier(barrier) => {
+                        // commit state to bump the epoch of state table
+                        state_impl.commit_state(barrier.epoch).await?;
+                        yield Message::Barrier(barrier);
+                    }
+                    Message::Chunk(chunk) => {
+                        if need_backfill {
+                            // ignore chunk if we need backfill, since we can read the data from the snapshot
+                        } else {
+                            // forward the chunk to downstream
+                            yield Message::Chunk(chunk);
+                        }
+                    }
+                    Message::Watermark(_) => {
+                        // ignore watermark
+                    }
+                }
+            } else {
+                assert!(table_reader.is_some(), "table reader must created");
+                tracing::info!(
+                    table_id,
+                    upstream_table_name,
+                    "table reader created successfully"
+                );
+                break;
+            }
+        }
+
+        let upstream_table_reader = UpstreamTableReader::new(
+            self.external_table.clone(),
+            table_reader.expect("table reader must created"),
+        );
+
+        let mut upstream = transform_upstream(upstream, &self.output_columns)
+            .boxed()
+            .peekable();
         let mut last_binlog_offset: Option<CdcOffset> = state
             .last_cdc_offset
             .map_or(upstream_table_reader.current_cdc_offset().await?, Some);
 
-        let offset_parse_func = upstream_table_reader
-            .inner()
-            .table_reader()
-            .get_cdc_offset_parser();
+        let offset_parse_func = upstream_table_reader.reader.get_cdc_offset_parser();
         let mut consumed_binlog_offset: Option<CdcOffset> = None;
 
         tracing::info!(
@@ -227,7 +286,7 @@ impl<S: StateStore> CdcBackfillExecutor<S> {
         // finished.
         //
         // Once the backfill loop ends, we forward the upstream directly to the downstream.
-        if to_backfill {
+        if need_backfill {
             // drive the upstream changelog first to ensure we can receive timely changelog event,
             // otherwise the upstream changelog may be blocked by the snapshot read stream
             let _ = Pin::new(&mut upstream).peek().await;
@@ -702,6 +761,26 @@ impl<S: StateStore> CdcBackfillExecutor<S> {
     }
 }
 
+async fn build_reader_and_poll_upstream(
+    upstream: &mut BoxedMessageStream,
+    table_reader: &mut Option<ExternalTableReaderImpl>,
+    future: &mut Pin<Box<impl Future<Output = ExternalTableReaderImpl>>>,
+) -> StreamExecutorResult<Option<Message>> {
+    if table_reader.is_some() {
+        return Ok(None);
+    }
+    tokio::select! {
+        biased;
+        reader = &mut *future => {
+            *table_reader = Some(reader);
+            Ok(None)
+        }
+        msg = upstream.next() => {
+            msg.transpose()
+        }
+    }
+}
+
 #[try_stream(ok = Message, error = StreamExecutorError)]
 pub async fn transform_upstream(upstream: BoxedMessageStream, output_columns: &[ColumnDesc]) {
     let props = SpecificParserConfig {

src/stream/src/executor/backfill/cdc/upstream_table/external.rs

@@ -14,9 +14,14 @@
 
 use risingwave_common::catalog::{Schema, TableId};
 use risingwave_common::util::sort_util::OrderType;
-use risingwave_connector::source::cdc::external::{ExternalTableReaderImpl, SchemaTableName};
+use risingwave_connector::error::ConnectorResult;
+use risingwave_connector::source::cdc::external::{
+    CdcOffset, CdcTableType, ExternalTableConfig, ExternalTableReader, ExternalTableReaderImpl,
+    SchemaTableName,
+};
 
 /// This struct represents an external table to be read during backfill
+#[derive(Debug, Clone)]
 pub struct ExternalStorageTable {
     /// Id for this table.
     table_id: TableId,
@@ -28,7 +33,9 @@ pub struct ExternalStorageTable {
 
     database_name: String,
 
-    table_reader: ExternalTableReaderImpl,
+    config: ExternalTableConfig,
+
+    table_type: CdcTableType,
 
     /// The schema of the output columns, i.e., this table VIEWED BY some executor like
     /// `RowSeqScanExecutor`.
@@ -43,14 +50,16 @@ pub struct ExternalStorageTable {
 }
 
 impl ExternalStorageTable {
+    #[allow(clippy::too_many_arguments)]
     pub fn new(
         table_id: TableId,
         SchemaTableName {
             table_name,
             schema_name,
         }: SchemaTableName,
         database_name: String,
-        table_reader: ExternalTableReaderImpl,
+        config: ExternalTableConfig,
+        table_type: CdcTableType,
         schema: Schema,
         pk_order_types: Vec<OrderType>,
         pk_indices: Vec<usize>,
@@ -60,7 +69,8 @@ impl ExternalStorageTable {
             table_name,
             schema_name,
             database_name,
-            table_reader,
+            config,
+            table_type,
             schema,
             pk_order_types,
             pk_indices,
@@ -90,8 +100,14 @@ impl ExternalStorageTable {
         }
     }
 
-    pub fn table_reader(&self) -> &ExternalTableReaderImpl {
-        &self.table_reader
+    pub async fn create_table_reader(&self) -> ConnectorResult<ExternalTableReaderImpl> {
+        self.table_type
+            .create_table_reader(
+                self.config.clone(),
+                self.schema.clone(),
+                self.pk_indices.clone(),
+            )
+            .await
     }
 
     pub fn qualified_table_name(&self) -> String {
@@ -101,4 +117,12 @@ impl ExternalStorageTable {
     pub fn database_name(&self) -> &str {
         self.database_name.as_str()
     }
+
+    pub async fn current_cdc_offset(
+        &self,
+        table_reader: &ExternalTableReaderImpl,
+    ) -> ConnectorResult<Option<CdcOffset>> {
+        let binlog = table_reader.current_cdc_offset().await?;
+        Ok(Some(binlog))
+    }
 }