warn when shotover doesnt know how to route a request

shotover/src/transforms/kafka/sink_cluster/mod.rs

@@ -19,6 +19,7 @@ use kafka_protocol::messages::fetch_response::LeaderIdAndEpoch as FetchResponseL
 use kafka_protocol::messages::list_offsets_request::ListOffsetsTopic;
 use kafka_protocol::messages::metadata_request::MetadataRequestTopic;
 use kafka_protocol::messages::metadata_response::MetadataResponseBroker;
+use kafka_protocol::messages::offset_for_leader_epoch_request::OffsetForLeaderTopic;
 use kafka_protocol::messages::produce_request::TopicProduceData;
 use kafka_protocol::messages::produce_response::{
     LeaderIdAndEpoch as ProduceResponseLeaderIdAndEpoch, TopicProduceResponse,
@@ -28,9 +29,9 @@ use kafka_protocol::messages::{
     BrokerId, EndTxnRequest, FetchRequest, FetchResponse, FindCoordinatorRequest,
     FindCoordinatorResponse, GroupId, HeartbeatRequest, InitProducerIdRequest, JoinGroupRequest,
     LeaveGroupRequest, ListOffsetsRequest, ListOffsetsResponse, MetadataRequest, MetadataResponse,
-    ProduceRequest, ProduceResponse, RequestHeader, SaslAuthenticateRequest,
-    SaslAuthenticateResponse, SaslHandshakeRequest, SyncGroupRequest, TopicName, TransactionalId,
-    TxnOffsetCommitRequest,
+    OffsetForLeaderEpochRequest, OffsetForLeaderEpochResponse, ProduceRequest, ProduceResponse,
+    RequestHeader, SaslAuthenticateRequest, SaslAuthenticateResponse, SaslHandshakeRequest,
+    SyncGroupRequest, TopicName, TransactionalId, TxnOffsetCommitRequest,
 };
 use kafka_protocol::protocol::StrBytes;
 use kafka_protocol::ResponseError;
@@ -46,7 +47,7 @@ use serde::{Deserialize, Serialize};
 use shotover_node::{ShotoverNode, ShotoverNodeConfig};
 use split::{
     AddPartitionsToTxnRequestSplitAndRouter, ListOffsetsRequestSplitAndRouter,
-    ProduceRequestSplitAndRouter, RequestSplitAndRouter,
+    OffsetForLeaderEpochRequestSplitAndRouter, ProduceRequestSplitAndRouter, RequestSplitAndRouter,
 };
 use std::collections::{HashMap, HashSet, VecDeque};
 use std::hash::Hasher;
@@ -675,6 +676,14 @@ impl KafkaSinkCluster {
                         self.store_topic_names(&mut topic_names, topic.name.clone());
                     }
                 }
+                Some(Frame::Kafka(KafkaFrame::Request {
+                    body: RequestBody::OffsetForLeaderEpoch(body),
+                    ..
+                })) => {
+                    for topic in &body.topics {
+                        self.store_topic_names(&mut topic_names, topic.topic.clone());
+                    }
+                }
                 Some(Frame::Kafka(KafkaFrame::Request {
                     body: RequestBody::Fetch(fetch),
                     ..
@@ -852,6 +861,12 @@ impl KafkaSinkCluster {
                     body: RequestBody::ListOffsets(_),
                     ..
                 })) => self.split_and_route_request::<ListOffsetsRequestSplitAndRouter>(message)?,
+                Some(Frame::Kafka(KafkaFrame::Request {
+                    body: RequestBody::OffsetForLeaderEpoch(_),
+                    ..
+                })) => self.split_and_route_request::<OffsetForLeaderEpochRequestSplitAndRouter>(
+                    message,
+                )?,
 
                 // route to group coordinator
                 Some(Frame::Kafka(KafkaFrame::Request {
@@ -965,7 +980,33 @@ impl KafkaSinkCluster {
                     body: RequestBody::CreateTopics(_),
                     ..
                 })) => self.route_to_controller(message),
-                _ => self.route_to_random_broker(message),
+
+                // route to random broker
+                Some(Frame::Kafka(KafkaFrame::Request {
+                    body:
+                        RequestBody::Metadata(_)
+                        | RequestBody::DescribeConfigs(_)
+                        | RequestBody::AlterConfigs(_)
+                        | RequestBody::CreatePartitions(_)
+                        | RequestBody::DeleteTopics(_)
+                        | RequestBody::CreateAcls(_),
+                    ..
+                })) => self.route_to_random_broker(message),
+
+                // error handling
+                Some(Frame::Kafka(KafkaFrame::Request { header, .. })) => {
+                    let request_type =
+                        format!("{:?}", ApiKey::try_from(header.request_api_key).unwrap());
+                    // remove Key postfix, since its not part of the actual message name which is confusing.
+                    let request_type = request_type.trim_end_matches("Key");
+                    tracing::warn!("Routing for request of type {request_type:?} has not been implemented yet.");
+                    self.route_to_random_broker(message)
+                }
+                Some(_) => unreachable!("Must be a kafka request"),
+                None => {
+                    tracing::warn!("Unable to parse request, routing to a random node");
+                    self.route_to_random_broker(message)
+                }
             }
         }
         Ok(())
@@ -1330,6 +1371,59 @@ impl KafkaSinkCluster {
         result
     }
 
+    /// This method removes all topics from the list offsets request and returns them split up by their destination
+    /// If any topics are unroutable they will have their BrokerId set to -1
+    fn split_offset_for_leader_epoch_request_by_destination(
+        &mut self,
+        body: &mut OffsetForLeaderEpochRequest,
+    ) -> HashMap<BrokerId, Vec<OffsetForLeaderTopic>> {
+        let mut result: HashMap<BrokerId, Vec<OffsetForLeaderTopic>> = Default::default();
+
+        for mut topic in body.topics.drain(..) {
+            let topic_name = &topic.topic;
+            if let Some(topic_meta) = self.topic_by_name.get(topic_name) {
+                for partition in std::mem::take(&mut topic.partitions) {
+                    let partition_index = partition.partition as usize;
+                    let destination = if let Some(partition) =
+                        topic_meta.partitions.get(partition_index)
+                    {
+                        if partition.leader_id == -1 {
+                            tracing::warn!(
+                                "leader_id is unknown for {topic_name:?} at partition index {partition_index}",
+                            );
+                        }
+                        partition.leader_id
+                    } else {
+                        let partition_len = topic_meta.partitions.len();
+                        tracing::warn!("no known partition for {topic_name:?} at partition index {partition_index} out of {partition_len} partitions, routing request to a random broker so that a NOT_LEADER_OR_FOLLOWER or similar error is returned to the client");
+                        BrokerId(-1)
+                    };
+                    tracing::debug!(
+                        "Routing OffsetForLeaderEpoch request portion of partition {partition_index} in {topic_name:?} to broker {}",
+                        destination.0
+                    );
+                    let dest_topics = result.entry(destination).or_default();
+                    if let Some(dest_topic) =
+                        dest_topics.iter_mut().find(|x| x.topic == topic.topic)
+                    {
+                        dest_topic.partitions.push(partition);
+                    } else {
+                        let mut topic = topic.clone();
+                        topic.partitions.push(partition);
+                        dest_topics.push(topic);
+                    }
+                }
+            } else {
+                tracing::warn!("no known partition replica for {topic_name:?}, routing message to a random broker so that a NOT_LEADER_OR_FOLLOWER or similar error is returned to the client");
+                let destination = BrokerId(-1);
+                let dest_topics = result.entry(destination).or_default();
+                dest_topics.push(topic);
+            }
+        }
+
+        result
+    }
+
     /// This method removes all transactions from the AddPartitionsToTxn request and returns them split up by their destination
     /// If any topics are unroutable they will have their BrokerId set to -1
     fn split_add_partition_to_txn_request_by_destination(
@@ -1808,6 +1902,10 @@ impl KafkaSinkCluster {
                 body: ResponseBody::ListOffsets(base),
                 ..
             })) => Self::combine_list_offsets_responses(base, drain)?,
+            Some(Frame::Kafka(KafkaFrame::Response {
+                body: ResponseBody::OffsetForLeaderEpoch(base),
+                ..
+            })) => Self::combine_offset_for_leader_epoch_responses(base, drain)?,
             Some(Frame::Kafka(KafkaFrame::Response {
                 body: ResponseBody::Produce(base),
                 ..
@@ -1903,7 +2001,46 @@ impl KafkaSinkCluster {
                 }
             } else {
                 return Err(anyhow!(
-                    "Combining ListOffests responses but received another message type"
+                    "Combining ListOffsets responses but received another message type"
+                ));
+            }
+        }
+
+        Ok(())
+    }
+
+    fn combine_offset_for_leader_epoch_responses(
+        base_list_offsets: &mut OffsetForLeaderEpochResponse,
+        drain: impl Iterator<Item = Message>,
+    ) -> Result<()> {
+        for mut next in drain {
+            if let Some(Frame::Kafka(KafkaFrame::Response {
+                body: ResponseBody::OffsetForLeaderEpoch(next_body),
+                ..
+            })) = next.frame()
+            {
+                for next_topic in std::mem::take(&mut next_body.topics) {
+                    if let Some(base_topic) = base_list_offsets
+                        .topics
+                        .iter_mut()
+                        .find(|topic| topic.topic == next_topic.topic)
+                    {
+                        for next_partition in &next_topic.partitions {
+                            for base_partition in &base_topic.partitions {
+                                if next_partition.partition == base_partition.partition {
+                                    tracing::warn!("Duplicate partition indexes in combined OffsetForLeaderEpoch response, if this ever occurs we should investigate the repercussions")
+                                }
+                            }
+                        }
+                        // A partition can only be contained in one response so there is no risk of duplicating partitions
+                        base_topic.partitions.extend(next_topic.partitions)
+                    } else {
+                        base_list_offsets.topics.push(next_topic);
+                    }
+                }
+            } else {
+                return Err(anyhow!(
+                    "Combining OffsetForLeaderEpoch responses but received another message type"
                 ));
             }
         }
@@ -2132,6 +2269,25 @@ impl KafkaSinkCluster {
                     }
                 }
             }
+            Some(Frame::Kafka(KafkaFrame::Response {
+                body: ResponseBody::OffsetForLeaderEpoch(body),
+                ..
+            })) => {
+                for topic in &mut body.topics {
+                    for partition in &mut topic.partitions {
+                        if let Some(ResponseError::NotLeaderOrFollower) =
+                            ResponseError::try_from_code(partition.error_code)
+                        {
+                            self.topic_by_name.remove(&topic.topic);
+                            tracing::info!(
+                                "OffsetForLeaderEpoch response included error NOT_LEADER_OR_FOLLOWER and so cleared metadata for topic {:?}",
+                                topic.topic,
+                            );
+                            break;
+                        }
+                    }
+                }
+            }
             Some(Frame::Kafka(KafkaFrame::Response {
                 body: ResponseBody::Heartbeat(heartbeat),
                 ..

shotover/src/transforms/kafka/sink_cluster/split.rs

@@ -8,8 +8,9 @@ use crate::{
 };
 use kafka_protocol::messages::{
     add_partitions_to_txn_request::AddPartitionsToTxnTransaction,
-    list_offsets_request::ListOffsetsTopic, produce_request::TopicProduceData,
-    AddPartitionsToTxnRequest, BrokerId, ListOffsetsRequest, ProduceRequest, TopicName,
+    list_offsets_request::ListOffsetsTopic, offset_for_leader_epoch_request::OffsetForLeaderTopic,
+    produce_request::TopicProduceData, AddPartitionsToTxnRequest, BrokerId, ListOffsetsRequest,
+    OffsetForLeaderEpochRequest, ProduceRequest, TopicName,
 };
 use std::collections::HashMap;
 
@@ -107,3 +108,31 @@ impl RequestSplitAndRouter for ListOffsetsRequestSplitAndRouter {
         request.topics = item;
     }
 }
+
+pub struct OffsetForLeaderEpochRequestSplitAndRouter;
+
+impl RequestSplitAndRouter for OffsetForLeaderEpochRequestSplitAndRouter {
+    type Request = OffsetForLeaderEpochRequest;
+    type SubRequests = Vec<OffsetForLeaderTopic>;
+
+    fn split_by_destination(
+        transform: &mut KafkaSinkCluster,
+        request: &mut Self::Request,
+    ) -> HashMap<BrokerId, Self::SubRequests> {
+        transform.split_offset_for_leader_epoch_request_by_destination(request)
+    }
+
+    fn get_request_frame(request: &mut Message) -> Option<&mut Self::Request> {
+        match request.frame() {
+            Some(Frame::Kafka(KafkaFrame::Request {
+                body: RequestBody::OffsetForLeaderEpoch(request),
+                ..
+            })) => Some(request),
+            _ => None,
+        }
+    }
+
+    fn reassemble(request: &mut Self::Request, item: Self::SubRequests) {
+        request.topics = item;
+    }
+}