feat(interactive): Impl kafka wal writer and wal paresr

.github/workflows/interactive.yml

@@ -367,6 +367,27 @@ jobs:
         export ENGINE_TYPE=hiactor
         bash hqps_adhoc_test.sh ${INTERACTIVE_WORKSPACE} graph_algo RBO
 
+    - name: Run kafka wal test
+      env:
+        GS_TEST_DIR: ${{ github.workspace }}/gstest
+      run: |
+        cd ${GITHUB_WORKSPACE}/flex/build
+        cmake .. -DBUILD_KAFKA_WAL_WRITER_PARSER=ON && make -j$(nproc)
+        wget https://dlcdn.apache.org/kafka/3.9.0/kafka_2.13-3.9.0.tgz
+        tar -zxf kafka_2.13-3.9.0.tgz
+        cd kafka_2.13-3.9.0
+        KAFKA_CLUSTER_ID="$(bin/kafka-storage.sh random-uuid)"
+        bin/kafka-storage.sh format --standalone -t $KAFKA_CLUSTER_ID -c config/kraft/reconfig-server.properties
+        bin/kafka-server-start.sh config/kraft/reconfig-server.properties &
+
+        bin/kafka-topics.sh --create --topic kafka-test --bootstrap-server localhost:9092
+        ../tests/hqps/kafka_test localhost:9092 kafka-test
+        bin/kafka-topics.sh --delete --topic kafka-test --bootstrap-server localhost:9092
+        bin/kafka-topics.sh --create --topic kafka-test --bootstrap-server localhost:9092
+        ../tests/hqps/kafka_wal_ingester_test .. localhost:9092 kafka-test
+        bin/kafka-topics.sh --delete --topic kafka-test --bootstrap-server localhost:9092
+        ps aux | grep kafka | grep -v grep | awk '{print $2}' | xargs kill -9
+
     - name: Run Gremlin test on modern graph
       env:
         GS_TEST_DIR: ${{ github.workspace }}/gstest

docs/flex/interactive/development/dev_and_test.md

@@ -262,3 +262,40 @@ In Interactive's execution engine, transactions such as `ReadTransaction`, `Upda
 2. If a transaction returns `false` during the `commit()` process, the error occurred prior to applying the WAL to the graph data. This type of failure could arise during the construction of the WAL or during its writing phase.
 
 3. It is important to note that errors can still occur when replaying the WAL to the graph database. Replaying might fail due to limitations in resources or due to unforeseen bugs. **However,** any errors encountered during this stage will be handled via exceptions or may result in process failure. Currently, there is no established mechanism to handle such failures. Future improvements should focus on implementing failover strategies, potentially allowing the GraphDB to continue replaying the WAL until it succeeds.
+
+## Persisting WAL to kafka
+
+Kafka-based WAL storages is also provided. Follows [kafka-quick-start](https://kafka.apache.org/quickstart).
+
+### Install kafka
+
+```bash
+wget https://dlcdn.apache.org/kafka/3.9.0/kafka_2.13-3.9.0.tgz
+tar -zxf kafka_2.13-3.9.0.tgz
+cd kafka_2.13-3.9.0
+```
+
+### kafka with kraft
+
+```bash
+KAFKA_CLUSTER_ID="$(bin/kafka-storage.sh random-uuid)"
+bin/kafka-storage.sh format --standalone -t $KAFKA_CLUSTER_ID -c config/kraft/reconfig-server.properties
+bin/kafka-server-start.sh config/kraft/reconfig-server.properties
+```
+
+### Create topic
+
+```bash
+bin/kafka-topics.sh --create --topic kafka-test --bootstrap-server localhost:9092
+# describe the topic
+bin/kafka-topics.sh --describe --topic kafka-test --bootstrap-server localhost:9092
+```
+
+### Test KafkaWalWriter and KafkaWalParser
+
+```bash
+cd flex && mkdir build
+cd build && cmake .. -DBUILD_TEST=ON && make -j
+./tests/hqps/kafka_test localhost:902 kafka-test
+# run the kafka tst
+```

flex/CMakeLists.txt

@@ -17,6 +17,8 @@ option(USE_PTHASH "Whether to use pthash" OFF)
 option(OPTIMIZE_FOR_HOST "Whether to optimize on host" ON) # Whether to build optimized code on host
 option(USE_STATIC_ARROW "Whether to use static arrow" OFF) # Whether to link arrow statically, default is OFF
 option(BUILD_WITH_OTEL "Whether to build with opentelemetry-cpp" OFF) # Whether to build with opentelemetry-cpp, default is OFF
+
+option(BUILD_KAFKA_WAL_WRITER_PARSER "Whether to build kafka wal writer and wal parser" OFF) # Whether to build kafka wal writer and wal parser, default is OFF
 option(BUILD_WITH_OSS "Whether to build with oss support" OFF) # Whether to build with oss support, default is OFF
 
 #print options
@@ -129,6 +131,21 @@ if (NOT yaml-cpp_FOUND)
     message(FATAL_ERROR "yaml-cpp not found, please install the yaml-cpp library")
 endif ()
 
+#find CppKafka-------------------------------------------------------------------
+if (BUILD_KAFKA_WAL_WRITER_PARSER)
+    find_package(CppKafka)
+    if (NOT CppKafka_FOUND)
+        message(FATAL_ERROR "cppkafka not found, please install cppkafka library")
+    else()
+        include_directories(SYSTEM ${CppKafka_INCLUDE_DIRS})
+        message(STATUS "cpp kafka include dir: ${CppKafka_INCLUDE_DIRS}")
+        set(CppKafka_LIBRARIES CppKafka::cppkafka)
+        add_definitions(-DBUILD_KAFKA_WAL_WRITER_PARSER)
+        message(STATUS "cppkafka found")
+    endif ()
+endif()
+
+
 #find boost----------------------------------------------------------------------
 find_package(Boost REQUIRED COMPONENTS system filesystem
              # required by folly

flex/engines/graph_db/CMakeLists.txt

@@ -4,11 +4,19 @@ file(GLOB_RECURSE GRAPH_DB_SRC_FILES "${CMAKE_CURRENT_SOURCE_DIR}/app/*.cc"
                                      "${CMAKE_CURRENT_SOURCE_DIR}/database/wal/*.cc"
                                      "${CMAKE_CURRENT_SOURCE_DIR}/app/builtin/*.cc")
 
+if (NOT BUILD_KAFKA_WAL_WRITER_PARSER)
+        list(REMOVE_ITEM GRAPH_DB_SRC_FILES "${CMAKE_CURRENT_SOURCE_DIR}/database/wal/kafka_wal_writer.cc"
+                                            "${CMAKE_CURRENT_SOURCE_DIR}/database/wal/kafka_wal_parser.cc")   
+endif()
+
 add_library(flex_graph_db SHARED ${GRAPH_DB_SRC_FILES})
 
 target_include_directories(flex_graph_db PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>)
 target_link_libraries(flex_graph_db flex_rt_mutable_graph ${LIBGRAPELITE_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
 target_link_libraries(flex_graph_db runtime_execute)
+if (BUILD_KAFKA_WAL_WRITER_PARSER)
+        target_link_libraries(flex_graph_db ${CppKafka_LIBRARIES})
+endif()
 install_flex_target(flex_graph_db)
 
 install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/database/graph_db.h

flex/engines/graph_db/app/kafka_wal_ingester_app.cc

@@ -0,0 +1,122 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed 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.
+ */
+
+#include "flex/engines/graph_db/app/kafka_wal_ingester_app.h"
+#include "cppkafka/cppkafka.h"
+#include "flex/engines/graph_db/database/graph_db.h"
+#include "flex/engines/graph_db/database/wal/kafka_wal_parser.h"
+
+namespace gs {
+#ifdef BUILD_KAFKA_WAL_WRITER_PARSER
+
+class KafkaWalConsumer {
+ public:
+  struct CustomComparator {
+    inline bool operator()(const std::string& lhs, const std::string& rhs) {
+      const WalHeader* header1 = reinterpret_cast<const WalHeader*>(lhs.data());
+      const WalHeader* header2 = reinterpret_cast<const WalHeader*>(rhs.data());
+      return header1->timestamp > header2->timestamp;
+    }
+  };
+  static constexpr const std::chrono::milliseconds POLL_TIMEOUT =
+      std::chrono::milliseconds(100);
+
+  // always track all partitions and from begining
+  KafkaWalConsumer(cppkafka::Configuration config,
+                   const std::string& topic_name, int32_t thread_num) {
+    auto topic_partitions = get_all_topic_partitions(config, topic_name, false);
+    consumers_.reserve(topic_partitions.size());
+    for (size_t i = 0; i < topic_partitions.size(); ++i) {
+      consumers_.emplace_back(std::make_unique<cppkafka::Consumer>(config));
+      consumers_.back()->assign({topic_partitions[i]});
+    }
+  }
+
+  std::string poll() {
+    for (auto& consumer : consumers_) {
+      auto msg = consumer->poll();
+      if (msg) {
+        if (msg.get_error()) {
+          if (!msg.is_eof()) {
+            LOG(INFO) << "[+] Received error notification: " << msg.get_error();
+          }
+        } else {
+          std::string payload = msg.get_payload();
+          message_queue_.push(payload);
+          consumer->commit(msg);
+        }
+      }
+    }
+    if (message_queue_.empty()) {
+      return "";
+    }
+    std::string payload = message_queue_.top();
+    message_queue_.pop();
+    return payload;
+  }
+
+ private:
+  std::vector<std::unique_ptr<cppkafka::Consumer>> consumers_;
+  std::priority_queue<std::string, std::vector<std::string>, CustomComparator>
+      message_queue_;
+};
+
+bool KafkaWalIngesterApp::Query(GraphDBSession& graph, Decoder& input,
+                                Encoder& output) {
+  cppkafka::Configuration config;
+  std::string topic_name;
+  while (!input.empty()) {
+    auto key = input.get_string();
+    auto value = input.get_string();
+    if (key == "topic_name") {
+      topic_name = value;
+    } else {
+      config.set(std::string(key), std::string(value));
+    }
+  }
+  LOG(INFO) << "Kafka brokers: " << config.get("metadata.broker.list");
+
+  gs::KafkaWalConsumer consumer(config, topic_name, 1);
+  // TODO: how to make it stop
+  while (graph.db().kafka_wal_ingester_state()) {
+    auto res = consumer.poll();
+    if (res.empty()) {
+      std::this_thread::sleep_for(gs::KafkaWalConsumer::POLL_TIMEOUT);
+      continue;
+    }
+    auto header = reinterpret_cast<const WalHeader*>(res.data());
+    if (header->type == 0) {
+      auto txn = graph.GetInsertTransaction();
+      txn.IngestWal(graph.graph(), txn.timestamp(),
+                    const_cast<char*>(res.data()) + sizeof(WalHeader),
+                    header->length, txn.allocator());
+      txn.Commit();
+    } else if (header->type == 1) {
+      auto txn = graph.GetUpdateTransaction();
+      txn.IngestWal(graph.graph(), graph.db().work_dir(), txn.timestamp(),
+                    const_cast<char*>(res.data()) + sizeof(WalHeader),
+                    header->length, txn.allocator());
+      txn.Commit();
+    } else {
+      LOG(ERROR) << "Unknown wal type: " << header->type;
+    }
+  }
+  return true;
+}
+AppWrapper KafkaWalIngesterAppFactory::CreateApp(const GraphDB& db) {
+  return AppWrapper(new KafkaWalIngesterApp(), NULL);
+}
+#endif
+}  // namespace gs

flex/engines/graph_db/app/kafka_wal_ingester_app.h

@@ -0,0 +1,45 @@
+/** Copyright 2020 Alibaba Group Holding Limited.
+ *
+ * Licensed 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.
+ */
+
+#ifndef ENGINES_KAFKA_WAL_INGESTER_APP_H_
+#define ENGINES_KAFKA_WAL_INGESTER_APP_H_
+
+#include "flex/engines/graph_db/app/app_base.h"
+#include "flex/engines/graph_db/database/graph_db_session.h"
+
+namespace gs {
+#ifdef BUILD_KAFKA_WAL_WRITER_PARSER
+// Ingest wal from kafka
+class KafkaWalIngesterApp : public WriteAppBase {
+ public:
+  KafkaWalIngesterApp() {}
+
+  AppType type() const override { return AppType::kBuiltIn; }
+
+  bool Query(GraphDBSession& graph, Decoder& input, Encoder& output) override;
+};
+
+class KafkaWalIngesterAppFactory : public AppFactoryBase {
+ public:
+  KafkaWalIngesterAppFactory() = default;
+  ~KafkaWalIngesterAppFactory() = default;
+
+  AppWrapper CreateApp(const GraphDB& db) override;
+};
+#endif
+
+}  // namespace gs
+
+#endif  // ENGINES_KAFKA_WAL_INGESTER_APP_H_

flex/engines/graph_db/database/graph_db.cc

@@ -28,6 +28,10 @@
 #include "flex/engines/graph_db/runtime/utils/cypher_runner_impl.h"
 #include "flex/utils/yaml_utils.h"
 
+#ifdef BUILD_KAFKA_WAL_WRITER_PARSER
+#include "flex/engines/graph_db/app/kafka_wal_ingester_app.h"
+#endif
+
 #include "flex/third_party/httplib.h"
 
 namespace gs {
@@ -52,7 +56,8 @@ struct SessionLocalContext {
   char _padding2[4096 - sizeof(GraphDBSession) % 4096];
 };
 
-GraphDB::GraphDB() = default;
+GraphDB::GraphDB()
+    : monitor_thread_running_(false), compact_thread_running_(false) {}
 GraphDB::~GraphDB() {
   if (compact_thread_running_) {
     compact_thread_running_ = false;
@@ -274,6 +279,54 @@ void GraphDB::Close() {
   std::fill(app_factories_.begin(), app_factories_.end(), nullptr);
 }
 
+#ifdef BUILD_KAFKA_WAL_WRITER_PARSER
+bool GraphDB::kafka_wal_ingester_state() const {
+  return kafka_wal_ingester_thread_running_.load();
+}
+
+void GraphDB::start_kafka_wal_ingester(const cppkafka::Configuration& config,
+                                       const std::string& topic_name) {
+  if (kafka_wal_ingester_thread_running_) {
+    kafka_wal_ingester_thread_running_ = false;
+    if (kafka_wal_ingester_thread_.joinable()) {
+      kafka_wal_ingester_thread_.join();
+    }
+  }
+  kafka_wal_ingester_thread_running_ = true;
+
+  kafka_wal_ingester_thread_ = std::thread([&]() {
+    std::vector<char> buffer;
+    gs::Encoder encoder(buffer);
+    encoder.put_string("topic_name");
+    encoder.put_string(topic_name);
+    if (config.has_property("metadata.broker.list")) {
+      encoder.put_string("metadata.broker.list");
+      encoder.put_string(config.get("metadata.broker.list"));
+    }
+    if (config.has_property("group.id")) {
+      encoder.put_string("group.id");
+      encoder.put_string(config.get("group.id"));
+    }
+    if (config.has_property("enable.auto.commit")) {
+      encoder.put_string("enable.auto.commit");
+      encoder.put_string(config.get("enable.auto.commit"));
+    }
+    if (config.has_property("auto.offset.reset")) {
+      encoder.put_string("auto.offset.reset");
+      encoder.put_string(config.get("auto.offset.reset"));
+    }
+    gs::Decoder decoder(buffer.data(), buffer.size());
+    KafkaWalIngesterApp().Query(GetSession(0), decoder, encoder);
+  });
+}
+
+void GraphDB::stop_kafka_wal_ingester() {
+  kafka_wal_ingester_thread_running_ = false;
+  kafka_wal_ingester_thread_.join();
+}
+
+#endif
+
 ReadTransaction GraphDB::GetReadTransaction(int thread_id) {
   return contexts_[thread_id].session.GetReadTransaction();
 }