[Feature](Streaming Job) Extend streaming job to support MySQL synchronization

be/src/common/config.cpp

@@ -65,6 +65,8 @@ DEFINE_Int32(brpc_port, "8060");
 
 DEFINE_Int32(arrow_flight_sql_port, "8050");
 
+DEFINE_Int32(cdc_client_port, "9096");
+
 // If the external client cannot directly access priority_networks, set public_host to be accessible
 // to external client.
 // There are usually two usage scenarios:

be/src/common/config.h

@@ -100,6 +100,9 @@ DECLARE_Int32(brpc_port);
 // Default -1, do not start arrow flight sql server.
 DECLARE_Int32(arrow_flight_sql_port);
 
+// port for cdc client scan oltp cdc data
+DECLARE_Int32(cdc_client_port);
+
 // If the external client cannot directly access priority_networks, set public_host to be accessible
 // to external client.
 // There are usually two usage scenarios:

be/src/runtime/cdc_client_manager.cpp

@@ -0,0 +1,303 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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 "runtime/cdc_client_manager.h"
+
+#include <brpc/closure_guard.h>
+#include <fmt/core.h>
+#include <gen_cpp/internal_service.pb.h>
+#include <google/protobuf/stubs/callback.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#ifndef __APPLE__
+#include <sys/prctl.h>
+#endif
+
+#include <atomic>
+#include <chrono>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#include "common/config.h"
+#include "common/logging.h"
+#include "common/status.h"
+#include "http/http_client.h"
+
+namespace doris {
+
+namespace {
+// Handle SIGCHLD signal to prevent zombie processes
+void handle_sigchld(int sig_no) {
+    int status = 0;
+    pid_t pid = waitpid(0, &status, WNOHANG);
+    LOG(INFO) << "handle cdc process exit, result: " << pid << ", status: " << status;
+}
+
+// Check CDC client health
+Status check_cdc_client_health(int retry_times, int sleep_time, std::string& health_response) {
+    const std::string cdc_health_url =
+            "http://127.0.0.1:" + std::to_string(doris::config::cdc_client_port) +
+            "/actuator/health";
+
+    auto health_request = [cdc_health_url, &health_response](HttpClient* client) {
+        RETURN_IF_ERROR(client->init(cdc_health_url));
+        client->set_timeout_ms(5000);
+        RETURN_IF_ERROR(client->execute(&health_response));
+        return Status::OK();
+    };
+
+    Status status = HttpClient::execute_with_retry(retry_times, sleep_time, health_request);
+
+    if (!status.ok()) {
+        return Status::InternalError(
+                fmt::format("CDC client health check failed: url={}", cdc_health_url));
+    }
+
+    bool is_up = health_response.find("UP") != std::string::npos;
+
+    if (!is_up) {
+        return Status::InternalError(fmt::format("CDC client unhealthy: url={}, response={}",
+                                                 cdc_health_url, health_response));
+    }
+
+    return Status::OK();
+}
+
+} // anonymous namespace
+
+CdcClientMgr::CdcClientMgr() = default;
+
+CdcClientMgr::~CdcClientMgr() {
+    stop();
+    LOG(INFO) << "CdcClientMgr is destroyed";
+}
+
+void CdcClientMgr::stop() {
+    pid_t pid = _child_pid.load();
+    if (pid > 0) {
+        // Check if process is still alive
+        if (kill(pid, 0) == 0) {
+            LOG(INFO) << "Stopping CDC client process, pid=" << pid;
+
+            // Send SIGTERM for graceful shutdown
+            if (kill(pid, SIGTERM) == 0) {
+                // Wait up to 10 seconds for graceful shutdown
+                for (int i = 0; i < 10; ++i) {
+                    std::this_thread::sleep_for(std::chrono::seconds(1));
+                    if (kill(pid, 0) != 0) {
+                        // Process has exited
+                        _child_pid.store(0);
+                        LOG(INFO) << "CDC client process stopped gracefully";
+                        return;
+                    }
+                }
+            }
+
+            // Force kill if still alive
+            if (kill(pid, 0) == 0) {
+                LOG(WARNING) << "Force killing CDC client process, pid=" << pid;
+                kill(pid, SIGKILL);
+                // Wait for process to exit
+                int status = 0;
+                waitpid(pid, &status, 0);
+            }
+            _child_pid.store(0);
+        } else {
+            // Process already dead
+            _child_pid.store(0);
+        }
+    }
+
+    LOG(INFO) << "CdcClientMgr is stopped";
+}
+
+Status CdcClientMgr::start_cdc_client(PRequestCdcClientResult* result) {
+    std::lock_guard<std::mutex> lock(_start_mutex);
+
+    pid_t existing_pid = _child_pid.load();
+    if (existing_pid > 0) {
+        // Check if process is still alive
+        if (kill(existing_pid, 0) == 0) {
+            std::string check_response;
+            auto check_st = check_cdc_client_health(1, 0, check_response);
+            if (check_st.ok()) {
+                LOG(INFO) << "cdc client already started, pid=" << existing_pid;
+                return Status::OK();
+            } else {
+                // Process exists but not healthy, reset PID
+                LOG(WARNING) << "CDC client process exists but unhealthy, pid=" << existing_pid;
+                _child_pid.store(0);
+            }
+        } else {
+            // Process is dead, reset PID
+            _child_pid.store(0);
+        }
+    }
+
+    Status st = Status::OK();
+
+    const char* doris_home = getenv("DORIS_HOME");
+    if (!doris_home) {
+        st = Status::InternalError("DORIS_HOME environment variable is not set");
+        if (result) {
+            st.to_protobuf(result->mutable_status());
+        }
+        return st;
+    }
+
+    const char* log_dir = getenv("LOG_DIR");
+    if (!log_dir) {
+        st = Status::InternalError("LOG_DIR environment variable is not set");
+        if (result) {
+            st.to_protobuf(result->mutable_status());
+        }
+        return st;
+    }
+
+    const std::string cdc_jar_path = std::string(doris_home) + "/lib/cdc_client/cdc-client.jar";
+    const std::string cdc_jar_port =
+            "--server.port=" + std::to_string(doris::config::cdc_client_port);
+    const std::string backend_http_port =
+            "--backend.http.port=" + std::to_string(config::webserver_port);
+    const std::string java_opts = "-Dlog.path=" + std::string(log_dir);
+
+    // check cdc jar exists
+    struct stat buffer;
+    if (stat(cdc_jar_path.c_str(), &buffer) != 0) {
+        st = Status::InternalError("Can not find cdc-client.jar.");
+        if (result) {
+            st.to_protobuf(result->mutable_status());
+        }
+        return st;
+    }
+
+    // check cdc process already started
+    std::string check_response;
+    auto check_st = check_cdc_client_health(1, 0, check_response);
+    if (check_st.ok()) {
+        LOG(INFO) << "cdc client already started.";
+        return Status::OK();
+    } else {
+        LOG(INFO) << "cdc client not started, to start.";
+    }
+
+    const auto* java_home = getenv("JAVA_HOME");
+    if (!java_home) {
+        st = Status::InternalError("Can not find java home.");
+        if (result) {
+            st.to_protobuf(result->mutable_status());
+        }
+        return st;
+    }
+    std::string path(java_home);
+
+    // Capture signal to prevent child process from becoming a zombie process
+    struct sigaction act;
+    act.sa_flags = 0;
+    act.sa_handler = handle_sigchld;
+    sigaction(SIGCHLD, &act, NULL);
+    LOG(INFO) << "Start to fork cdc client process with " << path;
+
+    pid_t pid = ::fork();
+    if (pid < 0) {
+        // Fork failed
+        st = Status::InternalError("Fork cdc client failed.");
+        if (result) {
+            st.to_protobuf(result->mutable_status());
+        }
+        return st;
+    } else if (pid == 0) {
+        // Child process
+        // When the parent process is killed, the child process also needs to exit
+#ifndef __APPLE__
+        prctl(PR_SET_PDEATHSIG, SIGKILL);
+#endif
+
+        LOG(INFO) << "Cdc client child process ready to start";
+        std::cout << "Cdc client child process ready to start." << std::endl;
+        std::string java_bin = path + "/bin/java";
+        // java -jar -Dlog.path=xx cdc-client.jar --server.port=9096 --backend.http.port=8040
+        execlp(java_bin.c_str(), "java", java_opts.c_str(), "-jar", cdc_jar_path.c_str(),
+               cdc_jar_port.c_str(), backend_http_port.c_str(), (char*)NULL);
+        std::cerr << "Cdc client child process error." << std::endl;
+        exit(1);
+    } else {
+        // Parent process: save PID and wait for startup
+        _child_pid.store(pid);
+
+        // Waiting for cdc to start, failed after more than 30 seconds
+        std::string health_response;
+        Status status = check_cdc_client_health(5, 6, health_response);
+        if (!status.ok()) {
+            // Reset PID if startup failed
+            _child_pid.store(0);
+            st = Status::InternalError("Start cdc client failed.");
+            if (result) {
+                st.to_protobuf(result->mutable_status());
+            }
+        } else {
+            LOG(INFO) << "Start cdc client success, pid=" << pid
+                      << ", status=" << status.to_string() << ", response=" << health_response;
+        }
+    }
+    return st;
+}
+
+void CdcClientMgr::request_cdc_client_impl(const PRequestCdcClientRequest* request,
+                                           PRequestCdcClientResult* result,
+                                           google::protobuf::Closure* done) {
+    VLOG_RPC << "request to cdc client, api " << request->api();
+    brpc::ClosureGuard closure_guard(done);
+
+    // Start CDC client if not started
+    Status start_st = start_cdc_client(result);
+    if (!start_st.ok()) {
+        LOG(ERROR) << "Failed to start CDC client, status=" << start_st.to_string();
+        start_st.to_protobuf(result->mutable_status());
+        return;
+    }
+
+    std::string cdc_response;
+    Status st = send_request_to_cdc_client(request->api(), request->params(), &cdc_response);
+    result->set_response(cdc_response);
+    st.to_protobuf(result->mutable_status());
+}
+
+Status CdcClientMgr::send_request_to_cdc_client(const std::string& api,
+                                                const std::string& params_body,
+                                                std::string* response) {
+    std::string remote_url_prefix =
+            fmt::format("http://127.0.0.1:{}{}", doris::config::cdc_client_port, api);
+
+    auto cdc_request = [&remote_url_prefix, response, &params_body](HttpClient* client) {
+        RETURN_IF_ERROR(client->init(remote_url_prefix));
+        client->set_timeout_ms(60 * 1000);
+        if (!params_body.empty()) {
+            client->set_payload(params_body);
+        }
+        client->set_content_type("application/json");
+        client->set_method(POST);
+        RETURN_IF_ERROR(client->execute(response));
+        return Status::OK();
+    };
+
+    return HttpClient::execute_with_retry(3, 1, cdc_request);
+}
+
+} // namespace doris

be/src/runtime/cdc_client_manager.h

@@ -0,0 +1,56 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#pragma once
+
+#include <gen_cpp/internal_service.pb.h>
+
+#include <atomic>
+#include <mutex>
+#include <string>
+
+#include "common/status.h"
+
+namespace google::protobuf {
+class Closure;
+class RpcController;
+} // namespace google::protobuf
+
+namespace doris {
+
+class CdcClientMgr {
+public:
+    CdcClientMgr();
+    ~CdcClientMgr();
+
+    void stop();
+
+    // Request CDC client to handle a request
+    void request_cdc_client_impl(const PRequestCdcClientRequest* request,
+                                 PRequestCdcClientResult* result, google::protobuf::Closure* done);
+
+private:
+    Status send_request_to_cdc_client(const std::string& api, const std::string& params_body,
+                                      std::string* response);
+
+    Status start_cdc_client(PRequestCdcClientResult* result);
+
+    std::mutex _start_mutex;
+    std::atomic<pid_t> _child_pid {0};
+};
+
+} // namespace doris