uranusjr commented on code in PR #65958: URL: https://github.com/apache/airflow/pull/65958#discussion_r3298438547
########## task-sdk/src/airflow/sdk/coordinators/java/coordinator.py: ########## @@ -0,0 +1,261 @@ +# +# 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. +"""Java runtime coordinator that launches a JVM subprocess for Dag file processing and task execution.""" + +from __future__ import annotations + +import email +import os +import pathlib +import selectors +import socket +import subprocess +import time +import zipfile +from typing import TYPE_CHECKING, cast + +import attrs +import psutil +import structlog + +from airflow.sdk.execution_time.coordinator import BaseCoordinator +from airflow.sdk.execution_time.supervisor import ActivitySubprocess + +if TYPE_CHECKING: + from collections.abc import Sequence + + from structlog.typing import FilteringBoundLogger + from typing_extensions import Self + + from airflow.sdk.api.client import Client + from airflow.sdk.api.datamodels._generated import BundleInfo + from airflow.sdk.execution_time.workloads.task import TaskInstanceDTO + +log: FilteringBoundLogger = structlog.get_logger(logger_name="coordinators.java") + + +def _start_server() -> socket.socket: + server = socket.socket() + server.bind(("127.0.0.1", 0)) + server.setblocking(True) + server.listen(1) # Just need to listen to the child process. + return server + + +def _calculate_classpath(jars_root: Sequence[pathlib.Path]) -> str: + jars = (p.as_posix() for root in jars_root for p in root.iterdir() if p.suffix == ".jar") + return os.pathsep.join(jars) + + [email protected] +class _MainJar: + path: pathlib.Path + main_class: str + schema_version: str | None + + @classmethod + def find(cls, jars_root: Sequence[pathlib.Path]) -> Self: + for root in jars_root: + for p in root.iterdir(): + if p.suffix != ".jar": + continue + with zipfile.ZipFile(p) as zf: + with zf.open("META-INF/MANIFEST.MF") as f: + manifest = email.message_from_binary_file(f) + if main_class := manifest["Main-Class"]: + return cls(p, main_class, manifest.get("Airflow-SDK-Supervisor-Schema-Version")) + resolved_paths = os.pathsep.join(str(p.resolve()) for p in jars_root) + raise FileNotFoundError(f"cannot fine main class in {resolved_paths}") + + +def _accept_connections( + servers: dict[str, socket.socket], + proc: subprocess.Popen, + *, + max_wait: float = 10.0, +) -> dict[str, socket.socket]: + """Block until the Java process connects to servers.""" + accepted: dict[str, socket.socket] = {} + with selectors.DefaultSelector() as sel: + for key, soc in servers.items(): + sel.register(soc, selectors.EVENT_READ, data=key) + deadline = time.monotonic() + max_wait + while len(accepted) < len(servers): + remaining = deadline - time.monotonic() + if remaining <= 0: + raise TimeoutError("process did not connect within timeout") + if proc.poll() is not None: + raise RuntimeError(f"process exited with {proc.returncode} before connecting") + for event, _ in sel.select(timeout=min(remaining, 1.0)): + log.debug("Accepting child process connection", key=(key := event.data)) + conn, _ = cast("socket.socket", event.fileobj).accept() + sel.unregister(servers[key]) + accepted[key] = conn + return accepted + + [email protected](kw_only=True) +class _JavaActivitySubprocess(ActivitySubprocess): + """Java task runner process.""" + + _comm_server: socket.socket + _logs_server: socket.socket + _subprocess: subprocess.Popen + + # Keep track of channels used to pipe subprocess stdout and stderr so we can + # close them on exit. The "read" side is handled by _register_pipe_readers + # callbacks so we don't need to worry about them. + _stdout_w: socket.socket + _stderr_w: socket.socket + + @classmethod + def start( # type: ignore[override] + cls, + *, + what: TaskInstanceDTO, + dag_rel_path: str | os.PathLike[str], + bundle_info, + logger: FilteringBoundLogger | None = None, + sentry_integration: str = "", + java_executable: str, + jvm_args: list[str], + jars_root: Sequence[pathlib.Path], + **kwargs, + ) -> Self: + jar = _MainJar.find(jars_root) + + comm_server = _start_server() + logs_server = _start_server() + + stdout_r, stdout_w = socket.socketpair() + stderr_r, stderr_w = socket.socketpair() + + comm_host, comm_port = comm_server.getsockname() + logs_host, logs_port = logs_server.getsockname() + + proc = subprocess.Popen( + [ + java_executable, + "-classpath", + _calculate_classpath(jars_root), Review Comment: I added some descriptions on JavaCoordinator. The user is responsible for ensuring the correct Main-Class is used, either by making sure only one JAR has Main-Class, or providing one explicitly to the coordinator (see https://github.com/apache/airflow/pull/65958#pullrequestreview-4351559186). We don’t guarentee to do the right thing if this is not followed. Also added some logging to help debug issues during coordinator initialization. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
