apache/seatunnel

[Bug] [Zeta] Java process does not receive SIGTERM when running SeaTunnel inside container

Open

#9827 opened on Sep 5, 2025

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 (1 comment) (0 reactions) (1 assignee)Java (6,897 stars) (1,432 forks)batch import
bughelp wanted

Description

Search before asking

  • I had searched in the issues and found no similar issues.

What happened

When running SeaTunnel inside a Docker/Kubernetes container, the Java process cannot gracefully shut down because it never receives the SIGTERM signal sent by the container runtime. Currently, the startup script (bin/seatunnel-cluster.sh) launches Java like this (when not using -d):

java ${JAVA_OPTS} -cp ${CLASS_PATH} ${APP_MAIN} ${args}

In this case: • The shell script itself becomes PID 1 in the container. • The Java process runs as a child process of the shell. • When the container is stopped, SIGTERM is only delivered to the shell script (PID 1), not to the Java process. • The script exits immediately without forwarding the signal, leaving Java as an orphan process. • Finally, the Java process is killed by SIGKILL after the grace period, preventing SeaTunnel from shutting down gracefully.

This causes issues such as: • Shutdown hooks in Java never being executed. • Potential data loss or corruption when SeaTunnel tasks are abruptly killed.

SeaTunnel Version

2.3.11

SeaTunnel Config

none

Running Command

./bin/seatunnel-cluster -r xxx

Error Exception

none

Zeta or Flink or Spark Version

No response

Java or Scala Version

No response

Screenshots

No response

Are you willing to submit PR?

  • Yes I am willing to submit a PR!

Code of Conduct

Contributor guide

Tech stack
javashelldockerkubernetes
Domain
backenddevops
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Understanding of Docker container lifecycleShell scripting basicsJava signal handlingLinux process management
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55
Research direction
Investigate the startup script bin/seatunnel cluster.sh to modify how Java is launched so it handles SIGTERM properly. The current exec approach or signal forwarding via trap should be used. The user has expressed willingness to submit a PR. Since an assignee is set, check if any work is already in progress. Review Docker and Kubernetes best practices for PID 1 signal handling.