Intermittent 409 Conflict on self hosted Mac OS runner

Question

Hi,

I'm getting intermittent 409 Conflict errors ("Simultaneous state updates") on my self-hosted runners.

My Setup:

* Single Mac machine running multiple runner processes.

* Custom run.sh script: I launch the runner by passing all configurations (UUID, OAuth, WorkingDir) directly via command-line arguments.

Verification:

* Unique Configs: I manually verified that every script passes a unique UUID, Client ID, and working directory.

* Process Check: ps -ef confirms no duplicate processes are running for the same UUID.

Since I am strictly using unique CLI arguments for each process, I don't understand why the server detects a conflict. Has anyone faced this issue?

[Error Log]

[2026-01-26 16:52:36,488] ...
com.atlassian.pipelines.stargate.client.core.exceptions.StargateConflictException: ...
"message":"Simultaneous state updates were attempted for runner with id: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}"

Thanks.

Shane_Yoo · Answer

@Taliah15

I killed all processes using the command you provided and added a 5-second delay between starting each runner, but the issue still persists.The directory structure is as follows:```// ~/Desktop└── runners    ├── login-item.command    ├── mobile-workspace-01    │   ├── atlassian-bitbucket-pipelines-runner    │   ├── atlassian-bitbucket-pipelines-runner.tar.gz    │   ├── log.log    │   └── run.sh    ├── mobile-workspace-02        ├── atlassian-bitbucket-pipelines-runner        ├── atlassian-bitbucket-pipelines-runner.tar.gz        ├── log.log        └── run.sh```The run.sh script that starts each runner is as follows:```# run.sh#!/usr/bin/env bashcd atlassian-bitbucket-pipelines-runner/binnohup ./start.sh --accountUuid {REDACTED_ACNT_ID} --repositoryUuid {REDACTED_REPO_ID} --runnerUuid {REDACTED_RNNR_ID} --OAuthClientId {REDACTED_CLIENT_ID} --OAuthClientSecret {REDACTED_CLIENT_SECRET} --runtime macos-bash --workingDirectory ../temp > ../../log.log 2>&1 &```This run.sh exists in each runner directory and is executed by the following script:```# login-item.command#!/bin/bash# This script will be executed when build machine booted.# run mobile workspace runnersleep 5cd ~/Desktop/runners/mobile-workspace-01./run.shsleep 5cd ~/Desktop/runners/mobile-workspace-02./run.sh# close terminalosascript -e 'tell application "Terminal" to close first window' & exit```The errors logged in log.log include 401, 403, 409, and Connection reset, occurring intermittently.```# 403[2026-01-27 16:43:23,147] An error occurred whilst completing step.com.atlassian.pipelines.stargate.client.core.exceptions.StargateForbiddenException: Response Summary: HttpResponseSummary{httpStatusCode=403, httpStatusMessage=Forbidden, bodyAsString={"error":{"message":"Forbidden","detail":"Runner currently has no pipeline scheduled.","data":{"key":"rest-service.rest-service.forbidden","arguments":{}}}}}at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(Unknown Source)Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:Error has been observed at the following site(s):*__checkpoint ⇢ 403 from POST https://api.atlassian.com/ex/bitbucket-pipelines/rest/1.0/accounts/.../stepComplete [DefaultWebClient]Original Stack Trace:``````# 401[2026-01-27 16:42:41,902] An error occurred whilst updating runner state to "ONLINE".com.atlassian.pipelines.stargate.client.core.exceptions.StargateUnauthorizedException: Response Summary: HttpResponseSummary{httpStatusCode=401, httpStatusMessage=Unauthorized, bodyAsString={"code":401,"message":"Unauthorized"}}at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(Unknown Source)Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:Error has been observed at the following site(s):*__checkpoint ⇢ 401 from PUT https://api.atlassian.com/ex/bitbucket-pipelines/rest/internal/accounts/.../state [DefaultWebClient]Original Stack Trace:``````# 409[2026-01-27 16:32:42,500] Uncaught error from RxJavacom.atlassian.pipelines.stargate.client.core.exceptions.StargateConflictException: Response Summary: HttpResponseSummary{httpStatusCode=409, httpStatusMessage=Conflict, bodyAsString={"key":"agent-service.runner.conflict","message":"Simultaneous state updates were attempted for runner with id: {...}","arguments":{}}}at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(Unknown Source)Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:Error has been observed at the following site(s):*__checkpoint ⇢ 409 from PUT https://api.atlassian.com/ex/bitbucket-pipelines/rest/internal/accounts/.../state [DefaultWebClient]Original Stack Trace:``````# connection reset[2026-01-28 07:35:12,008] [REDACTED_ID, L:/REDACTED_IP:56827 - R:api.atlassian.com/13.227.180.4:443] The connection observed an errorjava.net.SocketException: Connection resetat java.base/sun.nio.ch.SocketChannelImpl.throwConnectionReset(Unknown Source)at java.base/sun.nio.ch.SocketChannelImpl.read(Unknown Source)at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:255)at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1132)at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:356)at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:151)at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:796)at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:732)at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:658)at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998)at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)at java.base/java.lang.Thread.run(Unknown Source)```

Taliah15 · Answer

@Shane_Yoo  I will wait for your response.

Shane_Yoo · Answer

I'll try your solution and let you know if this works or not.

Thank you for quick response!