Intermittent 409 Conflict on self hosted Mac OS runner

[Shane_Yoo]

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.

[Taliah15]

Hello, runner-wrangler!

That 409 "Simultaneous state updates" on the multi-runner configuration on your Mac? Classic gotcha: processes can collide while racing to heartbeat to Bitbucket's Stargate service, even with distinct UUIDs and CLI arguments.

Fast fixes:

pkill -f runner, then restart each one individually, looking for dupes in the tail logs.

To serialize starts, use staggered delays or the --once flag in run.sh.

Use lsof | grep runner or shared locks (such as /tmp state) to look for zombie processes.

Worked for others on a Mac; if the runner version is out of date, update that as well. Are you still stuck? Share the entire run.sh snippet!

Go for those insects! @Shane_Yoo  If this works kindly let me know. 

[Shane_Yoo]

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

Thank you for quick response!

[Taliah15]

@Shane_Yoo  I will wait for your response. 

[Shane_Yoo]

@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 bash

cd atlassian-bitbucket-pipelines-runner/bin

nohup ./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 runner

sleep 5

cd ~/Desktop/runners/mobile-workspace-01

./run.sh

sleep 5

cd ~/Desktop/runners/mobile-workspace-02

./run.sh

# close terminal

osascript -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 RxJava

com.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 error

java.net.SocketException: Connection reset

at 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)

```