RabbitMQ Failing to Startup on 7.9.0 with "required feature flag not enabled!"

Products

• Carbon Black EDR

Issue/Introduction

When upgrading to 7.9.0, RabbitMQ fails to startup or times out. In /var/log/cb/rabbitmq/startup_log a message similar to this is found. 

Starting rabbitmq
2025-11-20 09:52:06.303110-06:00 [error] <0.234.0> Feature flags: `stream_single_active_consumer`: required feature flag not enabled! It must be enabled before upgrading RabbitMQ.
2025-11-20 09:52:06.309796-06:00 [error] <0.234.0> Failed to initialize feature flags registry: {disabled_required_feature_flag,
2025-11-20 09:52:06.309796-06:00 [error] <0.234.0>                                               stream_single_active_consumer}
2025-11-20 09:52:06.316446-06:00 [error] <0.234.0>
2025-11-20 09:52:06.316446-06:00 [error] <0.234.0> BOOT FAILED
2025-11-20 09:52:06.316446-06:00 [error] <0.234.0> ===========
2025-11-20 09:52:06.316446-06:00 [error] <0.234.0> Error during startup: {error,failed_to_initialize_feature_flags_registry}

Environment

• Carbon Black EDR Server: 7.9.0 and Higher

Cause

• Required upgrade path in Server version 7.9.0 release notes were not followed.
• Older EDR servers may not have the feature flags enabled that are required for rabbitmq-server 3.11 and higher. 

Resolution

1. Ensure valid access token for Carbon Black Yum repository.

Authenticate to Packages Repository

2. Uninstall the 3.11 rabbitmq-server without dependencies 

rpm -e --nodeps rabbitmq-server

3. Update the CarbonBlack.repo baseurl to point to 7.8.0-1 repository

vi /etc/yum.repos.d/CarbonBlack.repo

Change the last portion of the baseurl from 7.9.0-1 to 7.8.0-1

...packages.broadcom.com/artifactory/carbonblack-edr/7.9.0-1/$releasever/$basearch

to

...packages.broadcom.com/artifactory/carbonblack-edr/7.8.0-1/$releasever/$basearch

4. Clean yum cache 

yum clean all

5. Download the rabbitmq-server-3.10.20-1 rpm package. 

yum install --downloadonly --downloaddir=/tmp rabbitmq-server* -y --disablerepo=* --enablerepo=CarbonBlack

6. Install the 3.10.20 rabbitmq-server 

rpm -i /tmp/rabbitmq-server-3.10.20-1.el8.noarch.rpm

7. Startup rabbitmq alone through the cbservice script 

/usr/share/cb/cbservice cb-rabbitmq start

8. Enable the feature flags 

/usr/share/cb/cbrabbitmqctl enable_feature_flag all

9. Stop rabbitmq alone through the cbservice script 

/usr/share/cb/cbservice cb-rabbitmq stop

10. Uninstall the 3.10.20 rabbitmq-server without dependencies 

rpm -e --nodeps rabbitmq-server

11. Update the CarbonBlack.repo to point back to the 7.8.1 release. 

vi /etc/yum.repos.d/CarbonBlack.repo

Change the last portion of the baseurl from 7.8.0-1 to 7.8.1

...packages.broadcom.com/artifactory/carbonblack-edr/7.8.0-1/$releasever/$basearch

to

...packages.broadcom.com/artifactory/carbonblack-edr/7.8.1/$releasever/$basearch

12. Clean the yum cache 

yum clean all

13. Remove the 3.10.20 download from /tmp. 

rm -f /tmp/rabbitmq-server-3.10.20-1.el8.noarch.rpm

14. Download the 3.11.24 rabbitmq-server. Note: this will force dependency packages to be downgraded. 

yum install rabbitmq-server* -y --disablerepo=* --enablerepo=CarbonBlack

15. Startup rabbitmq alone through the cbservice script 

/usr/share/cb/cbservice cb-rabbitmq start

16. Validate/Enable the feature flags 

/usr/share/cb/cbrabbitmqctl enable_feature_flag all

17. Stop rabbitmq alone through the cbservice script 

/usr/share/cb/cbservice cb-rabbitmq stop

18. Update the CarbonBlack.repo to point back to the 7.9.0-1 release. 

vi /etc/yum.repos.d/CarbonBlack.repo

Change the last portion of the baseurl from 7.8.1 to 7.9.0-1

...packages.broadcom.com/artifactory/carbonblack-edr/7.8.1/$releasever/$basearch

to

...packages.broadcom.com/artifactory/carbonblack-edr/7.9.0-1/$releasever/$basearch

19. Clean the yum cache 

yum clean all

20. Upgrade the 3.12.13 rabbitmq-server and dependencies

yum upgrade cb-enterprise

21. If selinux is enabled, the permissions labels may need to be updated. 

/usr/share/cb/cbcheck selinux -a

22. Attempt to start services.

/usr/share/cb/cbservices cb-enterprise start

Additional Information

• https://techdocs.broadcom.com/us/en/carbon-black/edr/carbon-black-edr/7-9-0/release-notes/edr-7-9.html
• https://www.rabbitmq.com/blog/2022/07/20/required-feature-flags-in-rabbitmq-3.11
• https://techdocs.broadcom.com/us/en/carbon-black/edr/carbon-black-edr/7-9-0/scm-guide-edr/GUID-5C321527-7A2D-4C62-95AE-0E27AD9190FD-en/authenticate-to-packages-repository.html