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AWS peer discovery: add multi-hostname path support#14705

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michaelklishin merged 2 commits intorabbitmq:mainfrom
BenAtAmazon:aws/add-peer-discovery-multi-hostname-path
Feb 4, 2026
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AWS peer discovery: add multi-hostname path support#14705
michaelklishin merged 2 commits intorabbitmq:mainfrom
BenAtAmazon:aws/add-peer-discovery-multi-hostname-path

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@BenAtAmazon BenAtAmazon commented Oct 7, 2025 •
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Proposed Changes

This PR adds support for multiple hostname paths in the AWS peer discovery plugin to enable zero-downtime rolling upgrades during hostname migration scenarios. The implementation allows RabbitMQ nodes to discover peers using multiple hostname paths, ensuring cluster formation succeeds even when nodes are configured with different hostname paths during rolling upgrades.

Backward Compatibility

Existing single hostname_path configuration continues to work (unchanged).
We fallback to single path behavior when no numbered paths are configured.

Configuration Examples

Multiple paths for zero-downtime migration
cluster_formation.aws.hostname_path.1 = networkInterfaceSet,2,privateIpAddressesSet,1,privateDnsName
cluster_formation.aws.hostname_path.2 = privateDnsName
cluster_formation.aws.hostname_path.3 = networkInterfaceSet,1,privateIpAddressesSet,2,privateIpAddress

Note: This follows the existing pattern we have for classic_config:

cluster_formation.classic_config.nodes.1 = rabbit@<hostnameA>
cluster_formation.classic_config.nodes.2 = rabbit@<hostnameB>
cluster_formation.classic_config.nodes.3 = rabbit@<hostnameC>
Single path (backward compatible)
cluster_formation.aws.hostname_path = privateDnsName

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  • Bug fix (non-breaking change which fixes issue #NNNN)
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SimonUnge
SimonUnge reviewed Oct 8, 2025
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SimonUnge
SimonUnge reviewed Oct 8, 2025
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SimonUnge
SimonUnge reviewed Oct 8, 2025
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lukebakken
lukebakken requested changes Oct 8, 2025
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Please be aware that the genie is extremely lazy with whitespace and will gladly add space characters on blank lines, at the end of lines, etc.

@BenAtAmazon BenAtAmazon force-pushed the aws/add-peer-discovery-multi-hostname-path branch from ca6b404 to 175a956 Compare October 10, 2025 03:06
SimonUnge
SimonUnge suggested changes Oct 10, 2025
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lukebakken
lukebakken reviewed Oct 10, 2025
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@BenAtAmazon BenAtAmazon force-pushed the aws/add-peer-discovery-multi-hostname-path branch 2 times, most recently from b75758a to 7cdb505 Compare October 15, 2025 19:53
BenAtAmazon
BenAtAmazon commented Oct 15, 2025
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@lukebakken lukebakken force-pushed the aws/add-peer-discovery-multi-hostname-path branch 2 times, most recently from b67ffb1 to c0c79bf Compare October 22, 2025 15:18
lukebakken
lukebakken approved these changes Oct 22, 2025
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👍 thanks!

@lukebakken lukebakken self-assigned this Oct 22, 2025
the-mikedavis
the-mikedavis approved these changes Oct 22, 2025
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This looks good to me, I just have a minor suggestion about being more assertive in the schema for this config

BenAtAmazon and others added 2 commits February 3, 2026 22:59
@BenAtAmazon @lukebakken
AWS peer discovery: add multi-hostname path support
8809b6e 
Adds support for multiple hostname paths in the AWS peer discovery plugin to enable zero-downtime rolling upgrades during hostname migration scenarios.

The implementation allows RabbitMQ nodes to discover peers using multiple hostname paths, ensuring cluster formation succeeds even when nodes are configured with different hostname paths during rolling upgrades.

Example usage:

cluster_formation.aws.hostname_path.1 = privateDnsName
cluster_formation.aws.hostname_path.2 = privateIpAddress

Move tests that need per-test init and end to dedicated file.
@lukebakken @the-mikedavis
Update deps/rabbitmq_peer_discovery_aws/priv/schema/rabbitmq_peer_dis…
51981e2 
…covery_aws.schema

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>
@lukebakken lukebakken force-pushed the aws/add-peer-discovery-multi-hostname-path branch from 2a3274a to 51981e2 Compare February 3, 2026 23:00
@michaelklishin michaelklishin added this to the 4.3.0 milestone Feb 4, 2026
@michaelklishin michaelklishin merged commit 3cf800e into rabbitmq:main Feb 4, 2026
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@mergify mergify bot mentioned this pull request Feb 4, 2026
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michaelklishin added a commit that referenced this pull request Feb 4, 2026
@michaelklishin
Merge pull request #15395 from rabbitmq/mergify/bp/v4.2.x/pr-14705
83c258f 
AWS peer discovery: add multi-hostname path support (backport #14705)
lukebakken pushed a commit to lukebakken/rmq-rabbitmq-server that referenced this pull request Mar 17, 2026
@michaelklishin @lukebakken
Merge pull request rabbitmq#14705 from BenAtAmazon/aws/add-peer-disco…
3401ef7 
…very-multi-hostname-path

AWS peer discovery: add multi-hostname path support

(cherry picked from commit 3cf800e)
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@lukebakken lukebakken lukebakken approved these changes

@the-mikedavis the-mikedavis the-mikedavis approved these changes

@SimonUnge SimonUnge Awaiting requested review from SimonUnge

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