Fail to start a distributed DB using unidirectional out-of-band peering

[rmedina97]

Fail to start a distributed DB using unidirectional out-of-band peering

[aleoli]

Hi @RiccardoStud! For better reproducibility, how do you install the MariaDB-galera cluster? Do you use an operator or chart? If yes, please indicate which

[rmedina97]

Hi @aleoli! I used the Helm chart from the Liqo guide, running the command:
helm install db bitnami/mariadb-galera -n liqo-demo -f manifests/values.yaml.
I only changed the namespace name to match mine. For additional context, when I develop the chart using only two of my clusters (one provider and one consumer), it functions normally.

[fra98]

Hi @rmedina97.
I reproduced your deployment and can confirm it is not working with this specific topology.
This is because in Liqo by design pods on different leaf clusters can't communicate directly with original IPs, but they are remapped on the external CIDR of the originating cluster. The deployment could still work in some cases:

• pods in leaf clusters connect to a pod in the originating cluster (if the DB does not require a full mesh between all replicas)
• leaf clusters are peered directly (although you do not need a bidirectional peer, just a peering in any direction). This works because leaf clusters now know each other podCIDRs and do not need to use the ExternalCIDR for IP mappings.

Please note that a new redesigned network will be merged soon and we will test again distributed DB scenarios.

[rmedina97]

Thanks for the comprehensive answer, I will adopt one of the suggested solutions for now