When starting Stardog Cluster on existing volumes it's possible to encounter the following error:
Cannot start kernel since there are no other nodes in the cluster to sync up
This happens because the latest tx id is stored in ZK and the Stardog cluster node with a matching tx id needs to start first. With k8s this can be problematic because the default nature of statefulsets starts them in an ordered fashion so if the first node doesn't match the tx id then the deployment hangs and no other pods are deployed.
The setting podMangementPolicy: Parallel can be set on the Stardog statefulset to start all of the Stardog pods at the same time, which allows the pod with the matching tx id to start and the other nodes to sync.
pdmars
commented
3 years ago
When starting Stardog Cluster on existing volumes it's possible to encounter the following error:
This happens because the latest tx id is stored in ZK and the Stardog cluster node with a matching tx id needs to start first. With k8s this can be problematic because the default nature of statefulsets starts them in an ordered fashion so if the first node doesn't match the tx id then the deployment hangs and no other pods are deployed.
The setting
podMangementPolicy: Parallelcan be set on the Stardog statefulset to start all of the Stardog pods at the same time, which allows the pod with the matching tx id to start and the other nodes to sync.We should make this a configurable option.