3 ms·

good thing kubernetes can restart pods fast and have persistent volumes!

falcolas 6y ago
Persistant volumes rely on NFS (or a flavor thereof), which is not great for database performance. But that's a moot point anyways, since Vitess doesn't use persistent volumes - it reloads the individual DBs from backups and binlogs when a pod is moved or restarted.
- roman_sf 6y ago
  couldn't they shovel it into dynamodb?
  - falcolas 6y ago
    Theoretically, sure. But Vitess is - as Kubernetes is - provider agnostic. But if you’re talking about the DB, sure to that too. But, not my decision.
    - roman_sf 6y ago
      Yeah, I've seen these resume-driven, anti-vendor-locking, everything-is-a-nail-for-kubernetes-hummer decisions :)
- snuxoll 6y ago
  > Persistant volumes rely on NFS (or a flavor thereof), which is not great for database performance. NFS is an option, but it’s not the only option. If you need locally attached storage you can use local PV’s which went GA in Kubernetes 1.14, or any of the plethora of volume plugins that exist for various network storage solutions.
  - falcolas 6y ago
    Network storage, NFS or other, is never optimal for DB storage. It can and is used, but it’s never going to be as good as local storage. I had forgotten about local storage; it’s not something we can use in our environment. It’s a moot point, in either case. Vitess doesn’t rely on persistent storage, it relies on replicas and backups.
- dilyevsky 6y ago
  Are you saying that iscsi is a “flavor of nfs”? What makes it not suitable for good db performance?
  - falcolas 6y ago
    I sincerely beg your forgiveness for forgetting about a feature that’s only about a year old, and a feature we can’t take advantage of in our own kubernetes environment, or with the Vitess cluster. Forest, trees.
    - dilyevsky 6y ago
      You should leave snark for topics you have some knowledge of. PVs based on network attached drives have been around from the very start. Their performance is quite good. Vitess can use them (https://github.com/vitessio/vitess/tree/master/helm/vitess#custom-pvc-for-mysql-data https://github.com/vitessio/vitess/tree/master/helm/vitess#c...)

Persistant volumes rely on NFS (or a flavor thereof), which is not great for database performance. But that's a moot point anyways, since Vitess doesn't use persistent volumes - it reloads the individual DBs from backups and binlogs when a pod is moved or restarted.

roman_sf 6y ago
couldn't they shovel it into dynamodb?
- falcolas 6y ago
  Theoretically, sure. But Vitess is - as Kubernetes is - provider agnostic. But if you’re talking about the DB, sure to that too. But, not my decision.
  - roman_sf 6y ago
    Yeah, I've seen these resume-driven, anti-vendor-locking, everything-is-a-nail-for-kubernetes-hummer decisions :)
snuxoll 6y ago
> Persistant volumes rely on NFS (or a flavor thereof), which is not great for database performance. NFS is an option, but it’s not the only option. If you need locally attached storage you can use local PV’s which went GA in Kubernetes 1.14, or any of the plethora of volume plugins that exist for various network storage solutions.
- falcolas 6y ago
  Network storage, NFS or other, is never optimal for DB storage. It can and is used, but it’s never going to be as good as local storage. I had forgotten about local storage; it’s not something we can use in our environment. It’s a moot point, in either case. Vitess doesn’t rely on persistent storage, it relies on replicas and backups.
dilyevsky 6y ago
Are you saying that iscsi is a “flavor of nfs”? What makes it not suitable for good db performance?
- falcolas 6y ago
  I sincerely beg your forgiveness for forgetting about a feature that’s only about a year old, and a feature we can’t take advantage of in our own kubernetes environment, or with the Vitess cluster. Forest, trees.
  - dilyevsky 6y ago
    You should leave snark for topics you have some knowledge of. PVs based on network attached drives have been around from the very start. Their performance is quite good. Vitess can use them (https://github.com/vitessio/vitess/tree/master/helm/vitess#custom-pvc-for-mysql-data https://github.com/vitessio/vitess/tree/master/helm/vitess#c...)