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0 pointshardwaresofton7y ago0 comments

Note that none of those things are impossible on kubernetes, k8s just doesn't offer them by default (which is good IMO).

There are projects that help you run databases in kubernetes and also make backups of many things hosted:

- Automatic CephFS for your cluster -> https://rook.io/docs/rook/master/

- Backups for cluster resources and volumes -> https://github.com/heptio/ark

- Spin up dynamic postgres clusters -> https://github.com/zalando-incubator/postgres-operator

Databases are just applications with different resource needs. Please stop pushing forward the notion that they can't be run in containers or container orchestration systems. Databases are just programs. If the substrate for running your containers doensn't reliably support flock or fsync or something your database needs, then maybe pick a better substrate that does -- container runtimes these days and kubernetes don't stand in your way these days.

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merb7y ago

Well with k8s 1.10+ it's also possible to use statefulsets and local volume, so with affinity it's possible to just use k8s as an orchestration system where you "install" your database and keep it up to date with k8s. of course if a node goes down you need to failover, etc. but patroni/zalando postgres works really well with statefulsets and local volume. (as long as a single node is still running, which should always be the case...) (https://kubernetes.io/blog/2018/04/13/local-persistent-volum...)

hardwaresoftonOP7y ago

I want to note that this has actually been possible since like k8s 1.7, you can just start a DB with node affinity and use hostPath volumes.

That's what I was doing until rook came around. If you're running in something like AWS (or even if you're not), you can also do something like attach an EBS volume (to a local host) and do that. Or, you can set up a plain ISCSI drive (or get one from your provider, even basic providers these days might offer storage that way) and use that.

There have been a LOT of choices for a long time.

merb7y ago

> even basic providers these days might offer storage that way

my "bare metal" provider doesn't ;)

j / k navigate · click thread line to collapse

0 pointshardwaresofton7y ago0 comments

Note that none of those things are impossible on kubernetes, k8s just doesn't offer them by default (which is good IMO).

There are projects that help you run databases in kubernetes and also make backups of many things hosted:

- Automatic CephFS for your cluster -> https://rook.io/docs/rook/master/

- Backups for cluster resources and volumes -> https://github.com/heptio/ark

- Spin up dynamic postgres clusters -> https://github.com/zalando-incubator/postgres-operator

0 comments

merb7y ago

hardwaresoftonOP7y ago

I want to note that this has actually been possible since like k8s 1.7, you can just start a DB with node affinity and use hostPath volumes.

There have been a LOT of choices for a long time.

merb7y ago

> even basic providers these days might offer storage that way

my "bare metal" provider doesn't ;)

j / k navigate · click thread line to collapse