feat(ZFSPV): volume count based scheduler for ZFSPV (#8)

This is an initial scheduler implementation for ZFS Local PV. 

* adding scheduler as a configurable option
* adding volumeWeightedScheduler as scheduling logic

The volumeWeightedScheduler  will go through all the nodes as per
topology information and it will pick the node which has less
volume provisioned in the given pool.

lets say there are 2 nodes node1 and node2 with below pool configuration :-
```
node1
|
|-----> pool1
|         |
|         |------> pvc1
|         |------> pvc2
|-----> pool2
          |------> pvc3

node2
|
|-----> pool1
|         |
|         |------> pvc4
|-----> pool2
          |------> pvc5
          |------> pvc6
```
So if application is using pool1 as shown in the below storage class, then ZFS driver will schedule it on node2 as it has one volume as compared to node1 which has 2 volumes in pool1.
```yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: openebs-zfspv
provisioner: zfs.csi.openebs.io
parameters:
  blocksize: "4k"
  compression: "on"
  dedup: "on"
  thinprovision: "yes"
  poolname: "pool1"
```

So if application is using pool2 as shown in the below storage class, then ZFS driver will schedule it on node1 as it has one volume only as compared node2 which has 2 volumes in pool2.
```yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: openebs-zfspv
provisioner: zfs.csi.openebs.io
parameters:
  blocksize: "4k"
  compression: "on"
  dedup: "on"
  thinprovision: "yes"
  poolname: "pool2"
```
In case of same number of volumes on all the nodes for the given pool, it can pick any node and schedule the PV on that.

Signed-off-by: Pawan <pawan@mayadata.io>
This commit is contained in:
Pawan Prakash Sharma 2019-11-06 21:20:49 +05:30 committed by Kiran Mova
parent d0e97cddb2
commit a10dedbd5e
7 changed files with 114 additions and 18 deletions

View file

@ -118,7 +118,6 @@ func UpdateZvolInfo(vol *apis.ZFSVolume) error {
}
newVol, err := builder.BuildFrom(vol).
WithNodename(NodeID).
WithFinalizer(finalizers).
WithLabels(labels).Build()