mirror of
https://github.com/featurebasedb/featurebase.git
synced 2026-08-28 10:54:59 +00:00
dee46d4423
We default to the jmp-hash method which we had previously, and allow a user to set the "modulus" option which uses a simple mod operation to ensure an even spread of partitions across nodes. I think that ideally we would have new indexes uses modulus and existing indexes use jmp-hash which implies supporting this configuration on a per-index basis. If we don't do per index, we should probably run the whole test suite both ways.
96 lines
2.3 KiB
Go
96 lines
2.3 KiB
Go
// Copyright 2021 Molecula Corp. All rights reserved.
|
|
package topology
|
|
|
|
import (
|
|
"sort"
|
|
)
|
|
|
|
// Noder is an interface which abstracts the Node slice so that the list of
|
|
// nodes in a cluster can be maintained outside of the cluster struct.
|
|
type Noder interface {
|
|
Nodes() []*Node // Remember: this has to be sorted correctly!!
|
|
PrimaryNodeID(hasher Hasher) string
|
|
SetNodes([]*Node)
|
|
AppendNode(*Node)
|
|
RemoveNode(nodeID string) bool
|
|
}
|
|
|
|
// localNoder is a simple implementation of the Noder interface
|
|
// which maintains an instance of the `nodes` slice.
|
|
type localNoder struct {
|
|
nodes []*Node
|
|
}
|
|
|
|
// NewLocalNoder is a helper function for wrapping an existing slice of Nodes
|
|
// with something which implements Noder.
|
|
func NewLocalNoder(nodes []*Node) *localNoder {
|
|
return &localNoder{
|
|
nodes: nodes,
|
|
}
|
|
}
|
|
|
|
// NewEmptyLocalNoder is an empty Noder used for testing.
|
|
func NewEmptyLocalNoder() *localNoder {
|
|
return &localNoder{}
|
|
}
|
|
|
|
// NewIDNoder is a helper function for wrapping an existing slice of Node IDs
|
|
// with something which implements Noder.
|
|
func NewIDNoder(ids []string) *localNoder {
|
|
nodes := make([]*Node, len(ids))
|
|
for i, id := range ids {
|
|
node := &Node{
|
|
ID: id,
|
|
}
|
|
nodes[i] = node
|
|
}
|
|
|
|
// Nodes must be sorted.
|
|
sort.Sort(ByID(nodes))
|
|
|
|
return &localNoder{
|
|
nodes: nodes,
|
|
}
|
|
}
|
|
|
|
// Nodes implements the Noder interface.
|
|
func (n *localNoder) Nodes() []*Node {
|
|
return n.nodes
|
|
}
|
|
|
|
// PrimaryNodeID implements the Noder interface.
|
|
func (n *localNoder) PrimaryNodeID(hasher Hasher) string {
|
|
snap := NewClusterSnapshot(NewLocalNoder(n.nodes), hasher, "jmp-hash", 1)
|
|
primaryNode := snap.PrimaryFieldTranslationNode()
|
|
if primaryNode == nil {
|
|
return ""
|
|
}
|
|
return primaryNode.ID
|
|
}
|
|
|
|
// SetNodes implements the Noder interface.
|
|
func (n *localNoder) SetNodes(nodes []*Node) {
|
|
n.nodes = nodes
|
|
}
|
|
|
|
// AppendNode implements the Noder interface.
|
|
func (n *localNoder) AppendNode(node *Node) {
|
|
n.nodes = append(n.nodes, node)
|
|
|
|
// All hosts must be merged in the same order on all nodes in the cluster.
|
|
sort.Sort(ByID(n.nodes))
|
|
}
|
|
|
|
// RemoveNode implements the Noder interface.
|
|
func (n *localNoder) RemoveNode(nodeID string) bool {
|
|
i := NodePositionByID(n.nodes, nodeID)
|
|
if i < 0 {
|
|
return false
|
|
}
|
|
|
|
copy(n.nodes[i:], n.nodes[i+1:])
|
|
n.nodes[len(n.nodes)-1] = nil
|
|
n.nodes = n.nodes[:len(n.nodes)-1]
|
|
|
|
return true
|
|
}
|