forked from Deuxfleurs/garage
precisions
This commit is contained in:
parent
fdf908e845
commit
0522983aec
1 changed files with 7 additions and 5 deletions
|
@ -8,7 +8,7 @@ I have conducted a quick study of different methods to load-balance data over di
|
|||
|
||||
- *minimal disruption*: when adding or removing a node, as few partitions as possible should have to move around
|
||||
|
||||
- *order-agnostic*: the same set of nodes (associated with a datacenter name
|
||||
- *order-agnostic*: the same set of nodes (each associated with a datacenter name
|
||||
and a capacity) should always return the same distribution of partition
|
||||
replicas, independently of the order in which nodes were added/removed (this
|
||||
is to keep the implementation simple)
|
||||
|
@ -19,10 +19,12 @@ I have conducted a quick study of different methods to load-balance data over di
|
|||
|
||||
This strategy can be used with any ring-like algorithm to make it aware of the *multi-datacenter* requirement:
|
||||
|
||||
- the ring is a list of positions, each associated with a single node in the cluster
|
||||
- look up position of item on ring
|
||||
- select the node for that position
|
||||
- go clockwise, skipping nodes that:
|
||||
In this method, the ring is a list of positions, each associated with a single node in the cluster.
|
||||
Partitions contain all the keys between two consecutive items of the ring.
|
||||
To find the nodes that store replicas of a given partition:
|
||||
|
||||
- select the node for the position of the partition's lower bound
|
||||
- go clockwise on the ring, skipping nodes that:
|
||||
- we halve already selected
|
||||
- are in a datacenter of a node we have selected, except if we already have nodes from all possible datacenters
|
||||
|
||||
|
|
Loading…
Reference in a new issue