1. Introduce
leo_redundant_manager
Yosuke Hara @yosukehara
May, 2014

2. storage_0
storage_1
storage_2
[ Actual Nodes ]
RING
2 ^ 128
# of replicas = 3
0
2^128 -1
clock-wise
Filename = “bucket/leofs.key”
Hash = crypto:md5(Filename)
Primary node
Secondary(1) node
Secondary(2) node
“Virtual nodes”
[Actual Node : Virtual node = 1 : 128]
- For restrain unbalanced disc-usage and transaction (requests from gateways)
- For restrain effect of data-rebalance
Redundant-Manager 1/2
2
Primary node
Secondary(1) node
Secondary(2) node
Object of Replica-nodes
1 “Consisten-hashing”

3. storage_0
storage_1
storage_2
[ Actual Nodes ]
RING
2 ^ 128
# of replicas = 3
0
2^128 -1
“Virtual nodes”
[Actual Node : Virtual node = 1 : 128]
- For restrain unbalanced disc-usage and transaction (requests from gateways)
- For restrain effect of data-rebalance
Redundant-Manager 2/2
storage_3
Filename = “bucket/leofs.key”
Hash = crypto:md5(Filename)
clock-wise
Primary node
Secondary(1) node
Secondary(2) node
2
Primary node
Secondary(1) node
Secondary(2) node
Object of Replica-nodes
an attached node
Primary node
Secondary(1) node
Secondary(2) node
Object of Replica-nodes
<before>
<after>
1 “Consisten-hashing”