mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2024-12-12 16:49:03 +08:00
59 lines
2.0 KiB
Plaintext
59 lines
2.0 KiB
Plaintext
1. each file can choose the replication factor
|
|
2. replication granularity is in volume level
|
|
3. if not enough spaces, we can automatically decrease some volume's the replication factor, especially for cold data
|
|
4. support migrating data to cheaper storage
|
|
5. manual volume placement, access-based volume placement, auction based volume placement
|
|
|
|
When a new volume server is started, it reports
|
|
1. how many volumes it can hold
|
|
2. current list of existing volumes
|
|
Each volume server remembers:
|
|
1. current volume ids, replica locations
|
|
|
|
The master assign volume ids based on
|
|
1. replication factor
|
|
data center, rack
|
|
2. concurrent write support
|
|
On master, stores the replication configuration
|
|
{
|
|
replication:{
|
|
{factor:1, min_volume_count:3, weight:10},
|
|
{factor:2, min_volume_count:2, weight:20},
|
|
{factor:3, min_volume_count:3, weight:30}
|
|
},
|
|
port:9333,
|
|
|
|
}
|
|
Or manually via command line
|
|
1. add volume with specified replication factor
|
|
2. add volume with specified volume id
|
|
|
|
|
|
If duplicated volume ids are reported from different volume servers,
|
|
the master determines the replication factor of the volume,
|
|
if less than the replication factor, the volume is in readonly mode
|
|
if more than the replication factor, the volume will purge the smallest/oldest volume
|
|
if equal, the volume will function as usual
|
|
|
|
maybe use gossip to send the volumeServer~volumes information
|
|
|
|
|
|
Use cases:
|
|
on volume server
|
|
1. weed volume -mserver="xx.xx.xx.xx:9333" -publicUrl="good.com:8080" -dir="/tmp" -volumes=50
|
|
on weed master
|
|
1. weed master -port=9333
|
|
generate a default json configuration file if doesn't exist
|
|
|
|
Bootstrap
|
|
1. at the very beginning, the system has no volumes at all.
|
|
2. if maxReplicationFactor==1, always initialize volumes right away
|
|
3. if nServersHasFreeSpaces >= maxReplicationFactor, auto initialize
|
|
4. if maxReplicationFactor>1
|
|
weed shell
|
|
> disable_auto_initialize
|
|
> enable_auto_initialize
|
|
> assign_free_volume vid "server1:port","server2:port","server3:port"
|
|
> status
|
|
5.
|
|
|