Moving to github https://github.com/chrislusf/weed-fs/wiki

How to use Replication

Introduction

Weed-FS can support replication. The replication is implemented not on file level, but on volume level.

How to use Replication

Basically, the way it works is:

1. start weed master, and optionally specify the default replication type ./weed master -defaultReplicationType=001
2. start volume servers as this: ./weed volume -port=8081 -dir=/tmp/1 -max=100 ./weed volume -port=8082 -dir=/tmp/2 -max=100 ./weed volume -port=8083 -dir=/tmp/3 -max=100

Submitting, Reading, Deleting files has the same steps.

The meaning of replication type

Note: This subject to change.

000: no replication, just one copy 001: replicate once on the same rack 010: replicate once on a different rack in the same data center 100: replicate once on a different data center 200: replicate twice on two other different data center 110: replicate once on a different rack, and once on a different data center ...

So if the replication type is xyz x: number of replica in other data centers y: number of replica in other racks in the same data center z: number of replica in other servers in the same rack

x,y,z each can be 0, 1, or 2. So there are 27 possible replication types, and can be easily extended. Each replication type will physically create x+y+z+1 copies of volume data files.

Example Topology Configuration File

The WeedFS master server tries to read the topology configuration file. It default to /etc/weedfs/weedfs.conf if not specified. The topology setting to configure data center and racks file format is as this. <Configuration> <Topology> <DataCenter name="dc1"> <Rack name="rack1"> <Ip>192.168.1.1</Ip> </Rack> </DataCenter> <DataCenter name="dc2"> <Rack name="rack1"> <Ip>192.168.1.2</Ip> </Rack> <Rack name="rack2"> <Ip>192.168.1.3</Ip> <Ip>192.168.1.4</Ip> </Rack> </DataCenter> </Topology> </Configuration>

Configure Topology via Volume Server

Instead of the weed.conf file, volume servers can start with a specific data center name. weed volume -dir=/tmp/1 -port=8080 -dataCenter=dc1 weed volume -dir=/tmp/2 -port=8081 -dataCenter=dc2

Allocate File Key on specific data center

When requesting a file key, an optional "dataCenter" parameter can limit the assigned volume to the specific data center. For example, this specify http://localhost:9333/dir/assign?dataCenter=dc1