raftdb

• from geekbang course: <分布式协议与算法实战> https://time.geekbang.org/column/intro/279
  • https://www.yuque.com/hxzhouh/lcgsuz/lu71ec
  • <基于Raft的分布式KV系统开发实战>
• first run
  • go build to build raftdb executable.

  # fxrc @ popos in ~/SourceCode/raftdb-geekbang on git:main x [23:04:38] C:2
  $ ./raftdb -id node01 ~/.raftdb
  
  2021-05-26T23:04:54.177-0700 [INFO]  raft: initial configuration: index=0 servers=[]
  [store] 2021/05/26 23:04:54 bootstrap needed
  2021-05-26T23:04:54.177-0700 [INFO]  raft: entering follower state: follower="Node at 127.0.0.1:8089 [Follower]" leader=
  2021/05/26 23:04:54 no join addresses set
  2021-05-26T23:04:55.628-0700 [WARN]  raft: heartbeat timeout reached, starting election: last-leader=
  2021-05-26T23:04:55.628-0700 [INFO]  raft: entering candidate state: node="Node at 127.0.0.1:8089 [Candidate]" term=2
  2021-05-26T23:04:55.634-0700 [DEBUG] raft: votes: needed=1
  2021-05-26T23:04:55.634-0700 [DEBUG] raft: vote granted: from=node01 term=2 tally=1
  2021-05-26T23:04:55.634-0700 [INFO]  raft: election won: tally=1
  2021-05-26T23:04:55.634-0700 [INFO]  raft: entering leader state: leader="Node at 127.0.0.1:8089 [Leader]"
  [store] 2021/05/26 23:04:55 waiting for up to 2m0s for application of initial logs
  2021/05/26 23:04:55 raftdb started successfully
  

---

raftdb is a simple distributed key value store based on the Raft consensus protocol. It can be run on Linux, OSX, and Windows.

Running raftdb

Building raftdb requires Go 1.9 or later. gvm is a great tool for installing and managing your versions of Go.

Starting and running a raftdb cluster is easy. Download raftdb like so:

go get github.com/hanj4096/raftdb

Build raftdb like so:

cd $GOPATH/src/github.com/hanj4096/raftdb
go install

Bring up a cluster

Run your first raftdb node like so:

$GOPATH/bin/raftdb -id node01  -haddr raft-cluster-host01:8091 -raddr raft-cluster-host01:8089 ~/.raftdb

Let's bring up 2 more nodes, so we have a 3-node cluster. That way we can tolerate the failure of 1 node:

$GOPATH/bin/raftdb -id node02 -haddr raft-cluster-host02:8091 -raddr raft-cluster-host02:8089 -join raft-cluster-host01:8091 ~/.raftdb

$GOPATH/bin/raftdb -id node03 -haddr raft-cluster-host03:8091 -raddr raft-cluster-host03:8089 -join raft-cluster-host01:8091 ~/.raftdb

Reading and writing keys

You can now set a key and read its value back:

curl -X POST raft-cluster-host01:8091/key -d '{"foo": "bar"}' -L
curl -X GET raft-cluster-host01:8091/key/foo -L

You can now delete a key and its value:

curl -X DELETE raft-cluster-host02:8091/key/foo -L

Three read consistency level

You can now read the key's value by different read consistency level:

curl -X GET raft-cluster-host02:8091/key/foo?level=stale
curl -X GET raft-cluster-host02:8091/key/foo?level=default  -L
curl -X GET raft-cluster-host02:8091/key/foo?level=consistent  -L