raft.cluster api returns error if no leader is there in the network in version 2.4.0

docs/Consensus/raft/raft-rpc-api.md

@@ -0,0 +1,192 @@
+# Raft RPC API
+# APIs
+### raft_cluster
+Returns the details of all nodes part of the raft cluster
+#### Parameters
+None
+#### Returns
+* `hostName`: DNS name or the host IP address 
+* `nodeActive`: true if the node is active in raft cluster else false
+* `nodeId`: enode id of the node
+* `p2pPort`: p2p port 
+* `raftId`: raft id of the node
+* `raftPort`: raft port 
+* `role`: role of the node in raft quorum. Can be minter/ verifier/ learner. In case there is no leader at network level it will be returned as `""`
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_cluster", "id":10}' --header "Content-Type: application/json"
+
+// Response
+{"jsonrpc":"2.0","id":10,"result":[{"raftId":1,"nodeId":"ac6b1096ca56b9f6d004b779ae3728bf83f8e22453404cc3cef16a3d9b96608bc67c4b30db88e0a5a6c6390213f7acbe1153ff6d23ce57380104288ae19373ef","p2pPort":21000,"raftPort":50401,"hostname":"127.0.0.1","role":"minter","nodeActive":true},{"raftId":3,"nodeId":"579f786d4e2830bbcc02815a27e8a9bacccc9605df4dc6f20bcc1a6eb391e7225fff7cb83e5b4ecd1f3a94d8b733803f2f66b7e871961e7b029e22c155c3a778","p2pPort":21002,"raftPort":50403,"hostname":"127.0.0.1","role":"verifier","nodeActive":true},{"raftId":2,"nodeId":"0ba6b9f606a43a95edc6247cdb1c1e105145817be7bcafd6b2c0ba15d58145f0dc1a194f70ba73cd6f4cdd6864edc7687f311254c7555cc32e4d45aeb1b80416","p2pPort":21001,"raftPort":50402,"hostname":"127.0.0.1","role":"verifier","nodeActive":true}]}
+```
+
+```javascript tab="geth console"
+> raft.cluster
+[{
+    hostname: "127.0.0.1",
+    nodeActive: true,
+    nodeId: "0ba6b9f606a43a95edc6247cdb1c1e105145817be7bcafd6b2c0ba15d58145f0dc1a194f70ba73cd6f4cdd6864edc7687f311254c7555cc32e4d45aeb1b80416",
+    p2pPort: 21001,
+    raftId: 2,
+    raftPort: 50402,
+    role: "verifier"
+}, {
+    hostname: "127.0.0.1",
+    nodeActive: true,
+    nodeId: "579f786d4e2830bbcc02815a27e8a9bacccc9605df4dc6f20bcc1a6eb391e7225fff7cb83e5b4ecd1f3a94d8b733803f2f66b7e871961e7b029e22c155c3a778",
+    p2pPort: 21002,
+    raftId: 3,
+    raftPort: 50403,
+    role: "verifier"
+}, {
+    hostname: "127.0.0.1",
+    nodeActive: true,
+    nodeId: "ac6b1096ca56b9f6d004b779ae3728bf83f8e22453404cc3cef16a3d9b96608bc67c4b30db88e0a5a6c6390213f7acbe1153ff6d23ce57380104288ae19373ef",
+    p2pPort: 21000,
+    raftId: 1,
+    raftPort: 50401,
+    role: "minter"
+}]
+```
+### raft_role 
+Returns the role of the current node in raft cluster
+#### Parameters
+None
+#### Returns
+* `result`: role of the node in raft cluster. Can be minter/ verifier/ learner. In case there is no leader at network level it will be returned as `""`
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_role", "id":10}' --header "Content-Type: application/json"
+
+// Response
+{"jsonrpc":"2.0","id":10,"result":"verifier"}
+```
+
+```javascript tab="geth console"
+> raft.role
+"minter"
+```
+### raft_leader
+Returns enode id of the leader node
+#### Parameters
+None
+#### Returns
+* `result`: enode id of the leader
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_leader", "id":10}' --header "Content-Type: application/json"
+
+// Response
+{"jsonrpc":"2.0","id":10,"result":"ac6b1096ca56b9f6d004b779ae3728bf83f8e22453404cc3cef16a3d9b96608bc67c4b30db88e0a5a6c6390213f7acbe1153ff6d23ce57380104288ae19373ef"}
+```
+
+
+```javascript tab="geth console"
+> raft.leader
+"ac6b1096ca56b9f6d004b779ae3728bf83f8e22453404cc3cef16a3d9b96608bc67c4b30db88e0a5a6c6390213f7acbe1153ff6d23ce57380104288ae19373ef"
+```
+
+If there is no leader at the network level, the call to the api will result in the following error:
+```javascript
+> raft.leader
+Error: no leader is currently elected
+    at web3.js:3143:20
+    at web3.js:6347:15
+    at get (web3.js:6247:38)
+    at <unknown>
+```
+
+### raft_addPeer
+API for adding a new peer to the network. 
+#### Parameters
+* `enodeId`: enode id of the node to be added to the network
+#### Returns
+* `result`: raft id for the node being added
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_addPeer","params": ["enode://3701f007bfa4cb26512d7df18e6bbd202e8484a6e11d387af6e482b525fa25542d46ff9c99db87bd419b980c24a086117a397f6d8f88e74351b41693880ea0cb@127.0.0.1:21004?discport=0&raftport=50405"], "id":10}' --header "Content-Type: application/json"
+
+// Response
+{"jsonrpc":"2.0","id":10,"result":5}
+```
+
+```javascript tab="geth console"
+> raft.addPeer("enode://3701f007bfa4cb26512d7df18e6bbd202e8484a6e11d387af6e482b525fa25542d46ff9c99db87bd419b980c24a086117a397f6d8f88e74351b41693880ea0cb@127.0.0.1:21004?discport=0&raftport=50405")
+5
+```
+
+The new node can join the network with `geth` option of `--raftjoinexisting <<raftId>>`
+
+If the node being added is already part of the network the of the network, the following error is thrown:
+```javascript
+> raft.addPeer("enode://3701f007bfa4cb26512d7df18e6bbd202e8484a6e11d387af6e482b525fa25542d46ff9c99db87bd419b980c24a086117a397f6d8f88e74351b41693880ea0cb@127.0.0.1:21004?discport=0&raftport=50405")
+Error: node with this enode has already been added to the cluster: f06c06f1e958cb2edf90d8bfb912de287f9b047b4228436e94b5b78e3ee16171
+    at web3.js:3143:20
+    at web3.js:6347:15
+    at web3.js:5081:36
+    at <anonymous>:1:1
+```
+### raft_removePeer
+API to remove a node from raft cluster
+#### Parameters
+* `raftId` : raft id of  the node to be removed from the cluster
+#### Returns
+* `result`: null
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_removePeer","params": [4], "id":10}' --header "Content-Type: application/json"
+
+// Response
+{"jsonrpc":"2.0","id":10,"result":null}
+```
+
+```javascript tab="geth console"
+> raft.removePeer(4)
+null
+```
+
+### raft_addLearner
+API to add a new node to the network as a learner node. The learner node syncs with network and can transact but will not be part of raft quorum and hence will not provide block confirmation to minter node. 
+#### Parameters
+* `enodeId`
+#### Returns
+* `result`: raft id for the node being added
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_addLearner","params": ["enode://3701f007bfa4cb26512d7df18e6bbd202e8484a6e11d387af6e482b525fa25542d46ff9c99db87bd419b980c24a086117a397f6d8f88e74351b41693880ea0cb@127.0.0.1:21004?discport=0&raftport=50405"], "id":10}' --header "Content-Type: application/json"
+
+// Response
+{"jsonrpc":"2.0","id":10,"result":5}
+
+```
+
+```javascript tab="geth console"
+> raft.addLearner("enode://3701f007bfa4cb26512d7df18e6bbd202e8484a6e11d387af6e482b525fa25542d46ff9c99db87bd419b980c24a086117a397f6d8f88e74351b41693880ea0cb@127.0.0.1:21004?discport=0&raftport=50405")
+5
+```
+### raft_promoteToPeer
+API for promoting a learner node to peer and thus be part of the raft quorum. 
+#### Parameters
+* `raftId`: raft id of the node to be promoted
+#### Returns
+* `result`: true or false
+#### Examples
+```jshelllanguage tab="JSON RPC"
+// Request
+curl -X POST http://127.0.0.1:22001 --data '{"jsonrpc":"2.0","method":"raft_promoteToPeer","params": [4], "id":10}' --header "Content-Type: application/json"
+
+// Response
+{// Response
+ {"jsonrpc":"2.0","id":10,"result":true}
+```
+
+```javascript tab="geth console"
+> raft.promoteToPeer(4)
+true
+```

docs/Consensus/raft.md → docs/Consensus/raft/raft.md

@@ -1,4 +1,4 @@
-# Raft-based consensus for Ethereum/Quorum
+# Raft Consensus Overview
 
 ## Introduction
 
@@ -190,4 +190,4 @@ Note that like the enode IDs listed in the static peers JSON file, this enode ID
 
 ## FAQ
 
-Answers to frequently asked questions can be found on the main [Quorum FAQ page](../FAQ.md).
+Answers to frequently asked questions can be found on the main [Quorum FAQ page](../../FAQ.md).

mkdocs.yml

@@ -20,7 +20,9 @@ nav:
         - Quorum API: Getting Started/api.md
     - Consensus:
         - Consensus: Consensus/Consensus.md
-        - Raft: Consensus/raft.md
+        - Raft BFT:
+            - Consensus/raft/raft.md
+            - Consensus/raft/raft-rpc-api.md
         - Istanbul BFT:
             - Consensus/ibft/istanbul-rpc-api.md
             - Consensus/ibft/ibft-parameters.md

raft/api.go

@@ -1,5 +1,10 @@
 package raft
 
+import (
+	"errors"
+	"github.com/coreos/etcd/pkg/types"
+)
+
 type RaftNodeInfo struct {
 	ClusterSize    int        `json:"clusterSize"`
 	Role           string     `json:"role"`
@@ -19,22 +24,49 @@ func NewPublicRaftAPI(raftService *RaftService) *PublicRaftAPI {
 }
 
 func (s *PublicRaftAPI) Role() string {
+	if err := s.checkIfNodeInCluster(); err != nil {
+		return ""
+	}
+	_, err := s.raftService.raftProtocolManager.LeaderAddress()
+	if err != nil {
+		return ""
+	}
 	return s.raftService.raftProtocolManager.NodeInfo().Role
 }
 
+// helper function to check if self node is part of cluster
+func (s *PublicRaftAPI) checkIfNodeInCluster() error {
+	if s.raftService.raftProtocolManager.IsIDRemoved(uint64(s.raftService.raftProtocolManager.raftId)) {
+		return errors.New("node not part of raft cluster. operations not allowed")
+	}
+	return nil
+}
+
 func (s *PublicRaftAPI) AddPeer(enodeId string) (uint16, error) {
+	if err := s.checkIfNodeInCluster(); err != nil {
+		return 0, err
+	}
 	return s.raftService.raftProtocolManager.ProposeNewPeer(enodeId, false)
 }
 
 func (s *PublicRaftAPI) AddLearner(enodeId string) (uint16, error) {
+	if err := s.checkIfNodeInCluster(); err != nil {
+		return 0, err
+	}
 	return s.raftService.raftProtocolManager.ProposeNewPeer(enodeId, true)
 }
 
 func (s *PublicRaftAPI) PromoteToPeer(raftId uint16) (bool, error) {
+	if err := s.checkIfNodeInCluster(); err != nil {
+		return false, err
+	}
 	return s.raftService.raftProtocolManager.PromoteToPeer(raftId)
 }
 
 func (s *PublicRaftAPI) RemovePeer(raftId uint16) error {
+	if err := s.checkIfNodeInCluster(); err != nil {
+		return err
+	}
 	return s.raftService.raftProtocolManager.ProposePeerRemoval(raftId)
 }
 
@@ -48,33 +80,57 @@ func (s *PublicRaftAPI) Leader() (string, error) {
 }
 
 func (s *PublicRaftAPI) Cluster() ([]ClusterInfo, error) {
+	// check if the node has already been removed from cluster
+	// if yes return nil
+	if err := s.checkIfNodeInCluster(); err != nil {
+		return []ClusterInfo{}, nil
+	}
+
 	nodeInfo := s.raftService.raftProtocolManager.NodeInfo()
 	if nodeInfo.Role == "" {
 		return []ClusterInfo{}, nil
 	}
+
+	noLeader := false
 	leaderAddr, err := s.raftService.raftProtocolManager.LeaderAddress()
 	if err != nil {
-		if err == errNoLeaderElected && s.Role() == "" {
+		noLeader = true
+		if s.raftService.raftProtocolManager.NodeInfo().Role == "" {
 			return []ClusterInfo{}, nil
 		}
-		return []ClusterInfo{}, err
 	}
+
 	peerAddresses := append(nodeInfo.PeerAddresses, nodeInfo.Address)
 	clustInfo := make([]ClusterInfo, len(peerAddresses))
 	for i, a := range peerAddresses {
 		role := ""
-		if a.RaftId == leaderAddr.RaftId {
-			role = "minter"
-		} else if s.raftService.raftProtocolManager.isLearner(a.RaftId) {
-			role = "learner"
-		} else if s.raftService.raftProtocolManager.isVerifier(a.RaftId) {
-			role = "verifier"
+		if !noLeader {
+			if a.RaftId == leaderAddr.RaftId {
+				role = "minter"
+			} else if s.raftService.raftProtocolManager.isLearner(a.RaftId) {
+				role = "learner"
+			} else if s.raftService.raftProtocolManager.isVerifier(a.RaftId) {
+				role = "verifier"
+			}
 		}
-		clustInfo[i] = ClusterInfo{*a, role}
+		clustInfo[i] = ClusterInfo{*a, role, s.checkIfNodeIsActive(a.RaftId)}
 	}
 	return clustInfo, nil
 }
 
+// checkIfNodeIsActive checks if the raft node is active
+// if the raft node is active ActiveSince returns non-zero time
+func (s *PublicRaftAPI) checkIfNodeIsActive(raftId uint16) bool {
+	if raftId == s.raftService.raftProtocolManager.raftId {
+		return true
+	}
+		activeSince := s.raftService.raftProtocolManager.transport.ActiveSince(types.ID(raftId))
+	if activeSince.IsZero() {
+		return false
+	}
+	return true
+}
+
 func (s *PublicRaftAPI) GetRaftId(enodeId string) (uint16, error) {
 	return s.raftService.raftProtocolManager.FetchRaftId(enodeId)
 }

raft/peer.go

@@ -29,7 +29,8 @@ type Address struct {
 
 type ClusterInfo struct {
 	Address
-	Role string `json:"role"`
+	Role       string `json:"role"`
+	NodeActive bool   `json:"nodeActive"`
 }
 
 func newAddress(raftId uint16, raftPort int, node *enode.Node, withHostname bool) *Address {