fix get peer info (#107)

1 Fix a bug where a peer does not exist in the configuration of the leader.

For the remove_member case, the leader will first remove the member from the peer_list, and then apply the new cluster configuration which excludes the removed member. If a leader gets the peer_list before the to-be-removed node is removed from the peer_list, and then tries to get_srv_config after the node is removed for the cluster config (new config is applied), it cannot find this peer in the configuration.

2 Support follower to get its own peer info, which is useful for the upper layer to get the last appended log index of a follower.

conanfile.py

@@ -10,7 +10,7 @@
 
 class NuRaftMesgConan(ConanFile):
     name = "nuraft_mesg"
-    version = "3.6.2"
+    version = "3.6.3"
 
     homepage = "https://github.com/eBay/nuraft_mesg"
     description = "A gRPC service for NuRAFT"

src/lib/repl_service_ctx.cpp

@@ -89,24 +89,35 @@ const std::string& repl_service_ctx::raft_leader_id() const {
 
 std::vector< peer_info > repl_service_ctx::get_raft_status() const {
     std::vector< peer_info > peers;
-    if (!is_raft_leader()) return peers;
     if (!_server) return peers;
 
-    auto pinfo_all = _server->get_peer_info_all();
-    // add leader to the list
-    nuraft::raft_server::peer_info pi_leader;
-    pi_leader.id_ = _server->get_id();
-    pi_leader.last_log_idx_ = _server->get_last_log_idx();
-    pinfo_all.emplace_back(pi_leader);
-
-    for (auto const& pinfo : pinfo_all) {
-        std::string_view peer_id;
-        if (auto srv_config = _server->get_srv_config(pinfo.id_); nullptr != srv_config) {
-            peer_id = srv_config->get_endpoint();
+    if (is_raft_leader()) {
+        // leader can get all the peer info
+        auto pinfo_all = _server->get_peer_info_all();
+        // get all the peer info except the leader
+        for (auto const& pinfo : pinfo_all) {
+            std::string_view peer_id;
+            if (auto srv_config = _server->get_srv_config(pinfo.id_); nullptr != srv_config) {
+                peer_id = srv_config->get_endpoint();
+            }
+            if (peer_id.empty()) {
+                // if remove_member case , leader will first remove the member from peer_list, and then apply the new
+                // cluster configuraiton which excludes the removed member, so there is case that the peer_id is not in
+                // the config of leader.
+                LOGW("do not find peer id  {} in the conifg of leader", pinfo.id_);
+                continue;
+            }
+            peers.emplace_back(peer_info{std::string(peer_id), pinfo.last_log_idx_, pinfo.last_succ_resp_us_});
         }
-        DEBUG_ASSERT(!peer_id.empty(), "Unknown peer in config");
-        peers.emplace_back(peer_info{std::string(peer_id), pinfo.last_log_idx_, pinfo.last_succ_resp_us_});
     }
+
+    auto my_id = _server->get_id();
+    auto my_peer_id = _server->get_srv_config(my_id)->get_endpoint();
+
+    // add the peer info of itself(leader or follower) , which is useful for upper layer
+    // from the view a node itself, last_succ_resp_us_ make no sense, so set it to 0
+    peers.emplace_back(my_peer_id, _server->get_last_log_idx(), 0);
+
     return peers;
 }
 

src/tests/data_service_tests.cpp

@@ -94,7 +94,6 @@ TEST_F(DataServiceFixture, BasicTest1) {
             return folly::Unit();
         }));
 
-
     auto repl_ctx1 = sm1->get_repl_context();
     for (auto svr : repl_ctx1->_server->get_config()->get_servers()) {
         if (svr->get_endpoint() == to_string(app_1_->id_)) continue;
@@ -113,25 +112,26 @@ TEST_F(DataServiceFixture, BasicTest1) {
     io_blob_list_t big_cli_buf;
     test_state_mgr::fill_data_vec_big(big_cli_buf, 4 * 1024 * 1024);
     sm1->data_service_request_unidirectional(nuraft_mesg::role_regex::ALL, SEND_DATA, big_cli_buf)
-                          .deferValue([](auto e) -> NullResult {
-                              EXPECT_TRUE(e.hasValue());
-                              return folly::Unit();
-                          }).get();
+        .deferValue([](auto e) -> NullResult {
+            EXPECT_TRUE(e.hasValue());
+            return folly::Unit();
+        })
+        .get();
     LOGINFO("End large object write test")
     LOGINFO("Starting large object read test")
 
     sm4_1->data_service_request_bidirectional(nuraft_mesg::role_regex::LEADER, REQUEST_DATA, big_cli_buf)
-                          .deferValue([](auto e) -> NullResult {
-                              EXPECT_TRUE(e.hasValue());
-			      test_state_mgr::verify_data(e.value().response_blob());
-                              return folly::Unit();
-                          }).get();
+        .deferValue([](auto e) -> NullResult {
+            EXPECT_TRUE(e.hasValue());
+            test_state_mgr::verify_data(e.value().response_blob());
+            return folly::Unit();
+        })
+        .get();
     LOGINFO("End large object read test")
     for (auto& buf : big_cli_buf) {
         buf.buf_free();
     }
 
-
     // add a new member to data_service_test_group and check if repl_ctx4 sends data to newly added member
     auto add_3 = app_4->instance_->add_member(data_group, app_3_->id_);
     std::this_thread::sleep_for(std::chrono::seconds(1));
@@ -180,12 +180,13 @@ TEST_F(DataServiceFixture, BasicTest2) {
     auto repl_ctx_2 = app_2_->state_mgr_map_[group_id_]->get_repl_context();
     EXPECT_TRUE(repl_ctx_2 && !repl_ctx_2->is_raft_leader());
     EXPECT_TRUE(repl_ctx_2 && repl_ctx_2->raft_leader_id() == to_string(app_1_->id_));
-    EXPECT_TRUE(repl_ctx && repl_ctx_2->get_raft_status().size() == 0);
+    // if it`s a follower, it should have only one peer info of itself
+    EXPECT_TRUE(repl_ctx && repl_ctx_2->get_raft_status().size() == 1);
 
     auto repl_ctx_3 = app_3_->state_mgr_map_[group_id_]->get_repl_context();
     EXPECT_TRUE(repl_ctx_3 && !repl_ctx_3->is_raft_leader());
     EXPECT_TRUE(repl_ctx_3 && repl_ctx_3->raft_leader_id() == to_string(app_1_->id_));
-    EXPECT_TRUE(repl_ctx && repl_ctx_3->get_raft_status().size() == 0);
+    EXPECT_TRUE(repl_ctx && repl_ctx_3->get_raft_status().size() == 1);
 
     std::list< nuraft_mesg::replica_config > cluster_config;
     repl_ctx->get_cluster_config(cluster_config);