[Tarantool-patches] [PATCH v2 9/8] replication: send current Raft term in join response

[Serge Petrenko via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Make Raft nodes send out their latest persisted term to joining
replicas.

Follow-up #6034

diff --git a/src/box/applier.cc b/src/box/applier.cc
index 9d90a2384..2b3c653a5 100644
--- a/src/box/applier.cc
+++ b/src/box/applier.cc
@@ -463,6 +463,11 @@ applier_wait_snapshot(struct applier *applier)
                         if (xrow_decode_synchro(&row, &req) != 0)
                                 diag_raise();
                         txn_limbo_process(&txn_limbo, &req);
+               } else if (iproto_type_is_raft_request(row.type)) {
+                       struct raft_request req;
+                       if (xrow_decode_raft(&row, &req, NULL) != 0)
+                               diag_raise();
+                       box_raft_recover(&req);
                 } else if (iproto_type_is_error(row.type)) {
                         xrow_decode_error_xc(&row);  /* rethrow error */
                 } else {
diff --git a/src/box/relay.cc b/src/box/relay.cc
index e05b53d5d..510e5c420 100644
--- a/src/box/relay.cc
+++ b/src/box/relay.cc
@@ -400,7 +400,9 @@ relay_initial_join(int fd, uint64_t sync, struct 
vclock *vclock)
                 diag_raise();

         struct synchro_request req;
+       struct raft_request raft_req;
         txn_limbo_checkpoint(&txn_limbo, &req);
+       box_raft_checkpoint_local(&raft_req);

         /* Respond to the JOIN request with the current vclock. */
         struct xrow_header row;
@@ -419,6 +421,11 @@ relay_initial_join(int fd, uint64_t sync, struct 
vclock *vclock)
                 row.sync = sync;
                 coio_write_xrow(&relay->io, &row);
         }
+       if (raft_req.term > 1) {
+               xrow_encode_raft(&row, &fiber()->gc, &raft_req);
+               row.sync = sync;
+               coio_write_xrow(&relay->io, &row);
+       }

         /* Send read view to the replica. */
         engine_join_xc(&ctx, &relay->stream);