add lsn check before append entry

conanfile.py

@@ -9,7 +9,7 @@
 
 class HomestoreConan(ConanFile):
     name = "homestore"
-    version = "6.4.54"
+    version = "6.4.55"
 
     homepage = "https://github.com/eBay/Homestore"
     description = "HomeStore Storage Engine"

src/lib/replication/log_store/home_raft_log_store.cpp

@@ -262,10 +262,12 @@ raft_buf_ptr_t HomeRaftLogStore::pack(ulong index, int32_t cnt) {
     m_log_store->foreach (
         to_store_lsn(index),
         [this, &out_buf, &remain_cnt]([[maybe_unused]] store_lsn_t cur, const log_buffer& entry) mutable -> bool {
+            size_t const total_entry_size = entry.size() + sizeof(uint32_t);
             if (remain_cnt-- > 0) {
                 size_t avail_size = out_buf->size() - out_buf->pos();
-                if (avail_size < entry.size() + sizeof(uint32_t)) {
-                    avail_size += std::max(out_buf->size() * 2, (size_t)entry.size() + sizeof(uint32_t));
+                // available size of packing buffer should be able to hold entry.size() and the length of this entry
+                if (avail_size < total_entry_size) {
+                    avail_size += std::max(out_buf->size() * 2, total_entry_size);
                     out_buf = nuraft::buffer::expand(*out_buf, avail_size);
                 }
                 REPL_STORE_LOG(TRACE, "packing lsn={} of size={}, avail_size in buffer={}", to_repl_lsn(cur),

src/lib/replication/repl_dev/raft_repl_dev.cpp

@@ -526,7 +526,7 @@ void RaftReplDev::check_and_fetch_remote_data(std::vector< repl_req_ptr_t > rreq
 void RaftReplDev::fetch_data_from_remote(std::vector< repl_req_ptr_t > rreqs) {
     if (rreqs.size() == 0) { return; }
 
-    std::vector<::flatbuffers::Offset< RequestEntry > > entries;
+    std::vector< ::flatbuffers::Offset< RequestEntry > > entries;
     entries.reserve(rreqs.size());
 
     shared< flatbuffers::FlatBufferBuilder > builder = std::make_shared< flatbuffers::FlatBufferBuilder >();
@@ -1041,6 +1041,12 @@ std::pair< bool, nuraft::cb_func::ReturnCode > RaftReplDev::handle_raft_event(nu
                 entries.size(), raft_req->get_last_log_term(), start_lsn, start_lsn + entries.size() - 1,
                 m_commit_upto_lsn.load(), raft_req->get_commit_idx());
 
+        if (start_lsn != m_data_journal->next_slot()) {
+            // if the start_lsn of this batch does not match the next_slot, drop this log batch
+            // this will happen when the leader is sending the logs which are already received and appended
+            return {true, nuraft::cb_func::ReturnCode::ReturnNull};
+        }
+
         if (!entries.empty()) {
             RD_LOGT("Raft channel: Received {} append entries on follower from leader, localizing them",
                     entries.size());
@@ -1050,13 +1056,7 @@ std::pair< bool, nuraft::cb_func::ReturnCode > RaftReplDev::handle_raft_event(nu
                 if (entry->get_val_type() != nuraft::log_val_type::app_log) { continue; }
                 if (entry->get_buf_ptr()->size() == 0) { continue; }
                 auto req = m_state_machine->localize_journal_entry_prepare(*entry);
-                // TODO :: we need to indentify whether this log entry should be appended to log store.
-                // 1 for lsn, if the req#lsn is not -1, it means this log has been localized and apeneded before, we
-                // should skip it.
-                // 2 for dsn, if the req#dsn is less than the next_dsn, it means this log has been
-                // committed, we should skip it.
-                // here, we only check the first condition for now. revisit here if we need to check the second
-                if (req == nullptr || req->lsn() != -1) {
+                if (req == nullptr) {
                     sisl::VectorPool< repl_req_ptr_t >::free(reqs);
                     return {true, nuraft::cb_func::ReturnCode::ReturnNull};
                 }

src/tests/test_raft_repl_dev.cpp

@@ -432,7 +432,7 @@ class RaftReplDevTest : public testing::Test {
                 // destroyed for ever. we need handle this in raft_repl_dev. revisit here after making changes at
                 // raft_repl_dev side to hanle this case. this is a workaround to avoid the infinite loop for now.
                 if (i++ > 10 && !force_leave) {
-                    LOGWARN("Waiting for repl dev to get destroyed and it is leader, so do a force leave");
+                    LOGWARN("has already waited for repl dev to get destroyed for 10 times, so do a force leave");
                     repl_dev->force_leave();
                     force_leave = true;
                 }