Fix issues found in Storage Hammer

conanfile.py

@@ -9,7 +9,7 @@
 
 class HomestoreConan(ConanFile):
     name = "homestore"
-    version = "7.3.3"
+    version = "7.3.4"
 
     homepage = "https://github.com/eBay/Homestore"
     description = "HomeStore Storage Engine"

src/lib/logstore/log_store.cpp

@@ -360,18 +360,21 @@ bool HomeLogStore::rollback(logstore_seq_num_t to_lsn) {
     incr_pending_request_num();
     // Fast path
     if (to_lsn == m_tail_lsn.load()) {
+        THIS_LOGSTORE_LOG(INFO, "Rollback to the current tail_lsn {}, no-op", to_lsn);
         decr_pending_request_num();
         return true;
     }
 
-    if (to_lsn > m_tail_lsn.load() || to_lsn < m_start_lsn.load()) {
+    // Special case: allow rollback to exactly start_lsn - 1.
+    // This handles the scenario where all logs were truncated and a leader switch happens before new logs commit.
+    if (to_lsn > m_tail_lsn.load() || to_lsn < m_start_lsn.load() - 1) {
         HS_LOG_ASSERT(false, "Attempted to rollback to {} which is not in the range of [{}, {}]", to_lsn,
-                      m_start_lsn.load(), m_tail_lsn.load());
+                      m_start_lsn.load() - 1, m_tail_lsn.load());
         decr_pending_request_num();
         return false;
     }
 
-    THIS_LOGSTORE_LOG(INFO, "Rolling back to {}, tail {}", to_lsn, m_tail_lsn.load());
+    THIS_LOGSTORE_LOG(INFO, "Rolling back to {}, start {} tail {}", to_lsn, m_start_lsn.load(), m_tail_lsn.load());
     bool do_flush{false};
     do {
         {

src/lib/logstore/log_store_service.cpp

@@ -309,7 +309,6 @@ void LogStoreService::remove_log_store(logdev_id_t logdev_id, logstore_id_t stor
     HS_LOG(INFO, logstore, "Removing logstore {} from logdev {}", store_id, logdev_id);
     incr_pending_request_num();
     folly::SharedMutexWritePriority::WriteHolder holder(m_logdev_map_mtx);
-    COUNTER_INCREMENT(m_metrics, logstores_count, 1);
     const auto it = m_id_logdev_map.find(logdev_id);
     if (it == m_id_logdev_map.end()) {
         HS_LOG(WARN, logstore, "logdev id {} doesnt exist", logdev_id);
@@ -325,6 +324,7 @@ void LogStoreService::device_truncate() {
     // TODO: make device_truncate_under_lock return future and do collectAllFutures;
     if (is_stopping()) return;
     incr_pending_request_num();
+    folly::SharedMutexWritePriority::ReadHolder holder(m_logdev_map_mtx);
     for (auto& [id, logdev] : m_id_logdev_map) {
         HS_LOG(DEBUG, logstore, "Truncating logdev {}", id);
         logdev->truncate();

src/lib/replication/log_store/home_raft_log_store.cpp

@@ -187,8 +187,11 @@ void HomeRaftLogStore::write_at(ulong index, nuraft::ptr< nuraft::log_entry >& e
     // calls, but it is dangerous to set higher number.
     m_last_durable_lsn = -1;
 
-    m_log_store->append_async(sisl::io_blob{buf->data_begin(), uint32_cast(buf->size()), false /* is_aligned */},
-                              nullptr /* cookie */, [buf](int64_t, sisl::io_blob&, logdev_key, void*) {});
+    auto const appended_seq =
+        m_log_store->append_async(sisl::io_blob{buf->data_begin(), uint32_cast(buf->size()), false /* is_aligned */},
+                                  nullptr /* cookie */, [buf](int64_t, sisl::io_blob&, logdev_key, void*) {});
+    HS_REL_ASSERT_EQ(to_repl_lsn(appended_seq), static_cast< repl_lsn_t >(index),
+                     "write_at appended lsn mismatch: expected {} actual {}", index, to_repl_lsn(appended_seq));
 
     auto position_in_cache = index % m_log_entry_cache.size();
     {

src/tests/test_home_raft_logstore.cpp

@@ -66,6 +66,15 @@ class RaftLogStoreClient {
         ASSERT_EQ(m_rls->start_index(), m_start_lsn) << "Start Index not expected to be updated after insertion";
     }
 
+    void write_at_start_bounday_test(nuraft::ptr< nuraft::log_entry >& le) {
+        m_rls->write_at(m_start_lsn, le);
+        ASSERT_EQ(m_rls->entry_at(m_start_lsn)->get_term(), le->get_term());
+        m_next_lsn = m_start_lsn + 1;
+        ASSERT_EQ(m_rls->start_index(), m_start_lsn);
+        ASSERT_EQ(m_rls->last_index(), m_start_lsn);
+        ASSERT_EQ(m_rls->next_slot(), m_next_lsn);
+    }
+
     void rollback_test() {
         m_next_lsn = (m_next_lsn - m_start_lsn) / 2; // Rollback half of the current logs
         ++m_cur_term;
@@ -92,6 +101,13 @@ class RaftLogStoreClient {
         validate_all_logs();
     }
 
+    void compact_all_test() {
+        m_start_lsn = m_next_lsn;
+        m_rls->compact(m_next_lsn - 1);
+        ASSERT_EQ(m_rls->start_index(), m_next_lsn) << "Post compaction, start_index is invalid";
+        validate_all_logs();
+    }
+
     void pack_test(uint64_t from, int32_t cnt, pack_result_t& out_pack) {
         out_pack.actual_data = m_rls->pack(from, cnt);
         ASSERT_NE(out_pack.actual_data.get(), nullptr);
@@ -258,6 +274,24 @@ TEST_F(TestRaftLogStore, lifecycle_test) {
     this->m_follower_store.append_read_test(nrecords); // total_records in follower = 4000
 }
 
+TEST_F(TestRaftLogStore, write_at_start_boundary_test) {
+    LOGINFO("Step 1: Append some records and then compact all");
+    this->m_leader_store.append_read_test(2);
+    this->m_leader_store.compact_all_test();
+
+    LOGINFO("Step 2: Write at start boundary when no logs exist, expect allowed");
+    // no more logs exist, write_at at start boundary should be allowed
+    auto le = nuraft::cs_new< nuraft::log_entry >(5 /*term*/, nuraft::buffer::alloc(8));
+    le->get_buf().put("ALLOW");
+    this->m_leader_store.write_at_start_bounday_test(le);
+
+    LOGINFO("Step 3: Write at start boundary again, expect allowed");
+    // write_at start boundary again to make sure rollback is allowed
+    le = nuraft::cs_new< nuraft::log_entry >(6 /*term*/, nuraft::buffer::alloc(8));
+    le->get_buf().put("ALLOW2");
+    this->m_leader_store.write_at_start_bounday_test(le);
+}
+
 SISL_OPTIONS_ENABLE(logging, test_home_raft_log_store, iomgr, test_common_setup)
 SISL_OPTION_GROUP(test_home_raft_log_store,
                   (num_records, "", "num_records", "number of record to test",