Fix stale log index when there is an snapshot but no log in disk

src/Service/NuRaftLogSegment.cpp

@@ -706,13 +706,11 @@ int NuRaftLogSegment::truncate(const UInt64 last_index_kept)
     return ret;
 }
 
-ptr<LogSegmentStore> LogSegmentStore::segment_store = nullptr;
-
 ptr<LogSegmentStore> LogSegmentStore::getInstance(const String & log_dir_, bool force_new)
 {
+    static ptr<LogSegmentStore> segment_store;
     if (segment_store == nullptr || force_new)
         segment_store = cs_new<LogSegmentStore>(log_dir_);
-
     return segment_store;
 }
 

src/Service/NuRaftLogSegment.h

@@ -239,7 +239,7 @@ class NuRaftLogSegment
 class LogSegmentStore
 {
 public:
-    using SegmentVector = std::vector<ptr<NuRaftLogSegment>>;
+    using Segments = std::vector<ptr<NuRaftLogSegment>>;
 
     static constexpr UInt32 MAX_SEGMENT_FILE_SIZE = 1000 * 1024 * 1024; //1G, 0.3K/Log, 3M logs
     static constexpr UInt32 MAX_SEGMENT_COUNT = 50; //50G
@@ -296,7 +296,7 @@ class LogSegmentStore
     int reset(UInt64 next_log_index);
 
     /// get closed segments
-    SegmentVector & getClosedSegments() { return segments; }
+    Segments & getClosedSegments() { return segments; }
 
     /// get file format version
     LogVersion getVersion(UInt64 index);
@@ -312,9 +312,6 @@ class LogSegmentStore
     /// find segment by log index
     int getSegment(UInt64 log_index, ptr<NuRaftLogSegment> & ptr);
 
-    /// global instance
-    static ptr<LogSegmentStore> segment_store;
-
     /// file log store directory
     String log_dir;
 
@@ -331,7 +328,7 @@ class LogSegmentStore
     Poco::Logger * log;
 
     /// closed segments
-    SegmentVector segments;
+    Segments segments;
 
     /// open segments
     ptr<NuRaftLogSegment> open_segment;

src/Service/NuRaftStateMachine.cpp

@@ -87,7 +87,7 @@ NuRaftStateMachine::NuRaftStateMachine(
     {
         LOG_INFO(log, "No previous last commit idx found, skip replaying logs.");
     }
-    else if (previous_last_commit_id < last_committed_idx)
+    else if (previous_last_commit_id <= last_committed_idx)
     {
         LOG_WARNING(
             log,

tests/integration/test_snapshots/test.py

@@ -1,6 +1,7 @@
 import os
 import random
 import string
+import time
 
 import pytest
 
@@ -72,6 +73,7 @@ def test_state_after_restart(started_cluster, node):
     finally:
         close_zk_clients([node_zk, node_zk2])
 
+
 @pytest.mark.parametrize(
     'node',
     [
@@ -115,3 +117,28 @@ def test_ephemeral_after_restart(started_cluster, node):
         assert list(sorted(existing_children)) == list(sorted(node_zk2.get_children("/test_ephemeral_after_restart")))
     finally:
         close_zk_clients([node_zk, node_zk2])
+
+
+@pytest.mark.parametrize(
+    'node',
+    [
+        cluster.add_instance('node5', main_configs=['configs/enable_keeper.xml'], with_zookeeper=True, stay_alive=True),
+        cluster.add_instance('node6', main_configs=['configs/enable_async_snapshot_keeper.xml'], with_zookeeper=True, stay_alive=True)
+    ]
+)
+def test_restart_with_no_log(started_cluster, node):
+    node_zk = node_zk2 = None
+    try:
+        node_zk = node.get_fake_zk()
+        node_zk.create("/test_restart_with_no_log", b"somevalue")
+
+        node.send_4lw_cmd(cmd="csnp")
+        time.sleep(1) # wait for snapshot to be taken
+
+        node.restart_raftkeeper(kill=True)
+        node.wait_for_join_cluster()
+
+        node_zk2 = node.get_fake_zk()
+        assert node_zk2.exists("/test_restart_with_no_log")
+    finally:
+        close_zk_clients([node_zk, node_zk2])