diff --git a/mittest/logservice/test_ob_simple_log_basic_func.cpp b/mittest/logservice/test_ob_simple_log_basic_func.cpp
index ab027a375c..b9a662ab60 100644
--- a/mittest/logservice/test_ob_simple_log_basic_func.cpp
+++ b/mittest/logservice/test_ob_simple_log_basic_func.cpp
@@ -22,6 +22,7 @@
 #include "share/ob_errno.h"
 #define private public
 #include "logservice/palf/log_define.h"
+#include "logservice/palf/lsn_allocator.h"
 #include "share/scn.h"
 #include "logservice/palf/log_rpc_processor.h"
 #include "env/ob_simple_log_cluster_env.h"
@@ -76,6 +77,71 @@ TEST_F(TestObSimpleLogClusterBasicFunc, submit_log)
   PALF_LOG(INFO, "end test submit_log", K(id), K(guard));
 }
 
+// test_max_padding_size: 测试padding entry最长的场景(2M+16K+88+4K-1B).
+TEST_F(TestObSimpleLogClusterBasicFunc, test_max_padding_size)
+{
+  SET_CASE_LOG_FILE(TEST_NAME, "submit_log");
+  //OB_LOGGER.set_log_level("TRACE");
+  const int64_t id = ATOMIC_AAF(&palf_id_, 1);
+  const int64_t create_ts = 100;
+  share::SCN create_scn;
+  create_scn.convert_for_logservice(create_ts);
+  int64_t leader_idx = 0;
+  PalfHandleImplGuard leader;
+  ObTimeGuard guard("submit_log", 0);
+  EXPECT_EQ(OB_SUCCESS, create_paxos_group(id, create_scn, leader_idx, leader));
+  guard.click("create");
+  int64_t follower_1_idx = (leader_idx + 1) % ObSimpleLogClusterTestBase::member_cnt_;
+  int64_t follower_2_idx = (leader_idx + 2) % ObSimpleLogClusterTestBase::member_cnt_;
+  block_net(leader_idx, follower_1_idx);
+
+  const int64_t group_entry_header_total_size = LogGroupEntryHeader::HEADER_SER_SIZE + LogEntryHeader::HEADER_SER_SIZE;
+  const int64_t max_valid_group_entry_size = MAX_LOG_BODY_SIZE + group_entry_header_total_size;
+  // padding entry size上限如下，预期不会达到该值，故最大值应该是该值减1Byte
+  const int64_t max_padding_entry_size = max_valid_group_entry_size + CLOG_FILE_TAIL_PADDING_TRIGGER;
+  // 测试写一个最大padding entry的场景
+  // 首先写30条2MB的group log
+  EXPECT_EQ(OB_SUCCESS, submit_log(leader, 30, leader_idx, (2 * 1024 * 1024 - group_entry_header_total_size)));
+  // 接着写文件尾最后一条有效的group entry, 确保文件剩余空间触发生成最大的padding entry
+  EXPECT_EQ(OB_SUCCESS, submit_log(leader, 1, leader_idx, (4 * 1024 * 1024 - MAX_INFO_BLOCK_SIZE - max_valid_group_entry_size - CLOG_FILE_TAIL_PADDING_TRIGGER - group_entry_header_total_size + 1)));
+  // 提交一个2MB+16KB size的log buf, 触发生成padding
+  EXPECT_EQ(OB_SUCCESS, submit_log(leader, 1, leader_idx, MAX_LOG_BODY_SIZE));
+  // 预期max_lsn为单个block文件size+最大valid group entry size
+  const LSN expected_max_lsn(PALF_BLOCK_SIZE + max_valid_group_entry_size);
+  guard.click("submit_log for max size padding entry finish");
+  CLOG_LOG(INFO, "leader submit log finished", K(expected_max_lsn));
+  while (leader.palf_handle_impl_->get_end_lsn() < expected_max_lsn) {
+    usleep(100 * 1000);
+  }
+  EXPECT_EQ(leader.palf_handle_impl_->get_end_lsn(), expected_max_lsn);
+  guard.click("wait leader end_lsn finish");
+  CLOG_LOG(INFO, "leader wait end_lsn finished", K(expected_max_lsn));
+
+  unblock_net(leader_idx, follower_1_idx);
+  std::vector<PalfHandleImplGuard*> palf_list;
+  EXPECT_EQ(OB_SUCCESS, get_cluster_palf_handle_guard(id, palf_list));
+  PalfHandleImplGuard &follower_2 = *palf_list[follower_2_idx];
+  while (follower_2.palf_handle_impl_->get_end_lsn() < expected_max_lsn) {
+    usleep(100 * 1000);
+  }
+  EXPECT_EQ(follower_2.palf_handle_impl_->get_end_lsn(), expected_max_lsn);
+  guard.click("wait follower_2 end_lsn finish");
+  CLOG_LOG(INFO, "follower_2 wait end_lsn finished", K(expected_max_lsn));
+
+  PalfHandleImplGuard &follower_1 = *palf_list[follower_1_idx];
+  // follower_1依赖fetch log追日志，但end_lsn无法推到与leader一致
+  // 因为这里committed_end_lsn依赖周期性的keepAlive日志推进
+  while (follower_1.palf_handle_impl_->get_max_lsn() < expected_max_lsn) {
+    usleep(100 * 1000);
+  }
+  guard.click("wait follower_1 max_lsn finish");
+  CLOG_LOG(INFO, "follower_1 wait max_lsn finished", K(expected_max_lsn));
+
+  EXPECT_EQ(OB_SUCCESS, revert_cluster_palf_handle_guard(palf_list));
+  guard.click("delete");
+  PALF_LOG(INFO, "end test submit_log", K(id), K(guard));
+}
+
 TEST_F(TestObSimpleLogClusterBasicFunc, restart_and_clear_tmp_files)
 {
   SET_CASE_LOG_FILE(TEST_NAME, "restart_and_clear_tmp_files");
diff --git a/src/logservice/palf/log_ack_info.h b/src/logservice/palf/log_ack_info.h
index a00d20d086..475236198b 100644
--- a/src/logservice/palf/log_ack_info.h
+++ b/src/logservice/palf/log_ack_info.h
@@ -25,10 +25,12 @@ struct LsnTsInfo
 {
   LSN lsn_;
   int64_t last_ack_time_us_;
-  LsnTsInfo() : lsn_(), last_ack_time_us_(OB_INVALID_TIMESTAMP)
+  int64_t last_advance_time_us_;
+  LsnTsInfo()
+    : lsn_(), last_ack_time_us_(OB_INVALID_TIMESTAMP), last_advance_time_us_(OB_INVALID_TIMESTAMP)
   {}
   LsnTsInfo(const LSN &lsn, const int64_t ack_time_us)
-    : lsn_(lsn), last_ack_time_us_(ack_time_us)
+    : lsn_(lsn), last_ack_time_us_(ack_time_us), last_advance_time_us_(ack_time_us)
   {}
   bool is_valid() const {
     return (lsn_.is_valid() && OB_INVALID_TIMESTAMP != last_ack_time_us_);
@@ -37,13 +39,15 @@ struct LsnTsInfo
   {
     lsn_.reset();
     last_ack_time_us_ = OB_INVALID_TIMESTAMP;
+    last_advance_time_us_ = OB_INVALID_TIMESTAMP;
   }
   void operator=(const LsnTsInfo &val)
   {
     lsn_ = val.lsn_;
     last_ack_time_us_ = val.last_ack_time_us_;
+    last_advance_time_us_ = val.last_advance_time_us_;
   }
-  TO_STRING_KV(K_(lsn), K_(last_ack_time_us));
+  TO_STRING_KV(K_(lsn), K_(last_ack_time_us), K_(last_advance_time_us));
 };
 
 struct LogMemberAckInfo
diff --git a/src/logservice/palf/log_define.h b/src/logservice/palf/log_define.h
index 8fa30fa8a4..3935cbe196 100644
--- a/src/logservice/palf/log_define.h
+++ b/src/logservice/palf/log_define.h
@@ -60,7 +60,13 @@ const int64_t PALF_PHY_BLOCK_SIZE = 1 << 26;
 const int64_t PALF_BLOCK_SIZE = PALF_PHY_BLOCK_SIZE - MAX_INFO_BLOCK_SIZE;          // log block size is 64M-MAX_INFO_BLOCK_SIZE by default.
 const int64_t PALF_META_BLOCK_SIZE = PALF_PHY_BLOCK_SIZE - MAX_INFO_BLOCK_SIZE;     // meta block size is 64M-MAX_INFO_BLOCK_SIZE by default.
 
-constexpr offset_t MAX_LOG_BUFFER_SIZE = MAX_LOG_BODY_SIZE + MAX_LOG_HEADER_SIZE;
+constexpr int64_t CLOG_FILE_TAIL_PADDING_TRIGGER = 4096;     // 文件尾剩余空间补padding阈值
+// The valid group_entry (not padding entry) size range is:
+//    (0, (MAX_LOG_BODY_SIZE + MAX_LOG_HEADER_SIZE) ).
+// The padding group_entry size range is:
+//    [4KB, (max_valid_group_entry_size + CLOG_FILE_TAIL_PADDING_TRIGGER) ).
+// So the MAX_LOG_BUFFER_SIZE is defined as below:
+constexpr offset_t MAX_LOG_BUFFER_SIZE = MAX_LOG_BODY_SIZE + MAX_LOG_HEADER_SIZE + CLOG_FILE_TAIL_PADDING_TRIGGER;
 
 constexpr offset_t LOG_DIO_ALIGN_SIZE = 4 * 1024;
 constexpr offset_t LOG_DIO_ALIGNED_BUF_SIZE_REDO = MAX_LOG_BUFFER_SIZE + LOG_DIO_ALIGN_SIZE;
@@ -78,6 +84,8 @@ const int64_t MAX_ALLOWED_SKEW_FOR_REF_US = 3600L * 1000 * 1000;          // 1h
 // follower's group buffer size is 8MB larger than leader's.
 const int64_t FOLLOWER_DEFAULT_GROUP_BUFFER_SIZE = LEADER_DEFAULT_GROUP_BUFFER_SIZE + 8 * 1024 * 1024L;
 const int64_t PALF_STAT_PRINT_INTERVAL_US = 1 * 1000 * 1000L;
+// The advance delay threshold for match lsn is 1s.
+const int64_t MATCH_LSN_ADVANCE_DELAY_THRESHOLD_US = 1 * 1000 * 1000L;
 const int64_t PALF_RECONFIRM_FETCH_MAX_LSN_INTERVAL = 1 * 1000 * 1000;
 const int64_t PALF_FETCH_LOG_INTERVAL_US = 2 * 1000 * 1000L;                 // 2s
 const int64_t PALF_FETCH_LOG_RENEW_LEADER_INTERVAL_US = 5 * 1000 * 1000;            // 5s
diff --git a/src/logservice/palf/log_sliding_window.cpp b/src/logservice/palf/log_sliding_window.cpp
index 5a8f827af4..9c9cce32e6 100644
--- a/src/logservice/palf/log_sliding_window.cpp
+++ b/src/logservice/palf/log_sliding_window.cpp
@@ -41,6 +41,12 @@ bool UpdateMatchLsnFunc::operator()(const common::ObAddr &server, LsnTsInfo &val
   if (!value.is_valid()) {
     bool_ret = false;
   } else if (value.lsn_ <= new_end_lsn_) {
+    old_end_lsn_ = value.lsn_;
+    old_advance_time_us_ = value.last_advance_time_us_;
+    if (value.lsn_ < new_end_lsn_) {
+      // Update last_advance_time_us_ when lsn really changes.
+      value.last_advance_time_us_ = new_ack_time_us_;
+    }
     value.lsn_ = new_end_lsn_;
     value.last_ack_time_us_ = new_ack_time_us_;
     bool_ret = true;
@@ -452,7 +458,7 @@ int LogSlidingWindow::submit_log(const char *buf,
       } else if (is_need_handle && FALSE_IT(is_need_handle_next |= is_need_handle)) {
       } else {
         PALF_LOG(INFO, "generate_new_group_log_ for padding log success", K_(palf_id), K_(self), K(log_id),
-            K(tmp_lsn), K(scn), K(is_need_handle), K(is_need_handle_next));
+            K(padding_size), K(tmp_lsn), K(scn), K(is_need_handle), K(is_need_handle_next));
         // after gen padding_entry, update lsn to next block
         tmp_lsn.val_ += padding_size;
         log_id++;  // inc log_id for following new log
@@ -3762,7 +3768,11 @@ int LogSlidingWindow::try_update_match_lsn_map_(const common::ObAddr &server, co
       PALF_LOG(WARN, "match_lsn_map_.operate() failed", K(ret), K_(palf_id), K_(self),
           K(server), K(end_lsn), "curr val", tmp_val);
     } else {
-      // do nothing
+      // Update successfully, check if it advances delay too long.
+      if (update_func.is_advance_delay_too_long()) {
+        PALF_LOG(WARN, "[MATCH LSN ADVANCE DELAY]match_lsn advance delay too much time",
+            K(ret), K_(palf_id), K_(self), K(server), K(update_func));
+      }
     }
   }
   PALF_LOG(TRACE, "try_update_match_lsn_map_ finished", K(ret), K_(palf_id), K_(self), K(server), K(end_lsn));
diff --git a/src/logservice/palf/log_sliding_window.h b/src/logservice/palf/log_sliding_window.h
index 5e81ed3c31..54a7412f61 100644
--- a/src/logservice/palf/log_sliding_window.h
+++ b/src/logservice/palf/log_sliding_window.h
@@ -105,14 +105,26 @@ class UpdateMatchLsnFunc
 {
 public:
   UpdateMatchLsnFunc(const LSN &end_lsn, const int64_t new_ack_time_us)
-      : new_end_lsn_(end_lsn), new_ack_time_us_(new_ack_time_us)
+      : new_end_lsn_(end_lsn), old_end_lsn_(), new_ack_time_us_(new_ack_time_us), old_advance_time_us_(OB_INVALID_TIMESTAMP)
   {}
   ~UpdateMatchLsnFunc() {}
   bool operator()(const common::ObAddr &server, LsnTsInfo &value);
-  TO_STRING_KV(K_(new_end_lsn), K_(new_ack_time_us));
+  bool is_advance_delay_too_long() const {
+    bool bool_ret = false;
+    if (old_end_lsn_ < new_end_lsn_
+        && (new_ack_time_us_ - old_advance_time_us_) > MATCH_LSN_ADVANCE_DELAY_THRESHOLD_US) {
+      // Return true when advance delay exceeds 1s.
+      bool_ret = true;
+    }
+    return bool_ret;
+  }
+  TO_STRING_KV(K_(old_end_lsn), K_(new_end_lsn), K_(old_advance_time_us), K_(new_ack_time_us),
+      "advance delay(us)", new_ack_time_us_ - old_advance_time_us_);
 private:
   LSN new_end_lsn_;
+  LSN old_end_lsn_;
   int64_t new_ack_time_us_;
+  int64_t old_advance_time_us_;
 };
 
 class GetLaggedListFunc
diff --git a/src/logservice/palf/lsn_allocator.h b/src/logservice/palf/lsn_allocator.h
index e5952d3e0b..e3400def82 100644
--- a/src/logservice/palf/lsn_allocator.h
+++ b/src/logservice/palf/lsn_allocator.h
@@ -79,7 +79,6 @@ private:
   static const int64_t LOG_TS_DELTA_UPPER_BOUND = (1ul << LOG_TS_DELTA_BIT_CNT) - 1000;
   static const uint64_t LOG_CUT_TRIGGER = 1 << 21;          // 聚合日志跨2M边界时切分
   static const uint64_t LOG_CUT_TRIGGER_MASK = (1 << 21) - 1;
-  static const int64_t CLOG_FILE_TAIL_PADDING_TRIGGER = 4096;     // 文件尾剩余空间补padding阈值
   static const uint64_t MAX_SUPPORTED_BLOCK_ID = 0xfffffffff - 1000;  // block_id告警阈值
   static const uint64_t MAX_SUPPORTED_BLOCK_OFFSET = 0xfffffff;        // block_offset的最大支持256MB
 private:
diff --git a/src/logservice/palf/palf_handle_impl.cpp b/src/logservice/palf/palf_handle_impl.cpp
index 08910769b7..3be3c9da36 100644
--- a/src/logservice/palf/palf_handle_impl.cpp
+++ b/src/logservice/palf/palf_handle_impl.cpp
@@ -2837,6 +2837,8 @@ int PalfHandleImpl::try_send_committed_info_(const ObAddr &server,
   AccessMode access_mode;
   if (!log_lsn.is_valid() || !log_end_lsn.is_valid() || INVALID_PROPOSAL_ID == log_proposal_id) {
     ret = OB_INVALID_ARGUMENT;
+    PALF_LOG(WARN, "invalid arguments", K(ret), KPC(this), K(server), K(log_lsn), K(log_end_lsn),
+        K(log_proposal_id));
   } else if (OB_FAIL(mode_mgr_.get_access_mode(access_mode))) {
     PALF_LOG(WARN, "get_access_mode failed", K(ret), KPC(this));
   } else if (AccessMode::APPEND == access_mode) {