diff --git a/deps/oblib/src/lib/ob_define.h b/deps/oblib/src/lib/ob_define.h
index c27739902..4ac9e4d0a 100644
--- a/deps/oblib/src/lib/ob_define.h
+++ b/deps/oblib/src/lib/ob_define.h
@@ -791,7 +791,8 @@ const int64_t OB_MAX_DDL_SINGLE_REPLICA_BUILD_TIMEOUT = 7L * 24L * 60L * 60L * 1
 const char *const OB_STANDBY_USER_NAME = "__oceanbase_inner_standby_user";
 
 const double TENANT_RESERVE_MEM_RATIO = 0.1;
-const int64_t LEAST_MEMORY_SIZE = 2L << 30;
+const int64_t LEAST_MEMORY_SIZE = 1L << 30;
+const int64_t LEAST_MEMORY_SIZE_FOR_NORMAL_MODE = 2L << 30;
 const int64_t SYS_MAX_ALLOCATE_MEMORY = 1L << 34;
 
 // mem factor
diff --git a/deps/oblib/src/lib/ob_running_mode.cpp b/deps/oblib/src/lib/ob_running_mode.cpp
index 0b186ee95..450ffc695 100644
--- a/deps/oblib/src/lib/ob_running_mode.cpp
+++ b/deps/oblib/src/lib/ob_running_mode.cpp
@@ -15,6 +15,7 @@
 
 namespace oceanbase {
 namespace lib {
+const int64_t ObRunningModeConfig::MIN_MEM = 1L << 30;  // The minimum value for memory_limit.
 const int64_t ObRunningModeConfig::MINI_MEM_LOWER = 4L << 30;
 const int64_t ObRunningModeConfig::MINI_MEM_UPPER = 12L << 30;
 } //end of namespace lib
diff --git a/deps/oblib/src/lib/ob_running_mode.h b/deps/oblib/src/lib/ob_running_mode.h
index b19a4b8ba..169a4633e 100644
--- a/deps/oblib/src/lib/ob_running_mode.h
+++ b/deps/oblib/src/lib/ob_running_mode.h
@@ -20,6 +20,7 @@ namespace lib
 {
 struct ObRunningModeConfig
 {
+  static const int64_t MIN_MEM;
   static const int64_t MINI_MEM_LOWER;
   static const int64_t MINI_MEM_UPPER;
   bool mini_mode_ = false;
diff --git a/src/observer/ob_server.cpp b/src/observer/ob_server.cpp
index 2cdf07f58..2e7817fca 100644
--- a/src/observer/ob_server.cpp
+++ b/src/observer/ob_server.cpp
@@ -1624,11 +1624,11 @@ int ObServer::init_pre_setting()
     const int64_t reserved_memory = std::min(config_.cache_wash_threshold.get_value(),
         static_cast<int64_t>(static_cast<double>(limit_memory) * KVCACHE_FACTOR));
     const int64_t reserved_urgent_memory = config_.memory_reserved;
-    if (!is_arbitration_mode()
-        && LEAST_MEMORY_SIZE >= limit_memory) {
+    const int64_t need_memory_size = is_arbitration_mode() ? LEAST_MEMORY_SIZE : LEAST_MEMORY_SIZE_FOR_NORMAL_MODE;
+    if (need_memory_size > limit_memory) {
       ret = OB_INVALID_CONFIG;
       LOG_ERROR("memory limit for oceanbase isn't sufficient",
-                "need", LEAST_MEMORY_SIZE,
+                K(need_memory_size),
                 "limit to", limit_memory,
                 "sys mem", get_phy_mem_size(),
                 K(reserved_memory),
diff --git a/src/observer/ob_server.h b/src/observer/ob_server.h
index edd6c90aa..92786b0b8 100644
--- a/src/observer/ob_server.h
+++ b/src/observer/ob_server.h
@@ -239,6 +239,7 @@ public:
   sql::ObConnectResourceMgr& get_conn_res_mgr() { return conn_res_mgr_; }
   obrpc::ObTableRpcProxy &get_table_rpc_proxy() { return table_rpc_proxy_; }
   share::ObLocationService &get_location_service() { return location_service_; }
+  bool is_arbitration_mode() const;
 private:
   int stop();
 
@@ -300,7 +301,6 @@ private:
   int parse_mode();
 
   // ------------------------------- arb server start ------------------------------------
-  bool is_arbitration_mode() const;
   int start_sig_worker_and_handle();
   int init_server_in_arb_mode();
   int start_server_in_arb_mode();
diff --git a/src/observer/ob_server_reload_config.cpp b/src/observer/ob_server_reload_config.cpp
index b01faa2fc..b63ee89d5 100644
--- a/src/observer/ob_server_reload_config.cpp
+++ b/src/observer/ob_server_reload_config.cpp
@@ -52,6 +52,7 @@ int set_cluster_name_hash(const ObString &cluster_name)
     LOG_WARN("failed to calc_cluster_name_hash", KR(ret), K(cluster_name));
   } else {
     obrpc::ObRpcNetHandler::CLUSTER_NAME_HASH = cluster_name_hash;
+    LOG_INFO("set cluster_name_hash", KR(ret), K(cluster_name), K(cluster_name_hash));
   }
   return ret;
 }
@@ -88,6 +89,7 @@ int ObServerReloadConfig::operator()()
 {
   int ret = OB_SUCCESS;
   int real_ret = ret;
+  const bool is_arbitration_mode = OBSERVER.is_arbitration_mode();
 
   if (!gctx_.is_inited()) {
     real_ret = ret = OB_INNER_STAT_ERROR;
@@ -155,27 +157,30 @@ int ObServerReloadConfig::operator()()
     ObMallocSampleLimiter::set_interval(GCONF._max_malloc_sample_interval,
                                      GCONF._min_malloc_sample_interval);
 #endif
-    ObIOConfig io_config;
-    int64_t cpu_cnt = GCONF.cpu_count;
-    if (cpu_cnt <= 0) {
-      cpu_cnt = common::get_cpu_num();
-    }
-    io_config.disk_io_thread_count_ = GCONF.disk_io_thread_count;
-    // In the 2.x version, reuse the sys_bkgd_io_timeout configuration item to indicate the data disk io timeout time
-    // After version 3.1, use the data_storage_io_timeout configuration item.
-    io_config.data_storage_io_timeout_ms_ = GCONF._data_storage_io_timeout / 1000L;
-    io_config.data_storage_warning_tolerance_time_ = GCONF.data_storage_warning_tolerance_time;
-    io_config.data_storage_error_tolerance_time_ = GCONF.data_storage_error_tolerance_time;
-    if (OB_FAIL(ObIOManager::get_instance().set_io_config(io_config))) {
-      real_ret = ret;
-      LOG_WARN("reload io manager config fail, ", K(ret));
-    }
+    if (!is_arbitration_mode) {
+      ObIOConfig io_config;
+      int64_t cpu_cnt = GCONF.cpu_count;
+      if (cpu_cnt <= 0) {
+        cpu_cnt = common::get_cpu_num();
+      }
+      io_config.disk_io_thread_count_ = GCONF.disk_io_thread_count;
+      // In the 2.x version, reuse the sys_bkgd_io_timeout configuration item to indicate the data disk io timeout time
+      // After version 3.1, use the data_storage_io_timeout configuration item.
+      io_config.data_storage_io_timeout_ms_ = GCONF._data_storage_io_timeout / 1000L;
+      io_config.data_storage_warning_tolerance_time_ = GCONF.data_storage_warning_tolerance_time;
+      io_config.data_storage_error_tolerance_time_ = GCONF.data_storage_error_tolerance_time;
+      if (!is_arbitration_mode
+          && OB_FAIL(ObIOManager::get_instance().set_io_config(io_config))) {
+        real_ret = ret;
+        LOG_WARN("reload io manager config fail, ", K(ret));
+      }
 
-    (void)reload_diagnose_info_config(GCONF.enable_perf_event);
-    (void)reload_trace_log_config(GCONF.enable_record_trace_log);
+      (void)reload_diagnose_info_config(GCONF.enable_perf_event);
+      (void)reload_trace_log_config(GCONF.enable_record_trace_log);
 
-    reload_tenant_freezer_config_();
-    reload_tenant_scheduler_config_();
+      reload_tenant_freezer_config_();
+      reload_tenant_scheduler_config_();
+    }
   }
   {
     ObMallocAllocator *malloc_allocator = ObMallocAllocator::get_instance();
@@ -190,14 +195,18 @@ int ObServerReloadConfig::operator()()
   const int64_t cache_size = GCONF.memory_chunk_cache_size;
   const int cache_cnt = (cache_size > 0 ? cache_size : GMEMCONF.get_server_memory_limit()) / INTACT_ACHUNK_SIZE;
   lib::AChunkMgr::instance().set_max_chunk_cache_cnt(cache_cnt);
-  if (GCONF.cluster_id.get_value() >= 0) {
-    obrpc::ObRpcNetHandler::CLUSTER_ID = GCONF.cluster_id.get_value();
-    LOG_INFO("set CLUSTER_ID for rpc", "cluster_id", GCONF.cluster_id.get_value());
-  }
 
-  if (FAILEDx(set_cluster_name_hash(GCONF.cluster.str()))) {
-    LOG_WARN("failed to set_cluster_name_hash", KR(ret), "cluster_name", GCONF.cluster.str(),
-                                              "cluster_name_len", strlen(GCONF.cluster.str()));
+  if (!is_arbitration_mode) {
+    // Refresh cluster_id, cluster_name_hash for non arbitration mode
+    if (GCONF.cluster_id.get_value() > 0) {
+      obrpc::ObRpcNetHandler::CLUSTER_ID = GCONF.cluster_id.get_value();
+      LOG_INFO("set CLUSTER_ID for rpc", "cluster_id", GCONF.cluster_id.get_value());
+    }
+
+    if (FAILEDx(set_cluster_name_hash(GCONF.cluster.str()))) {
+      LOG_WARN("failed to set_cluster_name_hash", KR(ret), "cluster_name", GCONF.cluster.str(),
+                                                "cluster_name_len", strlen(GCONF.cluster.str()));
+    }
   }
 
   // reset mem leak
@@ -250,7 +259,7 @@ int ObServerReloadConfig::operator()()
     obrpc::set_rpc_checksum_check_level(new_level);
   }
 
-  {
+  if (!is_arbitration_mode) {
     auto new_upgrade_stage = obrpc::get_upgrade_stage(GCONF._upgrade_stage.str());
     auto orig_upgrade_stage = GCTX.get_upgrade_stage();
     if (new_upgrade_stage != orig_upgrade_stage) {
@@ -267,8 +276,8 @@ int ObServerReloadConfig::operator()()
 
   lib::g_runtime_enabled = true;
 
-  common::ObKVGlobalCache::get_instance().reload_wash_interval();
-  {
+  if (!is_arbitration_mode) {
+    common::ObKVGlobalCache::get_instance().reload_wash_interval();
     int tmp_ret = OB_SUCCESS;
     int64_t data_disk_size = 0;
     int64_t data_disk_percentage = 0;
diff --git a/src/share/config/ob_config_helper.cpp b/src/share/config/ob_config_helper.cpp
index ac1d9d0be..8d768b0eb 100644
--- a/src/share/config/ob_config_helper.cpp
+++ b/src/share/config/ob_config_helper.cpp
@@ -345,7 +345,7 @@ bool ObConfigMemoryLimitChecker::check(const ObConfigItem &t) const
   bool is_valid = false;
   int64_t value = ObConfigCapacityParser::get(t.str(), is_valid);
   if (is_valid) {
-    is_valid = 0 == value || value >= lib::ObRunningModeConfig::instance().MINI_MEM_LOWER;
+    is_valid = 0 == value || value >= lib::ObRunningModeConfig::instance().MIN_MEM;
   }
   return is_valid;
 }
diff --git a/src/share/config/ob_server_config.cpp b/src/share/config/ob_server_config.cpp
index f6845af69..d3aa73d10 100644
--- a/src/share/config/ob_server_config.cpp
+++ b/src/share/config/ob_server_config.cpp
@@ -21,6 +21,7 @@
 #include "lib/net/ob_net_util.h"
 #include "common/ob_record_header.h"
 #include "common/ob_zone.h"
+#include "observer/ob_server.h"
 #include "share/ob_dml_sql_splicer.h"
 #include "share/inner_table/ob_inner_table_schema.h"
 #include "share/unit/ob_unit_resource.h"     // ObUnitResource
@@ -215,15 +216,26 @@ ObServerMemoryConfig &ObServerMemoryConfig::get_instance()
 int ObServerMemoryConfig::reload_config(const ObServerConfig& server_config)
 {
   int ret = OB_SUCCESS;
+  const bool is_arbitration_mode = OBSERVER.is_arbitration_mode();
   int64_t memory_limit = server_config.memory_limit;
   if (0 == memory_limit) {
     memory_limit = get_phy_mem_size() * server_config.memory_limit_percentage / 100;
   }
   int64_t system_memory = server_config.system_memory;
+  bool is_valid_config = true;
   if (0 == system_memory) {
     int64_t memory_limit_g = memory_limit >> 30;
-    if (memory_limit_g < 4) {
-      LOG_ERROR("memory_limit with unexpected value", K(memory_limit));
+    if (memory_limit_g < 1) {
+      // memory_limit should not be less than 1G for arbitration mode
+      is_valid_config = false;
+      LOG_ERROR("memory_limit with unexpected value", K(ret), K(memory_limit), "phy mem", get_phy_mem_size());
+    } else if (is_arbitration_mode) {
+      // keep system_memory = 0 for arbitration mode
+    } else if (memory_limit_g < 4) {
+      // memory_limit should not be less than 4G for non arbitration mode
+      is_valid_config = false;
+      LOG_ERROR("memory_limit with unexpected value", K(ret), K(memory_limit), "phy mem", get_phy_mem_size());
+      LOG_ERROR("memory_limit with unexpected value", K(ret), K(memory_limit), "phy mem", get_phy_mem_size());
     } else if (memory_limit_g <= 8) {
       system_memory = 2LL << 30;
     } else if (memory_limit_g <= 16) {
@@ -238,7 +250,8 @@ int ObServerMemoryConfig::reload_config(const ObServerConfig& server_config)
       system_memory = int64_t(15 + 3 * (sqrt(memory_limit_g) - 8)) << 30;
     }
   }
-  if (memory_limit > system_memory) {
+  if (!is_valid_config) {
+  } else if (memory_limit > system_memory) {
     memory_limit_ = memory_limit;
     system_memory_ = system_memory;
     LOG_INFO("update memory_limit or system_memory success",
diff --git a/src/share/parameter/ob_parameter_seed.ipp b/src/share/parameter/ob_parameter_seed.ipp
index f49b92eb4..bf029dbe7 100644
--- a/src/share/parameter/ob_parameter_seed.ipp
+++ b/src/share/parameter/ob_parameter_seed.ipp
@@ -77,7 +77,7 @@ DEF_INT(tenant_task_queue_size, OB_CLUSTER_PARAMETER, "16384", "[1024,]",
         ObParameterAttr(Section::OBSERVER, Source::DEFAULT, EditLevel::DYNAMIC_EFFECTIVE));
 _DEF_PARAMETER_SCOPE_CHECKER_EASY(private, Capacity, memory_limit, OB_CLUSTER_PARAMETER, "0",
         common::ObConfigMemoryLimitChecker, "[0M,)",
-        "the size of the memory reserved for internal use(for testing purpose), 0 means follow memory_limit_percentage. Range: 0, [4G,).",
+        "the size of the memory reserved for internal use(for testing purpose), 0 means follow memory_limit_percentage. Range: 0, [1G,).",
         ObParameterAttr(Section::OBSERVER, Source::DEFAULT, EditLevel::DYNAMIC_EFFECTIVE));
 DEF_CAP(rootservice_memory_limit, OB_CLUSTER_PARAMETER, "2G", "[2G,)",
         "max memory size which can be used by rs tenant The default value is 2G. Range: [2G,)",
@@ -976,8 +976,8 @@ DEF_INT(module_test_trx_memory_errsim_percentage, OB_CLUSTER_PARAMETER, "0", "[0
 DEF_CAP(sql_work_area, OB_TENANT_PARAMETER, "1G", "[10M,)",
         "Work area memory limitation for tenant",
         ObParameterAttr(Section::OBSERVER, Source::DEFAULT, EditLevel::STATIC_EFFECTIVE));
-DEF_CAP(__easy_memory_limit, OB_CLUSTER_PARAMETER, "4G", "[1G,)",
-        "max memory size which can be used by libeasy. The default value is 4G. Range: [1G,)",
+DEF_CAP(__easy_memory_limit, OB_CLUSTER_PARAMETER, "4G", "[256M,)",
+        "max memory size which can be used by libeasy. The default value is 4G. Range: [256M,)",
         ObParameterAttr(Section::OBSERVER, Source::DEFAULT, EditLevel::DYNAMIC_EFFECTIVE));
 DEF_CAP(stack_size, OB_CLUSTER_PARAMETER, "512K", "[512K, 20M]",
         "the size of routine execution stack"