feat(collector): add statistics for estimate key number of partition

src/server/pegasus_server_impl.cpp

@@ -338,6 +338,10 @@ pegasus_server_impl::pegasus_server_impl(dsn::replication::replica *r)
     snprintf(name, 255, "rdb.memtable.memory_usage@%s", str_gpid.c_str());
     _pfc_rdb_memtable_mem_usage.init_app_counter(
         "app.pegasus", name, COUNTER_TYPE_NUMBER, "statistic the memory usage of rocksdb memtable");
+
+    snprintf(name, 255, "rdb.estimate.key_number@%s", str_gpid.c_str());
+    _pfc_rdb_estimate_key_number.init_app_counter(
+        "app.pegasus", name, COUNTER_TYPE_NUMBER, "statistic the key number of rocksdb all data");
 }
 
 void pegasus_server_impl::parse_checkpoints()
@@ -2242,6 +2246,12 @@ void pegasus_server_impl::update_replica_rocksdb_statistics()
         _pfc_rdb_memtable_mem_usage->set(val);
         dinfo_replica("_pfc_rdb_memtable_mem_usage: {} bytes", val);
     }
+
+    if (_db->GetProperty(rocksdb::DB::Properties::kEstimateNumKeys, &str_val) &&
+        dsn::buf2uint64(str_val, val)) {
+        _pfc_rdb_estimate_key_number->set(val);
+        dinfo_replica("_pfc_rdb_estimate_key_number: {}", val);
+    }
 }
 
 void pegasus_server_impl::update_server_rocksdb_statistics()

src/server/pegasus_server_impl.h

@@ -364,6 +364,7 @@ class pegasus_server_impl : public ::dsn::apps::rrdb_service
     ::dsn::perf_counter_wrapper _pfc_rdb_block_cache_total_count;
     ::dsn::perf_counter_wrapper _pfc_rdb_index_and_filter_blocks_mem_usage;
     ::dsn::perf_counter_wrapper _pfc_rdb_memtable_mem_usage;
+    ::dsn::perf_counter_wrapper _pfc_rdb_estimate_key_number;
 };
 
 } // namespace server

src/server/test/pegasus_server_impl_test.cpp

@@ -3,15 +3,26 @@
 // can be found in the LICENSE file in the root directory of this source tree.
 
 #include <base/pegasus_key_schema.h>
+#include <dsn/utility/defer.h>
+#include "server/pegasus_server_write.h"
+#include "server/pegasus_write_service_impl.h"
 #include "pegasus_server_test_base.h"
+#include "message_utils.h"
 
 namespace pegasus {
 namespace server {
 
 class pegasus_server_impl_test : public pegasus_server_test_base
 {
+
+    std::unique_ptr<pegasus_server_write> _server_write;
+
 public:
-    pegasus_server_impl_test() : pegasus_server_test_base() { start(); }
+    pegasus_server_impl_test() : pegasus_server_test_base()
+    {
+        start();
+        _server_write = dsn::make_unique<pegasus_server_write>(_server.get(), true);
+    }
 
     void test_table_level_slow_query()
     {
@@ -55,9 +66,33 @@ class pegasus_server_impl_test : public pegasus_server_test_base
             ASSERT_EQ(before_count + test.expect_perf_counter_incr, after_count);
         }
     }
+
+    void test_table_property()
+    {
+        std::unique_ptr<pegasus_server_write> _server_write;
+        _server_write = dsn::make_unique<pegasus_server_write>(_server.get(), true);
+        dsn::blob key;
+        pegasus_generate_key(key, std::string("hash"), std::string("sort"));
+        dsn::apps::update_request req;
+        req.key = key;
+        req.value.assign("value", 0, 5);
+
+        int put_rpc_cnt = 5;
+        auto writes = new dsn::message_ex *[put_rpc_cnt];
+        for (int i = 0; i < put_rpc_cnt; i++) {
+            writes[i] = pegasus::create_put_request(req);
+        }
+        _server_write->on_batched_write_requests(writes, put_rpc_cnt, 0, 0);
+
+        std::string str_val;
+        _server->_db->GetProperty(rocksdb::DB::Properties::kEstimateNumKeys, &str_val);
+        ASSERT_EQ(str_val, std::to_string(put_rpc_cnt));
+    }
 };
 
 TEST_F(pegasus_server_impl_test, test_table_level_slow_query) { test_table_level_slow_query(); }
 
+TEST_F(pegasus_server_impl_test, test_table_property) { test_table_property(); }
+
 } // namespace server
 } // namespace pegasus