feat(rocksdb): Support to open rocksdb with or without meta CF (#549)

src/server/pegasus_server_impl.cpp

@@ -48,6 +48,8 @@ std::shared_ptr<rocksdb::Cache> pegasus_server_impl::_s_block_cache;
 ::dsn::task_ptr pegasus_server_impl::_update_server_rdb_stat;
 ::dsn::perf_counter_wrapper pegasus_server_impl::_pfc_rdb_block_cache_mem_usage;
 const std::string pegasus_server_impl::COMPRESSION_HEADER = "per_level:";
+const std::string pegasus_server_impl::DATA_COLUMN_FAMILY_NAME = "default";
+const std::string pegasus_server_impl::META_COLUMN_FAMILY_NAME = "pegasus_meta_cf";
 
 pegasus_server_impl::pegasus_server_impl(dsn::replication::replica *r)
     : dsn::apps::rrdb_service(r),
@@ -452,8 +454,7 @@ pegasus_server_impl::~pegasus_server_impl()
 {
     if (_is_open) {
         dassert(_db != nullptr, "");
-        delete _db;
-        _db = nullptr;
+        release_db();
     }
 }
 
@@ -1647,6 +1648,7 @@ ::dsn::error_code pegasus_server_impl::start(int argc, char **argv)
     //          2, we can parse restore info from app env, which is stored in argv
     //          3, restore_dir is exist
     //
+    bool db_exist = true;
     auto path = ::dsn::utils::filesystem::path_combine(data_dir(), "rdb");
     if (::dsn::utils::filesystem::path_exists(path)) {
         // only case 1
@@ -1662,6 +1664,7 @@ ::dsn::error_code pegasus_server_impl::start(int argc, char **argv)
                        replica_name());
                 return ::dsn::ERR_FILE_OPERATION_FAILED;
             } else {
+                db_exist = false;
                 dinfo("%s: open a new db, path = %s", replica_name(), path.c_str());
             }
         } else {
@@ -1688,6 +1691,7 @@ ::dsn::error_code pegasus_server_impl::start(int argc, char **argv)
                            restore_dir.c_str());
                     return ::dsn::ERR_FILE_OPERATION_FAILED;
                 } else {
+                    db_exist = false;
                     dwarn(
                         "%s: try to restore and restore_dir(%s) isn't exist, but we don't force "
                         "it, the role of this replica must not primary, so we open a new db on the "
@@ -1702,16 +1706,36 @@ ::dsn::error_code pegasus_server_impl::start(int argc, char **argv)
 
     ddebug("%s: start to open rocksDB's rdb(%s)", replica_name(), path.c_str());
 
-    auto status = rocksdb::DB::Open(rocksdb::Options(_db_opts, _data_cf_opts), path, &_db);
+    bool need_open_with_meta_cf = false;
+    // Check meta CF only when db exist.
+    if (db_exist && check_meta_cf(path, &need_open_with_meta_cf) != ::dsn::ERR_OK) {
+        derror_replica("check meta column family failed");
+        return ::dsn::ERR_LOCAL_APP_FAILURE;
+    }
+    std::vector<rocksdb::ColumnFamilyDescriptor> column_families(
+        {{DATA_COLUMN_FAMILY_NAME, _data_cf_opts}});
+    if (need_open_with_meta_cf) {
+        column_families.emplace_back(rocksdb::ColumnFamilyDescriptor(
+            META_COLUMN_FAMILY_NAME, rocksdb::ColumnFamilyOptions()));
+    }
+    std::vector<rocksdb::ColumnFamilyHandle *> handles_opened;
+    auto status = rocksdb::DB::Open(_db_opts, path, column_families, &handles_opened, &_db);
     if (status.ok()) {
+        dcheck_eq_replica(column_families.size(), handles_opened.size());
+        dcheck_eq_replica(handles_opened[0]->GetName(), DATA_COLUMN_FAMILY_NAME);
+        _data_cf = handles_opened[0];
+        if (handles_opened.size() == 2) {
+            dcheck_eq_replica(handles_opened[1]->GetName(), META_COLUMN_FAMILY_NAME);
+            _meta_cf = handles_opened[1];
+        }
+
         _last_committed_decree = _db->GetLastFlushedDecree();
         _pegasus_data_version = _db->GetPegasusDataVersion();
         if (_pegasus_data_version > PEGASUS_DATA_VERSION_MAX) {
             derror("%s: open app failed, unsupported data version %" PRIu32,
                    replica_name(),
                    _pegasus_data_version);
-            delete _db;
-            _db = nullptr;
+            release_db();
             return ::dsn::ERR_LOCAL_APP_FAILURE;
         }
 
@@ -1736,8 +1760,7 @@ ::dsn::error_code pegasus_server_impl::start(int argc, char **argv)
             auto err = async_checkpoint(false);
             if (err != ::dsn::ERR_OK) {
                 derror("%s: create checkpoint failed, error = %s", replica_name(), err.to_string());
-                delete _db;
-                _db = nullptr;
+                release_db();
                 return err;
             }
             dassert(last_flushed == last_durable_decree(),
@@ -1822,8 +1845,7 @@ ::dsn::error_code pegasus_server_impl::stop(bool clear_state)
     _context_cache.clear();
 
     _is_open = false;
-    delete _db;
-    _db = nullptr;
+    release_db();
 
     std::deque<int64_t> reserved_checkpoints;
     {
@@ -2894,5 +2916,41 @@ void pegasus_server_impl::set_partition_version(int32_t partition_version)
     // TODO(heyuchen): set filter _partition_version in further pr
 }
 
+::dsn::error_code pegasus_server_impl::check_meta_cf(const std::string &path,
+                                                     bool *need_open_with_meta_cf)
+{
+    *need_open_with_meta_cf = false;
+    std::vector<std::string> column_families;
+    auto s = rocksdb::DB::ListColumnFamilies(rocksdb::DBOptions(), path, &column_families);
+    if (!s.ok()) {
+        derror_replica("rocksdb::DB::ListColumnFamilies failed, error = {}", s.ToString());
+        return ::dsn::ERR_LOCAL_APP_FAILURE;
+    }
+
+    for (const auto &column_family : column_families) {
+        if (column_family == DATA_COLUMN_FAMILY_NAME) {
+            continue;
+        }
+        if (column_family == META_COLUMN_FAMILY_NAME) {
+            *need_open_with_meta_cf = true;
+            continue;
+        }
+        dassert_replica(false, "Column family '{}' should not present");
+    }
+    return ::dsn::ERR_OK;
+}
+
+void pegasus_server_impl::release_db()
+{
+    _db->DestroyColumnFamilyHandle(_data_cf);
+    _data_cf = nullptr;
+    if (_meta_cf != nullptr) {
+        _db->DestroyColumnFamilyHandle(_meta_cf);
+    }
+    _meta_cf = nullptr;
+    delete _db;
+    _db = nullptr;
+}
+
 } // namespace server
 } // namespace pegasus

src/server/pegasus_server_impl.h

@@ -300,8 +300,14 @@ class pegasus_server_impl : public ::dsn::apps::rrdb_service
         return false;
     }
 
+    ::dsn::error_code check_meta_cf(const std::string &path, bool *need_open_with_meta_cf);
+    void release_db();
+
 private:
     static const std::string COMPRESSION_HEADER;
+    // Column family names.
+    static const std::string DATA_COLUMN_FAMILY_NAME;
+    static const std::string META_COLUMN_FAMILY_NAME;
 
     dsn::gpid _gpid;
     std::string _primary_address;
@@ -322,7 +328,9 @@ class pegasus_server_impl : public ::dsn::apps::rrdb_service
     rocksdb::ReadOptions _data_cf_rd_opts;
     std::string _usage_scenario;
 
-    rocksdb::DB *_db;
+    rocksdb::DB *_db = nullptr;
+    rocksdb::ColumnFamilyHandle *_data_cf = nullptr;
+    rocksdb::ColumnFamilyHandle *_meta_cf = nullptr;
     static std::shared_ptr<rocksdb::Cache> _s_block_cache;
     volatile bool _is_open;
     uint32_t _pegasus_data_version;