Rgw Meta临时同步与数据管理

// 同步 run_sync_thread
auto async_processor = svc.rados->get_async_processor();
std::lock_guard l{meta_sync_thread_lock};
meta_sync_processor_thread = new RGWMetaSyncProcessorThread(this->store, async_processor);
ret = meta_sync_processor_thread->init();
meta_sync_processor_thread->start();

// configure the bucket trim manager
rgw::BucketTrimConfig config;
rgw::configure_bucket_trim(cct, config);
bucket_trim.emplace(this->store, config);
ret = bucket_trim->init();
svc.datalog_rados->set_observer(&*bucket_trim);

std::lock_guard dl{data_sync_thread_lock};
for (auto source_zone : svc.zone->get_data_sync_source_zones()) {
  ldout(cct, 5) << "starting data sync thread for zone " << source_zone->name << dendl;
  auto *thread = new RGWDataSyncProcessorThread(this->store, svc.rados->get_async_processor(), source_zone);
  ret = thread->init();
  thread->start();
  data_sync_processor_threads[rgw_zone_id(source_zone->id)] = thread;
}

auto interval = cct->_conf->rgw_sync_log_trim_interval;
if (interval > 0) {
  sync_log_trimmer = new RGWSyncLogTrimThread(this->store, &*bucket_trim, interval);
  ret = sync_log_trimmer->init();
  sync_log_trimmer->start();
}

//构造过程  
RGWMetaSyncProcessorThread(this->store, async_processor);
sync(_store, async_rados) 
master_log(this, store, async_rados, this)

// 初始化  RGWMetaSyncProcessorThread
int RGWMetaSyncStatusManager::init() {
  // ioctx 成员变量，打开log_pool
  int r = rgw_init_ioctx(store->getRados()->get_rados_handle(), store->svc()->zone->get_zone_params().log_pool, ioctx, true);

  // RGWRemoteMetaLog master_log;   master_log(this, store, async_rados, this) this=RGWMetaSyncStatusManager
  r = master_log.init();  // RGWRemoteMetaLog::init

  RGWMetaSyncEnv& sync_env = master_log.get_sync_env();
  rgw_meta_sync_status sync_status;
  // 从 "mdlog.sync-status" 读取同步状态
  // 从 "mdlog.sync-status.shard.<shardId>" 中读取同步marker，既是同步的位置
  r = read_sync_status(&sync_status);
  int num_shards = sync_status.sync_info.num_shards;  // 8
  for (int i = 0; i < num_shards; i++) {
    shard_objs[i] = rgw_raw_obj(store->svc()->zone->get_zone_params().log_pool, sync_env.shard_obj_name(i));
  }
}

// 启动  线程开始执行
RGWRemoteMetaLog::run_sync 
rgw_mdlog_info mdlog_info;
// 获取master_zone的 rgw_md_log_max_shards 以及 period信息， master_zone的处理函数： RGWOp_MDLog_Info::execute