demo地址：BulkAll

批量导入

实现目标：想要使用ElasticSearch的 .Net Api客户端NEST批量导入数据，并发异步高效的批量导入
NEST提供了BulkAll
不废话，上代码

            const int size = 1000;
            var tokenSource = new CancellationTokenSource();

            var observableBulk = elasticClient.BulkAll(list, f => f
                    .MaxDegreeOfParallelism(8)
                    .BackOffTime(TimeSpan.FromSeconds(10))
                    .BackOffRetries(2)
                    .Size(size)
                    .RefreshOnCompleted()
                    .Index(indexName)
                    .BufferToBulk((r, buffer) => r.IndexMany(buffer))
                , tokenSource.Token);

            var countdownEvent = new CountdownEvent(1);

            Exception exception = null;

            var bulkAllObserver = new BulkAllObserver();

            observableBulk.Subscribe(bulkAllObserver);

            countdownEvent.Wait(tokenSource.Token);

如果想要对处理导入过程进行监控可以这么替换BulkAllObserver

               var bulkAllObserver = new BulkAllObserver(
                onNext: response =>
                {
                    WriteLine($"Indexed {response.Page * size} with {response.Retries} retries");
                },
                onError: ex =>
                {
                    WriteLine("BulkAll Error : {0}", ex);
                    exception = ex;
                    countdownEvent.Signal();
                },
                () =>
                {
                    WriteLine("BulkAll Finished");
                    countdownEvent.Signal();
                });

还可以使用C#的local function特性，如下所示

            void OnCompleted()
            {
                WriteLine("BulkAll Finished");
                countdownEvent.Signal();
            }

            var bulkAllObserver = new BulkAllObserver(
                onNext: response =>
                {
                    WriteLine($"Indexed {response.Page * size} with {response.Retries} retries");
                },
                onError: ex =>
                {
                    WriteLine("BulkAll Error : {0}", ex);
                    exception = ex;
                    countdownEvent.Signal();
                },
                OnCompleted);

完成demo，请点击 BulkAll 查看