elasticsearch - 阻止只读操作的索引，使Elasticsearch处于不一致状态

Question

如果要对该索引进行重新索引处理，我想阻止索引进行写操作。
这两个帖子(elasticsearch migrations with c and nest和NEST Elasticsearch Reindex examples)都非常有帮助，但是正如this third one所建议的那样，您可能会在此过程的中间丢失更新和删除内容。
我尝试使用elasticsearch中的设置阻止索引进行写操作，但尝试此操作时发现了一些问题。
我使用Nest的UpdateSettings api来更改设置blocks.read_only，blocks.metadata，blocks.read和blocks.write:

var client = CreateElasticClient(); // A wrapper method of ElasticClient()
var response = client.UpdateSettings(r => r
                    .Index(IndexName)
                    .BlockReadonly()
                    .BlocksMetadata()
                    .BlocksRead()
                    .BlocksWrite()
                    );

如果我将设置 blocks.read_only， blocks.metadata和 blocks.read设置为true(默认设置为值)，那么索引将不接受写入操作，但也不允许读取操作，确切地说，我不得不在三种情况下重新安装elasticsearch今天，因为更改这些设置后我什么也做不了。
将 blocks.write设置为true不会有任何效果，我可以读取索引，但也可以编写索引。
问题
所以，我的问题是，我应该怎么做(在对索引进行重新索引时阻止索引进行写操作)？

Answer 1

我准备了一个简单的例子。也许它将为您的问题锦上添花。

internal class Program
{
    private static void Main(string[] args)
    {
        var indexName = "indexname";
        var indexName2 = "indexname2";

        var uri = new Uri("http://localhost:9200");
        var settings = new ConnectionSettings(uri).SetDefaultIndex(indexName).EnableTrace();
        var client = new ElasticClient(settings);

        var indicesResponse = client.DeleteIndex(descriptor => descriptor.Index(indexName));
        var indicesResponse2 = client.DeleteIndex(descriptor => descriptor.Index(indexName2));

        client.CreateIndex(descriptor => descriptor.Index(indexName).AddMapping<Document>(m => m.MapFromAttributes()));

        client.Index(new Document {Id = 1});

        client.Refresh();

        var acknowledgedResponse = client.UpdateSettings(descriptor => descriptor.Index(indexName).BlocksWrite());

        var observable = client.Reindex<Document>(descriptor => descriptor.FromIndex(indexName).ToIndex(indexName2));
        observable.Subscribe(new ReindexObserver<Document>(response => Console.WriteLine(response.IsValid),
            Console.WriteLine, () => Console.WriteLine("Done")));

        var documentToAdd = new Document { Id = 2, Name = "new" };

        var indexResponse = client.Index(documentToAdd);

        //indexResponse -> can't index new document with message: blocked by: [FORBIDDEN/8/index write (api)];

        var getResponse = client.Get<Document>(descriptor => descriptor.Id(1));

        //getResponse -> still can read from index

        var acknowledgedResponse2 = client.UpdateSettings(descriptor => descriptor.Index(indexName).BlocksWrite(false));

        var indexResponse2 = client.Index(documentToAdd);

        //indexResponse2 -> now I can add new document to my index

        Console.ReadKey();
    }
}

public class Document
{
    public int Id { get; set; }
    public string Name { get; set; }
}