ElasticSearch索引不能正常工作/可靠 [英] ElasticSearch index exists not working / reliable

问题描述

我正在ElasticSearch的管理客户端上编写一个简单的Java包装器。要测试它，我有一个主要的方法，首先检查索引是否存在（IndicesExistsRequest），如果删除它（DeleteIndexRequest），并再次创建索引。见下面的代码。然而，我一直得到一个IndexAlreadyExistsException。

顺便说一下，我试图从命令提示符开始的节点获取一个客户端（通过简单的键入弹性搜索 ）。我已经在nodeBuilder的流畅界面上尝试过各种方法的组合，但我似乎无法获得一个。

  public static void main （String [] args）{
 ElasticSearchJavaClient esjc = new ElasticSearchJavaClient（nda）; 
 if（esjc.indexExists（））{
 esjc.deleteIndex（）; 
} 
 esjc.createIndex（）; 
 URL url = SchemaCreator.class.getResource（/ elasticsearch / samples.type.json）; 
 String mappings = FileUtil.getContents（url）; 
 esjc.createType（samples，映射）; 
} 
 
 final客户端esClient; 
 final IndicesAdminClient adminClient; 
 final String indexName; 
 
 public ElasticSearchJavaClient（String indexName）{
 this.indexName = indexName; 
 esClient = nodeBuilder（）。clusterName（elasticsearch）。client（true）.node（）。client（）; 
 adminClient = esClient.admin（）。indexes（）; 
} 
 
 public boolean deleteIndex（）{
 logger.info（删除索引+ indexName）; 
 DeleteIndexRequest request = new DeleteIndexRequest（indexName）; 
 try {
 DeleteIndexResponse response = adminClient.delete（request）.actionGet（）; 
 if（！response.isAcknowledged（））{
 throw new Exception（无法删除索引+ indexName）; 
} 
 logger.info（Index deleted）; 
返回true; 
} catch（IndexMissingException e）{
 logger.info（No such index：+ indexName）; 
返回false; 
} 
} 
 
 public boolean indexExists（）{
 logger.info（String.format（验证索引的存在\％s\ ，indexName））; 
 IndicesExistsRequest request = new IndicesExistsRequest（indexName）; 
 IndicesExistsResponse response = adminClient.exists（request）.actionGet（）; 
 if（response.isExists（））{
 logger.info（Index exists）; 
返回true; 
} 
 logger.info（No such index）; 
返回false; 
} 
 
 public void createIndex（）{
 logger.info（创建索引+ indexName）; 
 CreateIndexRequest request = new CreateIndexRequest（indexName）; 
 IndicesAdminClient iac = esClient.admin（）。indexes（）; 
 CreateIndexResponse response = iac.create（request）.actionGet（）; 
 if（！response.isAcknowledged（））{
 throw new Exception（无法删除索引+ indexName）; 
} 
 logger.info（创建索引）; 
} 
  

解决方案

解。由于java客户端的调用是异步完成的，因此您必须使用采用动作侦听器的变体。尽管如此，解决方案仍然有一些变化：

  //内部类，因为它刚刚被抛出
 //动作侦听器实现来表示
 //索引存在
 private class ExistsException extends RuntimeException {
} 
 
 public boolean exists（）{
 logger.info（String.format（验证索引的存在\％s\，indexName））; 
 IndicesExistsRequest request = new IndicesExistsRequest（indexName）; 
 try {
 adminClient.exists（request，new ActionListener< IndicesExistsResponse>（）{
 public void onResponse（IndicesExistsResponse response）{
 if（response.isExists（））{
抛出新的ExistsException（）; 
} 
} 
 public void onFailure（Throwable e）{
 ExceptionUtil.smash（e）; 
} 
}）; 
} 
 catch（ExistsException e）{
 return true; 
} 
返回false; 
} 
  

I am writing a simple Java wrapper around ElasticSearch's admin client. To test it I have a main method that first checks if an index exists (IndicesExistsRequest), if so deletes it (DeleteIndexRequest), and creates the index again. See code below. Yet I consistently get an IndexAlreadyExistsException.

By the way I am trying to get a client for the node that you start from the command prompt (by simply typing "elastic search"). I have tried every combination of methods on nodeBuilder's fluent interface, but I can't seem to get one.

public static void main(String[] args) {
    ElasticSearchJavaClient esjc = new ElasticSearchJavaClient("nda");
    if (esjc.indexExists()) {
        esjc.deleteIndex();
    }
    esjc.createIndex();
    URL url = SchemaCreator.class.getResource("/elasticsearch/specimen.type.json");
    String mappings = FileUtil.getContents(url);
    esjc.createType("specimen", mappings);
}

final Client esClient;
final IndicesAdminClient adminClient;
final String indexName;

public ElasticSearchJavaClient(String indexName) {
    this.indexName = indexName;
    esClient = nodeBuilder().clusterName("elasticsearch").client(true).node().client();
    adminClient = esClient.admin().indices();
}

public boolean deleteIndex() {
    logger.info("Deleting index " + indexName);
    DeleteIndexRequest request = new DeleteIndexRequest(indexName);
    try {
        DeleteIndexResponse response = adminClient.delete(request).actionGet();
        if (!response.isAcknowledged()) {
            throw new Exception("Failed to delete index " + indexName);
        }
        logger.info("Index deleted");
        return true;
    } catch (IndexMissingException e) {
        logger.info("No such index: " + indexName);
        return false;
    }
}

public boolean indexExists() {
    logger.info(String.format("Verifying existence of index \"%s\"", indexName));
    IndicesExistsRequest request = new IndicesExistsRequest(indexName);
    IndicesExistsResponse response = adminClient.exists(request).actionGet();
    if (response.isExists()) {
        logger.info("Index exists");
        return true;
    }
    logger.info("No such index");
    return false;
}

public void createIndex() {
    logger.info("Creating index " + indexName);
    CreateIndexRequest request = new CreateIndexRequest(indexName);
    IndicesAdminClient iac = esClient.admin().indices();
    CreateIndexResponse response = iac.create(request).actionGet();
    if (!response.isAcknowledged()) {
        throw new Exception("Failed to delete index " + indexName);
    }
    logger.info("Index created");
}

解决方案

OK, I figured out a solution. Since the java client's calls are done asynchronously you have to use the variant which takes an action listener. The solution still gets a bit contrived though:

// Inner class because it's just used to be thrown out of
// the action listener implementation to signal that the
// index exists
private class ExistsException extends RuntimeException {
}

public boolean exists() {
    logger.info(String.format("Verifying existence of index \"%s\"", indexName));
    IndicesExistsRequest request = new IndicesExistsRequest(indexName);
    try {
        adminClient.exists(request, new ActionListener<IndicesExistsResponse>() {
            public void onResponse(IndicesExistsResponse response) {
                if (response.isExists()) {
                    throw new ExistsException();
                }
            }
            public void onFailure(Throwable e) {
                ExceptionUtil.smash(e);
            }
        });
    }
    catch (ExistsException e) {
        return true;
    }
    return false;
}

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