Azure Cosmos DB for Gremlin 服务器响应头

适用对象： Gremlin

本文介绍了执行请求时 Azure Cosmos DB for Gremlin 服务器返回给调用方的标头。 这些标头可用于排查请求性能问题，生成与 Azure Cosmos DB 服务进行本机集成的应用程序，以及简化客户支持。

请记住，如果依赖这些标头，应用程序到其他 Gremlin 实现的可移植性将会受到限制。 好处是能够与 Azure Cosmos DB for Gremlin 更紧密地集成。 这些标头不属于 TinkerPop 标准。

标头

状态代码

下面列出了服务器为 x-ms-status-code 状态属性返回的最常见代码。

示例

基于 Gremlin.Net 的、可读取一个状态属性的示例客户端应用程序：

// Following example reads a status code and total request charge from server response attributes.
// Variable "server" is assumed to be assigned to an instance of a GremlinServer that is connected to Azure Cosmos DB account.
using (GremlinClient client = new GremlinClient(server, new GraphSON2Reader(), new GraphSON2Writer(), GremlinClient.GraphSON2MimeType))
{
  ResultSet<dynamic> responseResultSet = await GremlinClientExtensions.SubmitAsync<dynamic>(client, requestScript: "g.V().count()");
  long statusCode = (long)responseResultSet.StatusAttributes["x-ms-status-code"];
  double totalRequestCharge = (double)responseResultSet.StatusAttributes["x-ms-total-request-charge"];

  // Status code and request charge are logged into application telemetry.
}

演示如何从 Gremlin Java 客户端读取状态属性的示例：

try {
  ResultSet resultSet = this.client.submit("g.addV().property('id', '13')");
  List<Result> results = resultSet.all().get();

  // Process and consume results

} catch (ResponseException re) {
  // Check for known errors that need to be retried or skipped
  if (re.getStatusAttributes().isPresent()) {
    Map<String, Object> attributes = re.getStatusAttributes().get();
    int statusCode = (int) attributes.getOrDefault("x-ms-status-code", -1);

    // Now we can check for specific conditions
    if (statusCode == 409) {
        // Handle conflicting writes
      }
    }

    // Check if we need to delay retry
    if (attributes.containsKey("x-ms-retry-after-ms")) {
      // Read the value of the attribute as is
      String retryAfterTimeSpan = (String) attributes.get("x-ms-retry-after-ms"));

      // Convert the value into actionable duration
			LocalTime locaTime = LocalTime.parse(retryAfterTimeSpan);
			Duration duration = Duration.between(LocalTime.MIN, locaTime);

      // Perform a retry after "duration" interval of time has elapsed
    }
  }
}

后续步骤

• Azure Cosmos DB 的 HTTP 状态代码
• 常见的 Azure Cosmos DB REST 响应标头
• TinkerPop 图形驱动程序提供程序要求