Question

我正在使用Amazon Cloud Watch服务为我的应用程序构建一个小型日志跟踪器。这个想法不是跟踪文件的日志输出，而是使用aws控制台的搜索引擎来查找日志信息。

我正在使用：

Eclipse as IDE
Java 8
依赖关系：aws-java-sdk-core / aws-java-sdk-cloudwatch V 1.10.49

另一方面，我有以下AWS配置：

访问和私钥
地区：加利福尼亚州
日志组：demo1
日志流：stream1

我正在编写以下代码来进行简单的功能测试：

package com.test.pe.cloudwatch;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Calendar;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.logs.AWSLogsClient;
import com.amazonaws.services.logs.model.InputLogEvent;
import com.amazonaws.services.logs.model.PutLogEventsRequest;
import com.amazonaws.services.logs.model.PutLogEventsResult;
import com.test.pe.base.CredentialBuilder; 

public class RegisterLog {
    private static String LOG_GROUP = "demo1";
    private static String LOG_STREAM = "stream1";

    public static void main(String[] args) throws ParseException {
        // building my credential and calendar instances
        AWSCredentials credential = CredentialBuilder.getCredential();
        Calendar calendar = Calendar.getInstance();
        // building a cloud watch log client
        AWSLogsClient cloudWatchlog = new AWSLogsClient(credential);
        cloudWatchlog.setRegion(Region.getRegion(Regions.US_WEST_1));
        // building a put request log
        PutLogEventsRequest request = new PutLogEventsRequest();
        request.setLogGroupName(LOG_GROUP);
        request.setLogStreamName(LOG_STREAM);
        // building my log event
        InputLogEvent log = new InputLogEvent();
        log.setMessage("Some message for a test");
        log.setTimestamp(calendar.getTimeInMillis());
        // building the array list log event
        ArrayList<InputLogEvent> logEvents = new ArrayList<InputLogEvent>();
        logEvents.add(log);
        // setting the error array list
        request.setLogEvents(logEvents);
        // make the request
        cloudWatchlog.putLogEvents(request);

        System.out.println("done!");
    }
}

当我第一次运行代码时，所有都是okey，消息保存成功。

然而，当我第二次执行代码时，我得到以下异常：

Exception in thread "main" com.amazonaws.services.logs.model.InvalidSequenceTokenException: The given sequenceToken is invalid. The next expected sequenceToken is: xxxxxxxxxxxxxxxxxxxxxxxxxxx (Service: AWSLogs; Status Code: 400; Error Code: InvalidSequenceTokenException; Request ID: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)
    at com.amazonaws.http.AmazonHttpClient.handleErrorResponse(AmazonHttpClient.java:1389)

XXXXXXXXXXX：是亚马逊生成的令牌代码。

阅读亚马逊文档，我发现了以下信息：

请求语法：

{
    "LogEvents": [
        {
            "Message": "string",
            "Timestamp": number
        }
    ],
    "LogGroupName": "string",
    "LogStreamName": "string",
    "SequenceToken": "string"
}

SequenceToken

A string token that must be obtained from the response of the previous PutLogEvents request.

Type: String

Length constraints: Minimum length of 1.

Required: No

amazon documentation about cloud watch log REST API

我决定在我的代码上硬编码序列标记，如下所示：

request.setSequenceToken("58523.......");

工作正常。我只是为了测试而做的。

最后，我发现获取序列令牌的唯一方法是。

PutLogEventsResult response = cloudWatchlog.putLogEvents(request);
String token = response.getNextSequenceToken();

如何在提出请求之前验证并获取序列代码？我无法在文档中找到它。

Answer 1

当你调用putLogEvents（getNextSequenceToken）时，通常会得到nextToken。如果有多个生产者推送到流，他们正在竞争，并且其中只有一个可以一次推送（即：如果你得到一个令牌，而其他人推送它会使你的令牌无效）。

如果发生这种情况，您需要描述流并获取新令牌：https://github.com/OctopusDeploy/OctopusDeploy-Api/wiki/Releases

所以模式是： 1）如果您没有有效的令牌或根本没有令牌（您刚刚开始），请描述该流以找出令牌。 2）推动你使用的令牌。如果推送成功，则更新令牌 3）如果推送不成功，请转到1），获取新令牌并重试。如果有多个生产者，您可能需要多次尝试（即循环）。

Answer 2

我遇到了同样的问题并使用以下方法解决了这个问题：

String token = logStream.getUploadSequenceToken();

完整的源代码：

 public CloudWatchHandler(String logGroupName, String logStreamName) {
     credentials = new DefaultAWSCredentialsProviderChain().getCredentials();
     awsLogsClient = new AWSLogsClient(credentials);
     awsLogsClient.setRegion(Region.getRegion(Regions.US_WEST_2));
     this.logGroupName = logGroupName;
     this.logStreamName = logStreamName;
     logStreamsRequest = new DescribeLogStreamsRequest(logGroupName);
     logStreamList = new ArrayList<LogStream>();         
     putLogEventsRequest = new PutLogEventsRequest(); 
     putLogEventsResult = new PutLogEventsResult();

 }

 public void log(String message) {
     logEvents = new ArrayList<InputLogEvent>();
     log = new InputLogEvent();
     calendar = Calendar.getInstance(); 

     log.setTimestamp(calendar.getTimeInMillis());
     log.setMessage(message);
     logEvents.add(log);

     logStreamsRequest.withLimit(5);
     logStreamList= awsLogsClient.describeLogStreams(logStreamsRequest).getLogStreams(); 

     for (LogStream logStream: logStreamList) {
         if (logStream.getLogStreamName().equals(logStreamName))
             token = logStream.getUploadSequenceToken();
     }  

     if (token!=null) {
         putLogEventsRequest.setLogGroupName(logGroupName);
         putLogEventsRequest.setLogStreamName(logStreamName);
         putLogEventsRequest.setLogEvents(logEvents);

         putLogEventsRequest.setSequenceToken(token);
         putLogEventsResult = awsLogsClient.putLogEvents(putLogEventsRequest); 
     }       
 }

Answer 3

我目前发布的代码仍然存在一些问题，因此我将添加我的工作解决方案来帮助解决问题：

"logStream.getLogStreamName()"返回的不仅仅是流的名称，因此我使用DescribeLogStreamsRequest().withLogGroupName("myCrAzYLogGroup");

获取了流

//creds
        String awsAccessKey = System.getProperty("AWS_ACCESS_KEY_ID");
        String awsSecretKey = System.getProperty("AWS_SECRET_ACCESS_KEY");
        Calendar calendar = Calendar.getInstance();
        AWSCredentials credential = new BasicAWSCredentials(awsAccessKey, awsSecretKey);
        AWSLogsClient awsLogsClient = new AWSLogsClient(credential);
        awsLogsClient.setRegion(Region.getRegion(Regions.US_WEST_2));

        //only difference in my code (i wanted to point out) is the use of BasicAWSCredentials
        //AWSCredentials credential = CredentialBuilder.getCredential();
        //AWSLogsClient cloudWatchlog = new AWSLogsClient(credential);

        PutLogEventsRequest putLogEventsRequest = new PutLogEventsRequest(); 
        putLogEventsRequest.setLogGroupName("myCrAzYLogGroup");
        putLogEventsRequest.setLogStreamName("myCrAzYLogStream");

        String token = null;
        //here's mainly what I changed 
        DescribeLogStreamsRequest logStreamsRequest = new DescribeLogStreamsRequest().withLogGroupName("myCrAzYLogGroup");
        List<LogStream> logStreamList = new ArrayList<LogStream>();
        logStreamList= awsLogsClient.describeLogStreams(logStreamsRequest).getLogStreams();

        //the answer to this question (get the token and use it)
        //keep in mind I'm not comparing because I only have one stream
        //again this is just to help get started/trouble shoot with a simplified setup
        for (LogStream logStream: logStreamList) {
            token = logStream.getUploadSequenceToken();
        }
        if(token != null)
        {
            putLogEventsRequest.setSequenceToken(token);
        }
        InputLogEvent testEvent = new InputLogEvent();
        testEvent.setMessage("let's test this log!");
        testEvent.setTimestamp(calendar.getTimeInMillis());
        ArrayList<InputLogEvent> logEvents = new ArrayList<InputLogEvent>();
        logEvents.add(testEvent);
        putLogEventsRequest.setLogEvents(logEvents);

        PutLogEventsResult putLogEventsResult = new PutLogEventsResult();
         //this will return the next token if you want to hold onto it
        putLogEventsResult = awsLogsClient.putLogEvents(putLogEventsRequest);

Amazon Cloud Watch Log - PutLogEventsRequest - 给定的sequenceToken无效

3 个答案: