我正在尝试使用 Java SDK 1.x 从 CloudWatch 检索一些 Elasticache 指标。我有多个用于多种服务的类,除了 Elasticache 之外,它们都可以工作。此类会传递 Elasticache 节点列表以及开始时间和结束时间。对于每个节点,我尝试从 Elasticache 检索 30 分钟内的一些指标。但是,由于某种原因,我不断获得每个指标的值 0.0。我已确认 AWS 控制台中的指标不为空。这是我的代码:
public class ElastiCacheCWMetricsRetriever {
private final AmazonCloudWatch cloudWatchClient;
public ElastiCacheCWMetricsRetriever(AmazonCloudWatch cloudWatchClient) {
this.cloudWatchClient = cloudWatchClient;
}
public Map<String, Map<String, Object>> getElastiCacheMetrics(List<String> nodeNames,
String startTimeStr, String endTimeStr) {
Map<String, Map<String, Object>> elastiCacheMetricsMap = new HashMap<>();
try {
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
Date startTime = dateFormat.parse(startTimeStr);
Date endTime = dateFormat.parse(endTimeStr);
for (String nodeName : nodeNames) {
Map<String, Object> nodeMetrics = new HashMap<>();
nodeMetrics.put("SwapUsage", getAverageMetricValue("AWS/ElastiCache",
"SwapUsage", "CacheNodeId", nodeName, startTime, endTime));
Double SwapUsage = getSumMetricValue("AWS/ElastiCache", "SwapUsage",
"CacheNodeId", nodeName, startTime, endTime);
System.out.println("SwapUsage for " + nodeName + " is " +
String.valueOf(SwapUsage));
nodeMetrics.put("CurrentConnections", getSumMetricValue("AWS/ElastiCache",
"CurrConnections", "CacheNodeId", nodeName, startTime, endTime));
nodeMetrics.put("DatabaseMemoryUsagePercentage",
getAverageMetricValue("AWS/ElastiCache", "DatabaseMemoryUsagePercentage",
"CacheNodeId", nodeName, startTime, endTime) * 100.0);
nodeMetrics.put("EngineCPUUtilization",
getAverageMetricValue("AWS/ElastiCache", "EngineCPUUtilization",
"CacheNodeId", nodeName, startTime, endTime) * 100.0);
Double EngineCPUUtil = getAverageMetricValue("AWS/ElastiCache",
"EngineCPUUtilization", "CacheNodeId", nodeName, startTime, endTime) * 100.0;
System.out.println("EngineCPUUtilization for " + nodeName + " is " + String.valueOf(EngineCPUUtil));
elastiCacheMetricsMap.put(nodeName, nodeMetrics);
}
} catch (Exception e) {
System.out.println("Error in Elasticache" + e.getMessage());
}
return elastiCacheMetricsMap;
}
private double getAverageMetricValue(String namespace, String metricName, String
dimensionName, String dimensionValue, Date startTime, Date endTime) {
int period = calculatePeriod(startTime, endTime);
return getMetricValue(namespace, metricName, dimensionName, dimensionValue, startTime, endTime, period, "Average");
}
private double getSumMetricValue(String namespace, String metricName, String dimensionName, String dimensionValue, Date startTime, Date endTime) {
int period = calculatePeriod(startTime, endTime);
return getMetricValue(namespace, metricName, dimensionName, dimensionValue, startTime, endTime, period, "Sum");
}
private double getMetricValue(String namespace, String metricName, String dimensionName, String dimensionValue, Date startTime, Date endTime, int period, String statistic) {
try {
GetMetricStatisticsRequest request = new GetMetricStatisticsRequest()
.withNamespace(namespace)
.withMetricName(metricName)
.withDimensions(new Dimension().withName(dimensionName).withValue(dimensionValue))
.withStartTime(startTime)
.withEndTime(endTime)
.withPeriod(period)
.withStatistics(statistic);
GetMetricStatisticsResult result = cloudWatchClient.getMetricStatistics(request);
System.out.println("Result for " + dimensionValue + " is " + result.toString());
return result.getDatapoints().isEmpty() ? 0 : result.getDatapoints().get(0).getAverage();
} catch (Exception e) {
System.out.println("Error in Elasticache" + e.getMessage());
return 0;
}
}
private int calculatePeriod(Date startTime, Date endTime) {
long diffInSeconds = (endTime.getTime() - startTime.getTime()) / 1000;
int periods = (int) Math.ceil(diffInSeconds / 1800);
return (periods > 0) ? 1800 : 60;
}
}
我正在使用
System.out.println("SwapUsage for " + nodeName + " is " + String.valueOf(SwapUsage));
进行故障排除。我不知道下一步该看哪里。有什么想法/建议吗?
编辑:所以我对此进行了更多测试,并在
System.out.println("Result for " + dimensionValue + " is " + result.toString());
内添加了这一行 getMetricValue
。我得到的结果是Result for scrsquy-001 is {Label: EngineCPUUtilization,Datapoints: []}
。为什么它是空的,我怎样才能让它工作?
您检查过您的 IAM 吗? 确保用于创建 Amazon CloudWatch 客户端的 AWS IAM 用户或角色具有从 CloudWatch 读取 Elasticache 指标的必要权限。验证附加到用户或角色的 IAM 策略,以确保其具有 cloudwatch:GetMetricStatistics 的权限。
通过快速查看您的代码,我看不到任何明显的错误,但我确实注意到 getSumMetricValue 和 getAverageMetricValue 方法中的“MetricName”存在潜在问题。
您在代码中指定了“SwapUsage”和“CurrConnections”等指标名称,但 Elasticache 指标通常使用“SwapUsage:PerNode”和“CurrConnections:PerNode”等指标名称进行报告。这些是示例,实际的指标名称可能有额外的后缀来区分不同的节点。