Publishing Custom Metrics

// Pass all the required user creds (Generated in pre-requisite step1) to AuthProvider.
 
AuthenticationDetailsProvider provider =
                SimpleAuthenticationDetailsProvider.builder()
                        .tenantId(TENANCY_ID)
                        .userId(USER_ID)
                        .fingerprint(FINGERPRINT)
                        .passPhrase(PASS_PHRASE)
                        .privateKeySupplier(
                                () -> {
                                    try {
                                        return new FileInputStream(PRIVATE_KEY_PATH);
                                    }
                                    catch (IOException ie) {
                                        throw new RuntimeException(
                                                String.format("Unable to find private key file %s", PRIVATE_KEY_PATH), ie);
                                    }
                                })
                        .build();
 
        MonitoringClient monitoringClient = new MonitoringClient(provider);
        monitoringClient.setRegion(REGION);
 
// Set the monitoring service end point : https://telemetry-xyz.com
 
        monitoringClient.setEndpoint(MONITORING_CLIENT_ENDPOINT);
        
// Fetch metrics using Ambari API. Pass all the required userInfo to get Metrics from Ambari metric API. 
   Here Url can be any service metrics url : https://<Ambari>:<port>/api/v1/clusters/ClusterName/services/HDFS/components/NAMENODE. 
   This API returns json as response. User can extract required metrics example metrics/jvm/memHeapCommittedM,metrics/jvm/memHeapUsedM; 
   convert it to any Object. Ex: Here it is  Map<url,Map<MetricName, MetricData>>
 
        Map<String, Map<String, MetricData>> metrics = getMetrics(url, sslContext, userInfo);
 
// Iterate over the metric data, construct the payload and push to monitoring service
 
        List<MetricDataDetails> metricDataDetailsList = new ArrayList<>();
        for (Map.Entry<String, Map<String, MetricData>> entry : metrics.entrySet()) {
            String url = entry.getKey();
            Map<String, MetricData> metricMap = entry.getValue();
            for (Map.Entry<String, MetricData> metricMapEntry : metricMap.entrySet()) {
                HashMap<String, String> dimensions = Maps.newHashMap();
                String metricName = metricMapEntry.getKey();
                MetricData md = metricMapEntry.getValue();
               // These dimensions can be used to filter metrics in OCI metric monitoring console
                dimensions.put("resourceId", md.getResourceId());
                dimensions.put("nodeHostName", md.getHostname());
                dimensions.put("metricType", md.getMetrictype()); // Can be Cluster/Host/Component/Host-Component.
                dimensions.put("clusterName", md.getClusterName());
                dimensions.put("serviceName", md.getServiceName()); // Ex: HDFS
                dimensions.put("componentName", md.getComponentName()); // Ex: DATANODE,NAMENODE
                metricDataDetailsList.add(MetricDataDetails.builder()
                        .namespace(METRIC_NAMESPACE) // This is the custom namespace where user wants to push the metrics
                        .compartmentId(COMPARTMENT_ID) // Compartment Id in tenancy.
//                        .resourceGroup("resourceGroup1") // optional, replace with your resource group
                        .name(metricName) // Name of the metric
                        .dimensions(dimensions) // Dimensions of metric like resourceId, hostname etc.,
                        .datapoints(Arrays.asList(Datapoint.builder().timestamp(md.getTimestamp())
                                .value(Double.valueOf(md.getValue())).count(1).build())) // data points like value, timestamp, 
                                   count of the metric.
                        .build());
            }
        }
 
// Create MetricData request.
        PostMetricDataRequest postMetricDataRequest =
                PostMetricDataRequest.builder()
                        .postMetricDataDetails(
                                PostMetricDataDetails.builder()
                                        .metricData(metricDataDetailsList)
                                        .build())
                        .build();
 
// Push the metrics to monitoring service using client.
 
        PostMetricDataResponse response = monitoringClient.postMetricData(postMetricDataRequest);
    }
 
// url is Ex:https://<Ambari>:<port>/api/v1/clusters/ClusterName/services/HDFS/components/NAMENODE. sslcontext, UserInfo objects to 
   communicate with Ambari server API.
   private String getMetrics(String url, SSLContext sslContext, UserInfo ambariServerInfo)
            throws IOException
    {
        URL obj = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
 
        con.setSSLSocketFactory(sslContext.getSocketFactory());
        con.setRequestMethod("GET");
        con.setRequestProperty("Authorization", "Basic " + encodeCredentials(ambariServerInfo.getUsername(), ambariServerInfo.getPassword()));
 
        int responseCode = con.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK) {
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String inputLine;
            StringBuffer response = new StringBuffer();
 
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();
 
            return response.toString();
        }
        else {
            throw new IOException("HTTP GET request failed with error code: " + responseCode);
        }
    }