Apache Hadoop

Monitor Apache Hadoop — NameNode health, DataNode disk usage, HDFS block counts, MapReduce job queues, and JVM GC — using the JMX Exporter.

Pattern: JMX Exporter agent → Prometheus scrape → xScaler remote_write

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Prerequisites

• Apache Hadoop 3.x
• Java 8+
• xScaler tenant credentials (token + tenant ID)

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Option A — Prometheus Exporter

Attach the JMX Exporter to NameNode and DataNode:

# Add to hadoop-env.sh
export HADOOP_NAMENODE_OPTS="$HADOOP_NAMENODE_OPTS \
  -javaagent:/opt/jmx_exporter.jar=9870:/etc/hadoop/jmx_nn.yml"

export HADOOP_DATANODE_OPTS="$HADOOP_DATANODE_OPTS \
  -javaagent:/opt/jmx_exporter.jar=9864:/etc/hadoop/jmx_dn.yml"

Add to prometheus.yml:

scrape_configs:
  - job_name: hadoop_namenode
    static_configs:
      - targets: ['namenode-host:9870']
  - job_name: hadoop_datanode
    static_configs:
      - targets: ['datanode1:9864', 'datanode2:9864']

remote_write:
  - url: https://euw1-01.m.xscalerlabs.com/api/v1/push
    authorization:
      credentials: <token>
    headers:
      X-Scope-OrgID: <tenant-id>

---

Option B — Grafana Alloy

prometheus.scrape "hadoop" {
  targets = [
    {"__address__" = "namenode-host:9870", job = "namenode"},
    {"__address__" = "datanode1:9864",     job = "datanode"},
  ]
  forward_to = [prometheus.remote_write.xscaler.receiver]
}

prometheus.remote_write "xscaler" {
  endpoint {
    url = "https://euw1-01.m.xscalerlabs.com/api/v1/push"
    authorization {
      type        = "Bearer"
      credentials = "<token>"
    }
    headers = { "X-Scope-OrgID" = "<tenant-id>" }
  }
}

---

Option C — OpenTelemetry Collector

receivers:
  jmx:
    jar_path: /opt/opentelemetry-jmx-metrics.jar
    endpoint: localhost:8004
    target_system: hadoop
    collection_interval: 30s

processors:
  batch:
    timeout: 10s

exporters:
  otlphttp/xscaler:
    endpoint: https://euw1-01.m.xscalerlabs.com
    headers:
      Authorization: "Bearer <token>"
      X-Scope-OrgID: "<tenant-id>"
    compression: gzip

service:
  pipelines:
    metrics:
      receivers:  [jmx]
      processors: [batch]
      exporters:  [otlphttp/xscaler]

---

Logs

Collect Hadoop NameNode, DataNode, and ResourceManager logs. Add the following to your Alloy config:

local.file_match "hadoop_logs" {
  path_targets = [{
    __address__ = "localhost",
    __path__    = "/opt/hadoop/logs/*.log",
    instance    = constants.hostname,
    job         = "integrations/hadoop",
  }]
}

loki.source.file "hadoop_logs" {
  targets    = local.file_match.hadoop_logs.targets
  forward_to = [loki.write.xscaler.receiver]
}

loki.write "xscaler" {
  endpoint {
    url = "https://euw1-01.l.xscalerlabs.com/api/v1/logs/push"

    http_client_config {
      authorization {
        type        = "Bearer"
        credentials = env("XSCALER_TOKEN")
      }
    }

    headers = { "X-Scope-OrgID" = env("XSCALER_TENANT_ID") }
  }
}

Key metrics

Metric	Description
hadoop_namenode_total_blocks	Total HDFS blocks
hadoop_namenode_total_files	Total files in HDFS
hadoop_namenode_capacity_remaining	HDFS available capacity
hadoop_namenode_dead_nodes	Number of dead DataNodes
hadoop_datanode_bytes_written	Bytes written by DataNode
hadoop_datanode_bytes_read	Bytes read by DataNode
hadoop_jvm_gc_count	JVM GC count