Setup Monitoring Using Apache Zookeeper and OpenTelemetry

In this article, I’ll show you a simplified way to configure a critical open-source component, Zookeeper. Monitoring Zookeeper applications helps to ensure that the data sets are distributed as expected across the cluster. Although Zookeeper is considered very resilient to network mishaps, it’s inevitable that you will want to monitor the server. To do this, I’ll be using the Zookeeper receiver from OpenTelemetry.

The configuration detailed in this post uses observIQ’s distribution of the OpenTelemetry collector, which simplifies the use of OpenTelemetry for all users. You can take a look at the details of this support .

You can utilize this receiver in conjunction with any OTel collector: including the OpenTelemetry Collector and observIQ’s distribution of the collector.

Monitoring performance metrics for Zookeeper is necessary to ensure that all the jobs are running as expected and the clusters are humming. The following metrics categories are monitored using this configuration:

Znodes

You can automatically discover Zookeeper Clusters, monitor memory (heap and non-heap) on the Znode, and get alerts of changes in resource consumption. You can also automatically collect, graph, and get alerts on garbage collection iterations, heap size and usage, and threads. ZooKeeper hosts are deployed in a cluster, and as long as a majority of hosts are up, the service will be available. Note that you must ensure the total node count inside the ZooKeeper tree is consistent.

Latency and Throughput

This metric will provide a consistent view of the performance of your servers, regardless of whether they change roles from Followers to Leader or back you will get a meaningful view of the history.

Configuring the Zookeeper Receiver

After the installation, the config file for the collector can be found at:

• C:\Program Files\observIQ OpenTelemetry Collector\config.yaml (Windows)

• /opt/observiq-otel-collector/config.yaml (Linux)

  
  

Receiver Configuration:

1. Configure the collection_interval attribute. It is set to 60 seconds in this sample configuration.
2. Set up the endpoint attribute as the system that is running the Hadoop instance

receivers:
  zookeeper:
    collection_interval: 30s
    endpoint: localhost:2181

Processor Configuration:

1. The resource detection processor is used to create a distinction between metrics received from multiple Hadoop systems. This helps with filtering metrics from specific Redis hosts in the monitoring tool, in this case, Google Cloud operations.

2. Add the batch processor to bundle the metrics from multiple receivers. We highly recommend using this processor in the configuration, especially for the benefit of the logging component of the collector. To learn more about this processor .

   
   

processors:
  resourcedetection:
    detectors: ["system"]
    system:
      hostname_sources: ["os"]

  batch:

Exporter Configuration:

In this example, the metrics are exported to New Relic using the OTLP exporter. If you would like to forward your metrics to a different destination, check the destinations that OpenTelemetry supports at this time, .

exporters:
  otlp:
    endpoint: //otlp.nr-data.net:443
    headers:
      api-key: 00000-00000-00000
    tls:
      insecure: false

Set up the pipeline:

service:
  pipelines:
    metrics:
      receivers:
      - zookeeper
      processors:
      - resourcedetection
      - batch
      exporters:
      - otlp

Viewing the Metrics

All the metrics the Zookeeper receiver scrapes are listed below.

Metric	Description
zookeeper.connection.active	The number of active connections.
zookeeper.data_tree…hemeral_node.count	The number of ephemeral nodes.
zookeeper.data_tree.size	The size of the data tree.
zookeeper.file_descriptor.limit	The limit set for the file descriptor.
zookeeper.file_descriptor.open	The number of open file descriptors
zookeeper.latency.max	The maximum latency
zookeeper.latency.min	The minimum latency set.
zookeeper.packet.count	The packet count
zookeeper.request.active	The number of active requests
zookeeper.watch.count	The watch count
zookeeper.znode.count	The total number of znode.

Alerting

Now that you have the metrics gathered and exported to the destination of your choice, you may want to explore how to configure alerts for these metrics effectively. Here are some alerting possibilities for ZooKeeper:

Alert	Severity
ZooKeeper server is down	critical
Too many znodes created	warning
Too many connections created	warning
Memory occupied by znode is too large	warning
Set too many watch	warning
Too many files open	warning
Average latency is too high	warning
JVM memory almost full	warning

As you can see, this is a simple way to implement the OpenTelemetry standards. Additionally, if you use the observIQ distribution, this provides a single-line installer and integrated receivers, exporter, and processor pool, making working with this collector an easy task.

Also Published