DC/OS 1.9.4

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DC/OS 1.9 includes many new capabilities for Operators, and expands the collection of Data and Developer Services with a focus on:

  • Tools for Production Operations - Monitoring and troubleshooting for distributed apps.
  • Broader Workload Support - From traditional apps to machine learning.
  • New data and developer services.


What's New

Apache Mesos 1.2.2 and Marathon 1.4.7 integrated

  • Marathon 1.4.7 release notes.
  • Apache Mesos 1.2.2 CHANGELOG. We also include some patches from the forthcoming Apache Mesos 1.2.3 release.

Container Orchestration

Added support for pods, GPUs, and made significant scalability improvements.


Multiple co-located containers per instance, scheduled on the same host. For more information, see the documentation.


  • Leverage GPUs to run novel algorithms.
  • Because DC/OS GPU support is compatible with nvidia-docker, you can test locally with nvidia-docker and then deploy to production with DC/OS.
  • Allocate GPUs on a per container basis, including isolation guarantees

For more information, see the documentation.

DC/OS Monitoring and Operations

Remote Process Injection for Debugging

The new dcos task exec command allows you to remotely execute a process inside the container of a deployed Mesos task, providing the following features.

  • An optional --interactive flag for interactive sessions.
  • Attach to a remote pseudoterminal (aka PTY) inside a container via the optional --tty flag.
  • Combine the --interactive and --tty flags to launch an interactive bash session or to run top and see the resource usage of your container in real time.

For more information, see the documentation for the debugging documentation.


Stream task and system logs to journald by setting the mesos_container_log_sink install-time parameter to journald or journald+logrotate. This allows you to:

  • Include task metadata like container ID in your queries to more easily locate the logs that you want.
  • Use new DC/OS CLI commands dcos node log and dcos task log DC/OS CLI commands to query the logs. You can also make requests directly against the new Logging API.
  • Set up log aggregation solutions such as Logstash to get logs into their aggregated storage solutions.

For more information, see the documentation.


  • Node-level HTTP API that returns metrics from frameworks, cgroup allocations per container, and host level metrics such as load and memory allocation.
  • StatsD endpoint in every container for forwarding metrics to the DC/OS metrics service. This service is what exposes the HTTP API.
  • Any metric sent to STATSD_UDP_HOST/PORT is available in the HTTP API /container/<container_id>/app endpoint.

For more information, see the documentation.

Tool for Troubleshooting Service Deployment Failures

  • The new service deployment troubleshooting tool allows you to find out why your applications aren’t starting from the GUI and CLI.

    Service deploy GUI

Improved GUI

  • New look and feel and improved navigation.

    New GUI

  • Usability improvements to the service create workflow.

    Improved GUI

Networking Services

  • CNI support for 3rd party CNI plugins.
  • Performance improvements across all networking features.

Other Improvements

DC/OS Internals

  • Update DC/OS internal JDK to 8u112 for security fixes.
  • Update DC/OS internal Python from 3.4 to 3.5.
  • The dcos_generate_config.sh --aws-cloudformation command will now determine the region of the s3 bucket automatically, preventing region mistakes.
  • Added the dcos_add_user.py script, which you can use to add or invites users to a DC/OS cluster from the command line. For more information, see the documentation.
  • Added dcos-shell which activates the DC/OS environment for running other DC/OS command line tools.

Expanded OS Support

Expanded Docker Engine Support

  • Docker 1.12 and 1.13 are now supported. Docker 1.13 is the default version.


Improved upgrade tooling and experience for on-premise installations. Upgrades now use internal DC/OS APIs to ensure nodes can be upgraded with minimal disruption to running DC/OS services on a node. The upgrade procedure has also been simplified to improve user experience.

For more information, see the documentation.

Known Issues and Limitations

  • DCOS_OSS-691 - DNS becomes briefly during DC/OS version upgrades.
  • DCOS-14005 - Marathon-LB does not support pods.
  • DCOS-14021 - Task logging to journald disabled by default, so task logs will continue to be written to their sandboxes, and logrotated out. The dcos task log command will work as it did before.
  • Marathon-7133 - Marathon application history is lost after Marathon restart.
  • CORE-1191 - The Mesos master's event queue can get backlogged with the default settings, causing performance problems. These can be mitigated by setting the following configuration parameter in your config.yaml file at install time. See the Configuration Reference for more information. Note: Lowering this parameter also reduces the number of tasks per framework that the dcos task subcommands can access for debugging. If you run a framework with many short tasks, such as Spark, you may not want to reduce this value.

    mesos_max_completed_tasks_per_framework: 20

Issues Fixed Since 1.8

  • CORE-735 - Large node count leads to failed overlay config and failed replog recovery.
  • DCOS-9149 - Missing Timeout for Spartan fetching DNS Exhibitor data.
  • DCOS-9754 - beam.smp consumes inordinate amount of CPU.
  • DCOS-9776 - Race in DeploymentPlan.
  • DCOS-10089 - Network tab in UI doesn't show the assigned IP.
  • DCOS-13228 - Layer 4 load balancer is not working with Docker bridge mode.
  • DCOS-13359 - Backends are not removed from VIP table when killed.
  • DCOS-13367 - ZooKeeper logs grow unbounded and will cause master node disks to fill up.
  • DCOS-13400 - Layer 4 load balancer cannot handle multiple protocols with the same VIP.
  • DCOS-13448 - Missing explicit file descriptor limits for DC/OS services.
  • DCOS-13672 - Mesos reports over allocated CPU during DC/OS upgrade.
  • DCOS-14228 - Disabled schedules keep firing in jobs.

Issues Fixed Since 1.9.1

  • Critical fix: Enables editing Marathon app in the UI. Encompasses the following:
    • DCOS_OSS-1350 - Nodes Page error on checkbox.
    • DCOS-17262 - Bug in DC/OS 1.9.1 - cannot edit marathon app from UI form.
    • DCOS-17242 - UI Bug - No warning when trying to create a service without specifying an ID.
    • DCOS-17241 - UI Bug in DC/OS 1.9.1 - Unable to select a task.
  • Fix for dcos-metrics dropping data. Encompasses the following:
    • DCOS-16350 - dcos-metrics drops nearly all app data.
    • DCOS-15939 - Long labels can cause errors in datadog plugin for dcos-metrics.
    • DCOS-16424 - Metrics plugins don't collect app-level metrics.
  • Ability to override storage region in AWS templates/ Encompasses the following:
    • DCOS-16737 - Unable to build and publish AWS templates to govcloud regions.
  • Fix for bug in persistent volume handling in the Mesos containerizer. Encompasses:
    • MESOS-7770 - Persistent volume might not be mounted if there is a sandbox volume whose source is the same as the target of the persistent volume.
  • Fix for agent failure with Docker 1.12 and Docker 1.13. Encompasses:
    • MESOS-7777 - Agent failed to recover due to mount namespace leakage in Docker 1.12/1.13.
  • DCOS-14880 - GUI bug: container type must be defined.

Issues Fixed Since 1.9.2

  • DCOS-15771 - mesos-dns doesn't return all SRV records of running tasks.
  • DCOS-16151 - Marathon Endpoints are not responding.
  • DCOS-16743 - libprocess in infinity schedulers performs a hostname reverse lookup instead of using /opt/mesosphere/bin/detect_ip.
  • DCOS-17271 - dcos-epmd failing after host reboot.
  • DCOS-17286 - Backport DCOS-16358 to 1.9.3.
  • DCOS-17294 - Unable to curl (resolve) applications using Mesos DNS names.
  • DCOS-18162 - dcos task exec does not pass on the last exit code.
  • DCOS_OSS-1234 - VIP docs mention no longer existing endpoint.
  • DCOS_OSS-1301 - Exhibitor doesn't log multiline messages to journald.
  • DCOS_OSS-1433 - Bug in /etc/systemd/system/dcos-docker-gc.service script (1.9).
  • DCOS_OSS-1451 - Stale datapoints can occur in container metrics.
  • DCOS_OSS-1466 - Marathon returns persistent 503's.
  • DCOS_OSS-1470 - Exhibitor: use PatternLayoutEscaped logger layout for structured journal logger.
  • DCOS_OSS-1486 - Metrics agent crashes when the mesos containers endpoint is missing fields.
  • DCOS_OSS-1561 - Revert DCOS_OSS-1472 from 1.9.3.

Issues Fixed Since 1.9.3

  • MESOS-7926 - Abnormal termination of default executor can cause MesosContainerizer::destroy to fail.
  • MESOS-7934 - OOM due to LibeventSSLSocket send incorrectly returning 0 after shutdown.