Release Notes for 1.9.0 RC4

These are the release notes for DC/OS 1.9.0 Release Candidate 4.

DC/OS 1.9 includes many new capabilities 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.
  • Security - New CLI capabilities, enhanced LDAP support, and many small improvements.
  • New data and developer services.

Please try out the new features and updated services. Provide any feedback through our support channel:


Breaking Changes

The DC/OS Identity and Access Management (IAM) SAML Service Provider implementation no longer accepts transient subject NameIDs.

What’s New

Apache Mesos 1.2 and Marathon 1.4 integrated

Container Orchestration

  • Pods - Multiple co-located containers per instance, scheduled on the same host. For more information, see the documentation. Preview
  • GPU - Leverage GPUs to run novel algorithms. For more information, see the documentation. Preview
  • Significant scalability improvements.

DC/OS Monitoring and Operations

Remote Process Injection for Debugging Preview

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 dcos task exec command here.

Logging Preview

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 the new DC/OS CLI commands dcos node log and dcos task log to query logs. You can also make HTTP 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.

Metrics Preview

  • Node-level HTTP API that returns metrics from tasks, 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’s /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.

Security and Governance

  • DC/OS Identity and Access Management (IAM) highlights:

    • LDAP group import: support importing posixGroup objects according to RFC2307 and RFC2307bis, and ensure compatibility with FreeIPA and OpenLDAP.
    • SAML 2.0: ensure that the authentication flow works against Shibboleth and improve compatibility with a wide range of identity provider configurations.
    • OpenID Connect: ensure that the authentication flow works against dex as well as against Azure Active Directory, and allow for customizing the identity provider certificate verification in back-channel communication. Enhance configuration validation for a better user experience.
  • DC/OS CLI highlights:

    • Support single sign-on authentication via OpenID Connect and SAML 2.0 against the DC/OS IAM.
    • Support authentication with service account credentials.
  • Introduce various secrets improvements (for more information, see the secrets documentation).

  • Security hardening across the platform, including Mesos, Marathon, and Admin Router.

Developer Services

  • Jenkins

    • The Jenkins DC/OS service will now work with DC/OS clusters in strict mode.
    • Marathon plugin now supports service accounts, allowing easy automated and secure deploys to DC/OS clusters.

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 --aws-cloudformation command will now determine the region of the s3 bucket automatically, preventing region mistakes.
  • Added dcos-shell which activates the DC/OS environment for running other DC/OS command line tools.
  • Added the reset-superuser script which attempts to create or restore superuser privileges for a given DC/OS user.

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 unavailable 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.
  • DCOS-14433 - The Universal container runtime does not support Azure cloud with Ubuntu.
  • Marathon-7133 - Marathon application history is lost after Marathon restart.

Issues Fixed since 1.9.0-rc3

  • DCOS-OSS-743 - If you are using Docker 1.13 on CentOS 7.3, the custom CLI installation method fails while installing prerequisites (--install-prereqs).
  • DCOS-14047 - Marathon is killed during upgrades. This is expected behavior as of Marathon 1.3.6.
  • MARATHON-1713 - Volumes do not persist.