Issues Identified in MMCloud Carmel 2.0 Release

Known Issues and Limitations

  • Single authentication cookie for all RStudio servers connected to one gateway

    When a browser starts an RStudio session, an authentication cookie is cached on the browser. The cookie identifies the username and the IP address associated with the RStudio server, but not the port. When a single browser attaches to multiple RStudio servers connected to one gateway, only one authentication cookie is cached. This causes problems if each RStudio session has a different username and password.

    The workaround is to:
    • Use the same username and password for all RStudio servers connected to one gateway, or
    • Use a different browser for each RStudio session, or
    • Connect each RStudio server to its own gateway
  • Concurrent use of multiple container images can cause the image cache to reach its maximum capacity

    Default behavior is to use an EBS volume as the image cache. If many large images are used in a short period of time, the cache can reach capacity. The workaround is to use the float image cache -d command to remove images from the cache or to use an s3 bucket as the image cache.

  • Job script ignored if image has entrypoint

    ENTRYPOINT is an instruction used when building a container image to configure an executable that will automatically run as soon as the container starts. If a container with an entrypoint is included in a float submit command, any job script included in the float submit command is ignored. The workaround is to build a new container image that excludes the entrypoint.

  • No upper limit on resource capacity when attempting to migrate to larger VM instances

    The job migration policy specifies when a job should migrate and what the step-up (or step-down) in resource capacity should be. However, the available VM instances have an upper limit on resource capacity and job migration takes longer as the memory footprint increases. The current WaveRider algorithm does not incorporate this information.