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Servers: SysAdmins, Kubernetes, OpenShift

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Server
  • Tales From The Sysadmin: Dumped Into The Grub Command Line

    Today I have a tale of mystery, of horror, and of hope. The allure of a newer kernel and packages was too much to resist, so I found myself upgrading to Fedora 30. All the packages had downloaded, all that was left was to let DNF reboot the machine and install all the new packages. I started the process and meandered off to find a cup of coffee: black, and darker than the stain this line of work leaves on the soul. After enough time had elapsed, I returned, expecting the warming light of a newly upgraded desktop. Instead, all that greeted me was the harsh darkness of a grub command line. Something was amiss, and it was bad.

    (An aside to the reader, I had this experience on two different machines, stemming from two different root problems. One was a wayward setting, and the other an unusual permissions problem.)

    How does the fledgling Linux sysadmin recover from such a problem? The grub command line is an inscrutable mystery to the uninitiated, but once you understand the basics, it’s not terribly difficult to boot your system and try to restore the normal boot process. This depends on what has broken, of course. If the disk containing your root partition has crashed, then sorry, this article won’t help.

  • Top Kubernetes Operators advancing across the Operator Capability Model

    At KubeCon North America 2019 we highlighted what it means to deliver a mature Kubernetes Operator. A Kubernetes Operator is a method of packaging, deploying and managing a Kubernetes application. The key attribute of an Operator is the active, ongoing management of the application, including failover, backups, upgrades and autoscaling, just like a cloud service.

    These capabilities are ranked into five levels, which are used to gauge maturity. We refer to this as the Operator Capability Model, which outlines a set of possible capabilities that can be applied to an application. Of course, if your app doesn’t store stateful data, a backup might not be applicable to you but log processing or alerting might be important. The important user experience that the Operator model aims for is getting that cloud-like, self-managing experience with knowledge baked in from the experts.

  • Red Hat simplifies transition to open source Kafka with new service registry and HTTP bridge

    Red Hat continues to increase the features available for users looking to implement a 100% open source, event-driven architecture (EDA) through running Apache Kafka on Red Hat OpenShift and Red Hat Enterprise Linux. The Red Hat Integration Q4 release provides new features and capabilities, including ones aimed at simplifying usage and deployment of the AMQ streams distribution of Apache Kafka.

    [...]

    In addition to the registry itself, users can leverage the included custom Kafka serializers and deserializers (SerDes). These SerDes Java classes allow Kafka applications to pull relevant schemas from the Service Registry instead of requiring the schemas to be bundled with the applications.

    Correspondingly, the registry has its own REST API to create, update, and delete artifacts as well as managing global and per-artifact rules. The registry API is compatible with another Kafka provider’s schema registry to facilitate a seamless migration to AMQ Streams as a drop-in replacement.

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