Servers, containers, networks, kernel, observability.
Technical notes from the close of SMARTOUR: what it takes to move a multi-tenant Kubernetes system from lab prototype to verifiable deliverable, across headless portals and a standards-drift debt.
Read moreTechnical notes on multi-cluster orchestration with Kubernetes, Rancher, GitLab CE and Grafana for hosting the deliverables of a multi-partner research project.
Read moreAt KubeCon Seattle (December 2018) Grafana Labs presented Loki, an alpha-stage log aggregator that indexes only the labels of each stream and keeps the compressed content on object storage. Notes on the Cortex-derived architecture and on the cost-versus-search trade-off.
Read morePodman manages containers with a fork-exec model rather than a persistent daemon. Technical notes on the architecture, on rootless via user namespaces, and on current limits, at version 0.12.
Read moreOn 29 March 2017 the CNCF accepted containerd as an incubating project, while CRI-O matured in the Kubernetes incubator. Two answers to the Container Runtime Interface introduced in Kubernetes 1.5.
Read moreGrafana neither collects nor stores metrics: it queries external sources through data source plugins and draws dashboards. Technical notes on a decoupled architecture and on the Apache 2.0 licence.
Read moreWhen a region's data comes from heterogeneous sources, integration is decided on the choice of protocols. A survey of REST, gRPC, GraphQL, MQTT and the OGC standards as of January 2017.
Read moreTechnical notes on an open-source IaaS stack — OpenStack, OpenNebula, Eucalyptus — for the requirements of a tourism and cultural-heritage platform.
Read moreDocker, open-sourced by dotCloud in March 2013, puts a uniform interface over cgroups, namespaces and a union filesystem already present in the Linux kernel. What changes is not the kernel but the distribution format.
Read moreRFC 6455 standardised WebSocket in December 2011. The least obvious detail is the mandatory XOR masking of client-to-server frames: a rule born from a real attack on transparent proxies, not a stylistic choice.
Read moreOpenStack's third release, Cactus (15 April 2011), brings live migration to Nova and static serving to Swift. Technical notes on the compute architecture and on what is still missing before production.
Read moreLinkedIn open-sourced Kafka in January 2011. Instead of a queue with single-consumption delivery, it builds messaging on top of a persistent, partitioned log.
Read morePuppet 0.24, by Luke Kanies and Reductive Labs, describes a system's configuration as a set of resources with a desired state. Notes on its DSL, catalog, idempotency and agent/master architecture as they stand in 2009.
Read moreHow a visual editor for scientific workflows is translated into WS-BPEL executable on a Globus grid, and why the dataflow the biologist draws does not coincide with BPEL's web-service orchestration model.
Read moreTechnical notes on Xen paravirtualisation, live migration and the running cost of a server estate, written alongside a seminar on free software in public administration.
Read moreGlobus Toolkit 4 gives state to stateless web services with WSRF and delegates credentials with X.509 proxy certificates (RFC 3820). How the open-source grid middleware reuses existing standards instead of reinventing them.
Read moreTechnical notes on how a web portal plugs into the X.509 authentication of a computing grid, between Grid Security Infrastructure, RFC 3820 proxy certificates and accredited certification authorities.
Read moreTechnical notes on a master-slave architecture for a learned society's membership data: an authoritative LDAP directory on site, encrypted replication to a web front-end in hosting, an open-source stack.
Read moreFreeBSD ships kernel, userland and documentation in one source tree under the BSD licence. A technical note on the practical consequences of that model versus assembling a Linux distribution, as of the 4.8 release.
Read moreBash 2.05a is a free rewrite of the Bourne shell that extends POSIX.2. Writing portable scripts means choosing when to lean on the extensions and when to stop at the standard.
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