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Somewhat dated (2011), but an interesting read.

A Measurement Study of Server Utilization in Public CloudsHuan Liu, in Proc. Int. Conf. on Cloud and Green Computing (CGC), Sydney, Australia, Dec. 2011 extensive study of server CPU utilization across two different public cloud providers. To measure a cloud physical server’s utilization, we launch a small probing Virtual Machine (VM) (often the smallest VM offered) in a cloud provider, and then from within the VM, we monitor the CPU utilization of the underlying hardware machine. Since a cloud is built around multi-tenancy, there are several other VMs running on the same physical hardware. By measuring the underlying hardware’s CPU utilization, we measure the collective CPU utilization of other VMs sitting on the same hardware

Users of cloud services are presented with a bewildering choice of VM types and the choice of VM can have significant implications on performance and cost. In this paper we address the fundamental problem of accurately and economically choosing the best VM for a given workload and user goals. To address the problem of optimal VM selection, we present PARIS, a data-driven system that uses a novel hybrid offline and online data collection and modeling framework to provide accurate performance estimates with minimal data collection. PARIS is able to predict workload performance for different user-specified metrics, and resulting costs for a wide range of VM types and workloads across multiple cloud providers. When compared to a sophisticated baseline linear interpolation model using measured workload performance on two VM types, PARIS produces significantly better estimates of performance. For instance, it reduces runtime prediction error by a factor of 4 for some workloads on both AWS and Azure. The increased accuracy translates into a 45% reduction in user cost while maintaining performance.

P[lay]W[ith]D[ocker] is currently being used for different things such as:

  • Try new features fast as it’s updated with the latest dev versions.

  • Setup clusters in no-time and launch replicated services.

  • Learn through it’s interactive tutorials (

  • Give presentations in conferences or meetups.

  • Allow to run advanced workshops that’d usually require complex setups.

  • Collaborate with community members to diagnose and detect issues.

It’s our pride to present PWK (, our first iteration of a fully functional Kubernetes playground.


Kurt Marko:

By operating at different planes of abstraction, public cloud services and private cloud infrastructure make it virtually impossible to have a coherent, seamless hybrid cloud design. As organizations mature in their understanding and use of public services like AWS and move beyond simply treating them as rentable virtual server farms, they will internalize the public-private dichotomy and see that their hybrid cloud strategy has flaws. Until the industry better addresses the abstraction-layer mismatch, I expect to see more and more organizations rethinking their hybrid cloud plans.

OPA is a lightweight general-purpose policy engine that can be co-located with your service. You can integrate OPA as a sidecar, host-level daemon, or library.

Services offload policy decisions to OPA by executing queries. OPA evaluates policies and data to produce query results (which are sent back to the client). Policies are written in a high-level declarative language and can be loaded into OPA via the filesystem or well-defined APIs.


The Ship Show #46 podcast, The Epistemology of DevOps, originally published 13 August 2014, has many takeaways, generally focusing on issues associated with organizational and process "debt" that have little to do with the technical issues generally talked about in the "DevOps" context.


12 min:52 sec - Primary focus of the podcast starts about here

14:13 Kevin Behr makes a remark about sensing "restlessness about scaling" in the industry. This isn't directly about the organizational/process debt discussed later, but insightful since posts and tweets about scaling concerns are pervasive today and have clearly been a concern for some time.

16:53 Engineers want to know, "Is there an RFC for DevOps so I can use it like a tool?"

17:30 We don't need to standardize DevOps (so it can be productized and sold)

18:05 Developers: "If you ops people would just expose an API so we can interact with you like robots..."

18:25 DevOps is not about optimizing for developers

20:25 Culture is an abstraction we invent to represent interactions in a system

25:30 Taylor did atomistic science, focusing on the individual. Lean focuses on the system.

26:25 Science means we don't know, so we have to keep asking in a structured way. Once we know, we do engineering.

30:35 Almost no company teaches how to improve daily

37:10 The ability to transmit information among people is the limiting factor in most organizations

44:00 coal miners cross training for more productivity and safety through learning in a complex, dangerous environment

46:15 increase response repertoire

47:00 ITIL good for simple environments where things are constrained

51:00 Difficulties in creating emergent teams to deal with problems

51:40 Meetings to deal with problems diffuse responsibility and people think they provide safety

52:00 ephemeral crews to deal with dynamic capabilities; cross silos like cells with permeable walls

54:00 the pragmatic maxim

55:15 Explore it by Elisabeth Hendrickson

56:45 Heresy in Devops is ok

59:20 What's wrong with the enterprise today? Everything is a project. Actually, we're on a permanent change footing.

61:35 We're not resources, we're humans.

62:15 conversation ends