Besides clouds coming in different flavours (private, public, hybrid, as a infrastructure service, as a application delivery service), the basic cloud IT building block the cloud virtual server or machine also comes in many different flavours. Or exhibiting a great deal of elasticity, based on cloud servers now typically having multi-core CPUs and workload hypervisors that can span one or many CPU cores with different operating systems or OS images.
This has been, of course, a regular feature of mainframes for many years ago, and was brought into mainstream server computing accessible for many more with mini machines like DEC VAX-series, UNIX-based workstations and, in the Nordics, Norsk Data Sintran based computers for instance. Looking at the Intel-based server architectures with MS Windows Server OS that overtook these, one had initially 1 CPU (with one CPU core) associated with this one operating system, where the OS could multitask of shift jobs among databases and applications running on that one physical server. Thereafter Intel-based servers become multi-core, i.e. one server CPU having 2 or 4 processing cores, and the OS could work shift or load balance more easily among the server CPU cores once the OS became fully multi-CPU.
Yet another "workload management" shift came when VMware introduced their first hypervisor in 1999 (2001 for servers), meaning that one workload monitor or janitor, introduced between the server CPU core and the OS, could create virtual machines (i.e. VM) and task switch on the fly between different OS images and builds on the VMs one physical server. The VMs one one server could have different number of CPU cores, memory sized and hard disk volumes associated with them, as well as a mix of operating systems, images and configuration. The VMs could also span CPU cores on many servers, leading to easier ways to do server load balancing, hot-cold or hot-hot fail-over configurations, and, not the least to reduce IT TCO and man-hours, provided a way to migrate and get away from previous 1 application or 1 database equals 1 physical server set-ups.
The introduction of workload and server virtualisation more or less paved the way for today's cloud VM servers and the move away from dedicated servers - per application or per customer install. Without the development and introduction of proper OS and workload hypervisors like VMware, ZEN and KVM it wouldn't be possible to provision and multi-host customer servers and applications in a cost-effective way, and share available CPU core and memory space among many customer workloads.
After a rather lengthy historical background to cloud virtual servers or VMs, what makes up a cloud VM today? It's not a fixed property for sure, as multi-core, hypervised server farms with enough memory can be configured and provisioned in a lot of ways.
Currently, the main service offerings for cloud VMs among cloud providers seems to be:
With this basic overview of cloud VMs, I'll be looking at a the different, or not so different, cloud VM offerings from Amazon AWS, Rackspace, MS Windows Azure, Softlayer and others in an upcoming blog post.
EJ, 22.10.2013
This has been, of course, a regular feature of mainframes for many years ago, and was brought into mainstream server computing accessible for many more with mini machines like DEC VAX-series, UNIX-based workstations and, in the Nordics, Norsk Data Sintran based computers for instance. Looking at the Intel-based server architectures with MS Windows Server OS that overtook these, one had initially 1 CPU (with one CPU core) associated with this one operating system, where the OS could multitask of shift jobs among databases and applications running on that one physical server. Thereafter Intel-based servers become multi-core, i.e. one server CPU having 2 or 4 processing cores, and the OS could work shift or load balance more easily among the server CPU cores once the OS became fully multi-CPU.
Yet another "workload management" shift came when VMware introduced their first hypervisor in 1999 (2001 for servers), meaning that one workload monitor or janitor, introduced between the server CPU core and the OS, could create virtual machines (i.e. VM) and task switch on the fly between different OS images and builds on the VMs one physical server. The VMs one one server could have different number of CPU cores, memory sized and hard disk volumes associated with them, as well as a mix of operating systems, images and configuration. The VMs could also span CPU cores on many servers, leading to easier ways to do server load balancing, hot-cold or hot-hot fail-over configurations, and, not the least to reduce IT TCO and man-hours, provided a way to migrate and get away from previous 1 application or 1 database equals 1 physical server set-ups.
The introduction of workload and server virtualisation more or less paved the way for today's cloud VM servers and the move away from dedicated servers - per application or per customer install. Without the development and introduction of proper OS and workload hypervisors like VMware, ZEN and KVM it wouldn't be possible to provision and multi-host customer servers and applications in a cost-effective way, and share available CPU core and memory space among many customer workloads.
After a rather lengthy historical background to cloud virtual servers or VMs, what makes up a cloud VM today? It's not a fixed property for sure, as multi-core, hypervised server farms with enough memory can be configured and provisioned in a lot of ways.
Currently, the main service offerings for cloud VMs among cloud providers seems to be:
- Fixed size, fixed price VMs: The standard fare of most cloud providers, offering fixed VM configurations with x number of VM cores, typically 2, 4, 8, 12 cores etc, a fixed size of VM RAM memory and disk space at a fixed monthly cost.
- Building on this, some cloud providers also support different ways of doing on the fly VM scaling, i.e. adding more CPU cores, memory or disk space for a certain time if certain traffic or capacity thresholds are being met, or being able to load balance between VMs on different servers.
- Smart servers, i.e. dedicated, single-customer servers with a smallish hypervisor, giving the benefits of hypervised and virtualized workload management, but on dedicated server for increased workload throughput or high-level security environments.
- Cloud VMs can come with different service and availability levels , for instance best-effort (shared, best-effort throughput), reserved, protected or guaranteed VM capacity, 99,5% towards 99,9999% availability
- Increasingly cloud VMs are offered in CPU core pools, where the customer signs up for a pool of CPU cores, for instance 8, 16, 32 or 48 and a given pool of VM RAM and hard disk space, and the customer can configure a number of VM capacities with different CPU cores from this CPU pool. Cloud VMs in this setting are typically billed by utilization hours or minutes per month, and can lead to some very cost-effective server or VM hours per month if managed properly and if one knows the cyclic workload that pool VMs are expected to handle.
With this basic overview of cloud VMs, I'll be looking at a the different, or not so different, cloud VM offerings from Amazon AWS, Rackspace, MS Windows Azure, Softlayer and others in an upcoming blog post.
EJ, 22.10.2013
