From 5154d94a10d1e55063b7fc882b2b35e6ee19fe4c Mon Sep 17 00:00:00 2001 From: Henning Jacobs Date: Sun, 12 Feb 2017 12:42:30 +0100 Subject: [PATCH] #11 change wording in README for allocatable --- README.rst | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/README.rst b/README.rst index 5ec077b..20255a5 100644 --- a/README.rst +++ b/README.rst @@ -21,6 +21,8 @@ Goals: * respect Availability Zones, i.e. make sure that all AZs provide enough capacity * be deterministic and predictable, i.e. the ``DesiredCapacity`` is only calculated based on the current cluster state * scale down slowly to mitigate service disruptions, i.e. at most one node at a time +* support "elastic" workloads like daily up/down scaling +* support AWS Spot Fleet (not yet implemented) * require a minimum amount of configuration (preferably none) * keep it simple @@ -32,6 +34,13 @@ This hack was created as a proof of concept and born out of frustration with the * it requires unnecessary configuration * the code is quite complex +Disclaimer +========== + +** Use at your own risk! ** +This autoscaler was only tested with Kubernetes version 1.5.2. +There is no guarantee that it works in previous Kubernetes versions. + How it works ============ @@ -48,7 +57,7 @@ The ``autoscale`` function performs the following task: * iterate through every ASG/AZ combination * use the calculated resource usage (sum of resource requests) and add the resource requests of any unassigned pods (pods not scheduled on any node yet) * apply the configured buffer values (10% extra for CPU and memory by default) - * find the capacity of the weakest node + * find the `allocatable capacity`_ of the weakest node * calculate the number of required nodes by adding up the capacity of the weakest node until the sum is greater than or equal to requested+buffer for both CPU and memory * sum up the number of required nodes from all AZ for the ASG @@ -99,3 +108,4 @@ The following command line options are supported: .. _"official" cluster-autoscaler: https://github.com/kubernetes/contrib/tree/master/cluster-autoscaler +.. _allocatable capacity: https://github.com/kubernetes/community/blob/master/contributors/design-proposals/node-allocatable.md