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The Mesos system has two basic methods to describe the slaves that comprise a cluster. One of these is managed by the Mesos master, the other is simply passed onwards to the frameworks using the cluster.
The attributes are simply key value string pairs that Mesos passes along when it sends offers to frameworks.
attributes : attribute ( ";" attribute )* attribute : labelString ":" ( labelString | "," )+
The Mesos system can manage 3 different types of resources: scalars, ranges, and sets. These are used to represent the different resources that a Mesos slave has to offer. For example, a scalar resource type could be used to represent the amount of memory on a slave. Each resource is identified by a key string.
resources : resource ( ";" resource )* resource : key ":" ( scalar | range | set ) key : labelString ( "(" resourceRole ")" )? scalar : floatValue range : "[" rangeValue ( "," rangeValue )* "]" rangeValue : scalar "-" scalar set : "{" labelString ( "," labelString )* "}" resourceRole : labelString | "*" labelString : [a-zA-Z0-9_/.-] floatValue : ( intValue ( "." intValue )? ) | ... intValue : [0-9]+
The Mesos master has a few resources that it pre-defines in how it handles them. At the current time, this list consist of:
cpu
mem
disk
ports
In particular, a slave without cpu
and mem
resources will never have its resources advertised to any frameworks. Also, the Master's user interface interprets the scalars in mem
and disk
in terms of MB
. IE: the value 15000
is displayed as 14.65GB
.
Here are some examples for configuring the Mesos slaves.
--resources='cpu:24;mem:24576;disk:409600;ports:[21000-24000];bugs:{a,b,c}' --attributes='rack:abc;zone:west;os:centos5,full'
In this case, we have three different types of resources, scalars, a range, and a set. They are called cpu
, mem
, disk
, and the range type is ports
.
cpu
, with the value 24
mem
, with the value 24576
disk
, with the value 409600
ports
, with values 21000
through 24000
(inclusive)bugs
, with the values a
, b
and c
In the case of attributes, we end up with three attributes:
rack
with value abc
zone
with value west
os
with value centos5,full