1. Cluster – defn. TBD Derek:
Homogenous set of nodes; in TOSCA that is a single node template.
- Matt said this can also be viewed as a stack
- - Derek can be represented as a single “container” template (which Compute is a node template for a “stack” container.
- Can be treated symmetrically
- tier lifecycles are independent of each other
- therefore no dependencies on each other (from a mgmt.. perspective)
Matt: perhaps use ELK for starters, to work thru?
Matt: Cluster conveys “mgmt” to the provider, whatever is “inside” (i.e., members) can be managed via the Cluster (node) using the capabilities (e.g., LoadBalancer, Router, etc.)

2. Single Compute/Container
Eg. single Docker container, scaling, load balancing (, placement)

3. tosca.nodes.Container.App.Docker
Single Docker Container (Compute only) – Simple Alternative Container-Only policies, no Cluster aggregate (still valid)
Container Manager MUST infer capabilities for:
LoadBalancer: Needed to distribute “load” as measured by platform provider
Router: needs to be created by provider to route between
instances
Scaling
Policy
LoadBalancing
Policy
my_docker_lambda_fx
HTTP RESTful endpoint, single entry
tosca.nodes.Container.App.Docker
properties:
...
capabilities:
- Endpoint
1..N
Could be autonomous containers?
Any Cloud platform MUST have some defact “Container manager”
(cant have more than 1 of the container without some function to manage resources) 3 3

4. tosca.nodes.Container.App.Docker
Single Docker Container (Compute only) – Using Cluster Agg. Construct (assumption policies override those supplied at Container-level)
Scaling
Policy
Container Manager has explicit Capabilities declared:
LoadBalancer: Needed to distribute “load” as measured by platform provider
Router: needs to be created by provider to route between
instances
landa_fx_cluster
Cluster
type: tosca.groups.Root
members: [my_docker_lambda_fx ]
capabilities:
LoadBalancing:
Router:
...
LoadBalancing
Policy
HTTP RESTful endpoint, single entry
Scaling
Policy X
my_docker_lambda_fx
tosca.nodes.Container.App.Docker
1..N
properties:
...
capabilities:
- Endpoint
LoadBalancing
Policy X 4 4

5. Two Docker Container (Compute only) – Using Cluster
landa_fx_cluster
Cluster
type: tosca.groups.Root
members: [
my_docker_lambda_fx1,
my_docker_lambda_fx2 ]
capabilities:
LoadBalancing:
Router:
...
Scaling
Policy
LoadBalancing
Policy
HTTP RESTful endpoint, single entry
my_docker_lambda_fx2
my_docker_lambda_fx1
tosca.nodes.Container.App.Docker
tosca.nodes.Container.App.Docker
1..N
1..N
properties:
...
capabilities:
- Endpoint
properties:
...
capabilities:
- Endpoint 5 5

6. ELK Cluster (Tier? Stack?)
db_cluster
Cluster
type: tosca.groups.Root
members: [ mongo ]
capabilities:
LoadBalancing:
Router:
...
my_docker_kibana
my_docker_elasticsearch
my_docker_logstash
tosca.nodes.Container.App
tosca.nodes.Container.App
tosca.nodes.Container.App
type: tosca.groups.Root
properties:
...
type: tosca.groups.Root
properties:
role:
...
type: tosca.groups.Root
properties:
... 6 6

7. Expressing Cluster Semantics
Composite lifecycle
Node external policy
Binary constraint for ration of a pair of node instances
Placement_zones: R1,R2, R3
Node internal policy
Composite lifecycle: deploy, undeploy, start, stop, update
Placement_weights:
R1=2, R2=2, R3=1
Scaling_strategy: auto 2:1
Scaling_ratio: 2:1
Max(A) = 4000
Placement_weights:
R1=2, R2=2, R3=3
Scaling_limit: 3000
Scaling_limit(A): 1000 B
4:1
Binary constraint mapping connectivity from source to target
Ways to express:
Topological policy applied to the relationship from A to B)
Requirement in the relation
1:2 A
A.1 -> B.1, B2
A.2 -> B.3, B.4 … D
1:3 C
6:1
Scaling (limit): 10000
Min instances: 24 …
Scaling_limit: 4000
Min instances: 8
Unary constraint on node
Constraints built-in to the nodes should be inside the nodes but can’t fit in this diagram