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.)

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

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

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

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

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

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