Merge branch 'feature/214-add-yaml-docs' into 'theodolite-kotlin'

Add dokumentation for benchmark and execution

See merge request !125

theodolite-quarkus/config/README.md

+## The Benchmark Object
+
+The *benchmark* object defines all static components of an execution of a benchmark with Theodolite.
+An exapmle for a benchmark object is given in [example-benchmark-yaml-resource](example-benchmark-yaml-resource.yaml).
+
+
+A **Benchmark** is a [*standard tool for the competitive evaluation and comparison of competing systems or components according to specific characteristics, such as performance, dependability, or security*](https://doi.org/10.1145/2668930.2688819). In Theodolite, we have [specification-based benchmarks](https://doi.org/10.1145/2668930.2688819), or at least something very close to that. That is, our benchmarks are architectural descriptions---in our case---[of typical use cases of stream processing in microservices](https://doi.org/10.1016/j.bdr.2021.100209) (e.g. our UC1). Hence, we don't really have a piece of software, which represents a benchmark. We only have implementations of benchmarks, e.g. an implementation of UC1 with Kafka Streams. For simplification, we call these *benchmark implementations* simply *benchmarks*.
+
+```yaml
+name: String
+appResource:
+  - String
+  ...
+loadGenResource:
+  - String
+  ...
+resourceTypes:
+  - typeName: String
+    patchers:
+      - type: String
+        resources: String
+        <Patcher Arguments> ...
+      ...
+loadTypes:
+  - typeName: String
+  patchers:
+    - type: String
+      resources: String
+      <Patcher Arguments> ...
+    ...
+kafkaConfig:
+  bootstrapServer: String
+  topics:
+    - name: String
+      numPartitions: UnsignedInt
+      replicationFactor: UnsignedInt
+    - name: String
+      removeOnly: bool
+    ...
+```
+
+The properties have the following definitions:
+
+* **name**: The name of the *benchmark*
+* **appResource**: A list of file names that reference Kubernetes resources that are deployed on the cluster for the system under test (SUT).
+* **loadGenResources**: A list of file names that reference Kubernetes resources that are deployed on the cluster for the load generator.
+* **resourceTypes**: A list of resource types that can be scaled for this *benchmark*. For each resource type the concrete values are defined in the *execution* object. Each resource type has the following structure:
+    * **typeName**: Name of the resource type.
+    * **patchers**: List of [patchers](#Patchers) used to scale this resource type. Each patcher has the following structure:
+        * **type**: Type of the [patcher](#Patchers). The concrete types can be looked up in the list of [patchers](#Patchers). 
+        * **resources**: Specifies the Kubernetes resource to be patched.
+        * **Patcher Arguments**: (Optional) Patcher specific additional arguments.
+* **loadTypes**: A list of load types that can be scaled for this *benchmark*. For each load type the concrete values are defined in the *execution* object. Each load type has the following structure:
+    * **typeName**: Name of the load type.
+    * **patchers**: List of patchers used to scale * **resourceTypes**: A list of resource types that can be scaled for this *benchmark*. For each resource type the concrete values are defined in the *execution* resource object.Each resource type has the following structure:
+    * **typeName**: Name of the resource type.
+    * **patchers**: List of patchers used to scale this resource type. Each patcher has the following structure:
+        * **type**: Type of the Patcher. The concrete types can be looked up in the list of patchers. 
+        * **resources**: Specifies the Kubernetes resource to be patched.
+        * **Patcher Arguments**: (Optional) Patcher specific additional arguments.
+* **kafkaConfig**: Contains the Kafka configuration.
+    * **bootstrapServers**: The bootstrap servers connection string.
+    * **topics**: List of topics to be created for each [experiment](#Experiment). Alternative theodolite offers the possibility to remove certain topics after each experiment.
+        * **name**: The name of the topic.
+        * **numPartitions**: The number of partitions of the topic.
+        * **replicationFactor**: The replication factor of the topic.
+        * **removeOnly**: determines if this topic should only be deleted after each experiement. For removeOnly topics the name can be a RegEx describing the topic.
+    
+
+## The Execution Object
+
+A benchmark can be executed for different SUTs, by different users and multiple times. We call such an execution of a benchmark simply an *execution*. The *execution* object defines all conrete values of an Execution.
+An exapmle for an execution object is given in [example-execution-yaml-resource](example-benchmark-yaml-resource.yaml).
+
+
+```yaml
+name: String
+benchmark: String
+load:
+  loadType: String
+  loadValues:
+    - UnsignedInt
+    ...
+resources:
+  resourceType: String
+  resourceValues:
+    - UnsignedInt
+    ...
+slos:
+  - sloType: String
+    threshold: UnsignedInt
+    prometheusUrl: String
+    externalSloUrl: String
+    offset: SignedInt
+    warmup: UnsignedInt
+  ...
+executions:
+  strategy: "LinearSearch" or "BinarySearch"
+  duration: UnsignedInt
+  repetition: UnsignedInt
+  restrictions:
+    - "LowerBound"
+    ...
+configurationOverrides:
+  - patcher:
+      type: String
+      resource: String
+      <Patcher Arguments> ...
+  ...
+```
+
+The properties have the following definitions:
+
+* **name**: The name of the *execution*
+* **benchmark**: The name of the *benchmark* this *execution* is referring to.
+* **load**: Specifies the load values that are benchmarked.
+  * **loadType**: The type of the load. It must match one of the load types specified in the referenced *benchmark*.
+  * **loadValues**: List of load values for the specified load type.
+* **resources**: Specifies the scaling resource that is benchmarked.
+  * **resourceType**: The type of the resource. It must match one of the resource types specified in the referenced *benchmark*.
+  * **resourceValues**: List of resource values for the specified resource type.
+* **slos**: List of the Service Level Objective (SLO) for this *execution*. Each SLO has the following fields:
+  * **sloType**: The type of the SLO. It must match 'lag trend'.
+  * **threshold**: The threshold the SUT should meet for a sucessful experiment.
+  * **prometheusUrl**: Connection string for promehteus.
+  * **externalSloUrl**: Connection string for a external slo analysis.
+  * **offset**: Hours by which the start and end timestamp will be shifted (for different timezones).
+  * **warmup**: Seconds of time that are ignored in the analysis.
+* **executions**: Defines the overall parameter for the execution.
+  * **strategy**: Defines the used strategy for the execution: either 'LinearSearch' or 'BinarySearch'
+  * **duration**: Defines the duration of each [experiment](#Experiment) in seconds.
+  * **repetition**: Unused.
+  * **restrictions**: List of restriction strategys used to delimit the search space.
+    **- LowerBound**: Currently only supported *restriction strategy*.
+* **configurationOverrides**: List of patchers that are used to override existing configurations.
+  * **patcher**: Patcher used to patch a resource. Each patcher has the following structure:
+        * **type**: Type of the Patcher. The concrete types can be looked up in the list of patchers. 
+        * **resources**: Specifies the Kubernetes resource to be patched.
+        * **Patcher Arguments**: (Optional) Patcher specific additional arguments.
+
+## Patchers
+
+* **ReplicaPatcher**: Allows to modify the number of Replicas for a kubernetes deployment.
+  * **type**: "ReplicaPatcher"
+  * **resource**: "uc1-kstreams-deployment.yaml"
+
+* **NumSensorsLoadGeneratorReplicaPatcher**: Allows to scale the nummer of load generators. Scales arcording to the following formular: (value + 15_000 - 1) / 15_000
+  * **type**: "NumSensorsLoadGeneratorReplicaPatcher"
+  * **resource**: "uc1-load-generator-deployment.yaml"
+
+* **NumNestedGroupsLoadGeneratorReplicaPatcher**: Allows to scale the nummer of load generators. Scales arcording to the following formular: (4^(value) + 15_000 -1) /15_000
+  * **type**: "NumNestedGroupsLoadGeneratorReplicaPatcher"
+  * **resource**: "uc1-load-generator-deployment.yaml"
+
+* **ReplicaPatcher**: Allows to modify the number of Replicas for a kubernetes deployment.
+  * **type**: "ReplicaPatcher"
+  * **resource**: "uc1-kstreams-deployment.yaml"
+
+* **EnvVarPatcher**: Allows to modify the value of an environment variable for a container in a kubernetes deployment. 
+  * **type**: "EnvVarPatcher"
+  * **resource**: "uc1-load-generator-deployment.yaml"
+  * **container**: "workload-generator"
+  * **variableName**: "NUM_SENSORS"
+
+* **NodeSelectorPatcher**: Changes the node selection field in kubernetes resources.
+  * **type**: "NodeSelectorPatcher"
+  * **resource**: "uc1-load-generator-deployment.yaml"
+  * **variableName**: "env"
+  * **value**: "prod"
+
+* **ResourceLimitPatcher**: Changes the resource limit for a kubernetes resource.
+  * **resource**: "uc1-kstreams-deployment.yaml"
+  * **container**: "uc-application"
+  * **variableName**: "cpu" or "memory"
+  * **value**:"1000m" or "2Gi"
+  
+* **SchedulerNamePatcher**: Changes the sheduler for kubernetes resources.
+  * **type**: "SchedulerNamePatcher"
+  * **resource**: "uc1-kstreams-deployment.yaml"
+  * **value**: "random-scheduler"
+
+* **ImagePatcher**: Changes the image of a kubernetes resource. Currently not fully implemented.
+  * **type**: "ImagePatcher"
+  * **resource**: "uc1-kstreams-deployment.yaml"
+  * **container**: "uc-application"
+  * **value**: "dockerhubrepo/imagename"
+
+
+
+## Experiment
+According to [our benchmarking method](https://doi.org/10.1016/j.bdr.2021.100209), the execution of a benchmark requires performing multiple **Experiments**. I think what is actually done within/during an experiment is another level of detail. (But just for the sake of completeness: In an experiment, the benchmark implementation is deployed, load is generated according to the benchmark specification, some SLOs are monitored continuously, etc.)
+
+
+