io_hog.md

I/O Hog

This scenario is based on the arcaflow arcaflow-plugin-stressng plugin. The purpose of this scenario is to create disk pressure on a particular node of the Kubernetes/OpenShift cluster for a time span. The scenario allows to attach a node path to the pod as a hostPath volume. To enable this plugin add the pointer to the scenario input file scenarios/arcaflow/io-hog/input.yaml as described in the Usage section. This scenario takes a list of objects named input_list with the following properties:

• kubeconfig : string the kubeconfig needed by the deployer to deploy the sysbench plugin in the target cluster
• namespace : string the namespace where the scenario container will be deployed Note: this parameter will be automatically filled by kraken if the kubeconfig_path property is correctly set
• node_selector : key-value map the node label that will be used as nodeSelector by the pod to target a specific cluster node
• duration : string stop stress test after N seconds. One can also specify the units of time in seconds, minutes, hours, days or years with the suffix s, m, h, d or y.
• target_pod_folder : string the path in the pod where the volume is mounted
• target_pod_volume : object the hostPath volume definition in the Kubernetes/OpenShift format, that will be attached to the pod as a volume
• io_write_bytes : string writes N bytes for each hdd process. The size can be expressed as % of free space on the file system or in units of Bytes, KBytes, MBytes and GBytes using the suffix b, k, m or g
• io_block_size : string size of each write in bytes. Size can be from 1 byte to 4m.

To perform several load tests in the same run simultaneously (eg. stress two or more nodes in the same run) add another item to the input_list with the same properties (and eventually different values eg. different node_selectors to schedule the pod on different nodes). To reduce (or increase) the parallelism change the value parallelism in workload.yaml file