Chapter 17. Creating a performance profile

Procedure

1. Optional: Verify that a matching machine config pool exists with a label:

   $ oc describe mcp/worker-rt

   Example output

   Name:         worker-rt
   Namespace:
   Labels:       machineconfiguration.openshift.io/role=worker-rt

2. If a matching label does not exist add a label for a machine config pool (MCP) that matches with the MCP name:

   $ oc label mcp <mcp_name> <mcp_name>=""

3. Navigate to the directory where you want to store the must-gather data.

4. Run must-gather on your cluster:

   $ oc adm must-gather --image=<PAO_image> --dest-dir=<dir>

   Note

   The must-gather command must be run with the performance-addon-operator-must-gather image. The output can optionally be compressed. Compressed output is required if you are running the Performance Profile Creator wrapper script.

   Example

   $ oc adm must-gather --image=registry.redhat.io/openshift4/performance-addon-operator-must-gather-rhel8:v4.10 --dest-dir=must-gather

5. Create a compressed file from the must-gather directory:

   $ tar cvaf must-gather.tar.gz must-gather/

Procedure

1. Check the machine config pool:

   $ oc get mcp

   Example output

   NAME         CONFIG                                                 UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
   master       rendered-master-acd1358917e9f98cbdb599aea622d78b       True      False      False      3              3                   3                     0                      22h
   worker-cnf   rendered-worker-cnf-1d871ac76e1951d32b2fe92369879826   False     True       False      2              1                   1                     0                      22h

2. Use Podman to authenticate to registry.redhat.io:

   $ podman login registry.redhat.io

   Username: <username>
   Password: <password>

3. Optional: Display help for the PPC tool:

   $ podman run --entrypoint performance-profile-creator registry.redhat.io/openshift4/performance-addon-rhel8-operator:v4.10 -h

   Example output

   A tool that automates creation of Performance Profiles
   
   Usage:
     performance-profile-creator [flags]
   
   Flags:
         --disable-ht                        Disable Hyperthreading
     -h, --help                              help for performance-profile-creator
         --info string                       Show cluster information; requires --must-gather-dir-path, ignore the other arguments. [Valid values: log, json] (default "log")
         --mcp-name string                   MCP name corresponding to the target machines (required)
         --must-gather-dir-path string       Must gather directory path (default "must-gather")
         --power-consumption-mode string     The power consumption mode.  [Valid values: default, low-latency, ultra-low-latency] (default "default")
         --profile-name string               Name of the performance profile to be created (default "performance")
         --reserved-cpu-count int            Number of reserved CPUs (required)
         --rt-kernel                         Enable Real Time Kernel (required)
         --split-reserved-cpus-across-numa   Split the Reserved CPUs across NUMA nodes
         --topology-manager-policy string    Kubelet Topology Manager Policy of the performance profile to be created. [Valid values: single-numa-node, best-effort, restricted] (default "restricted")
         --user-level-networking             Run with User level Networking(DPDK) enabled

4. Run the Performance Profile Creator tool in discovery mode:

   Note

   Discovery mode inspects your cluster using the output from must-gather. The output produced includes information on:

   • The NUMA cell partitioning with the allocated CPU ids
   • Whether hyperthreading is enabled

   Using this information you can set appropriate values for some of the arguments supplied to the Performance Profile Creator tool.

   $ podman run --entrypoint performance-profile-creator -v /must-gather:/must-gather:z registry.redhat.io/openshift4/performance-addon-rhel8-operator:v4.10 --info log --must-gather-dir-path /must-gather

   Note

   This command uses the performance profile creator as a new entry point to podman. It maps the must-gather data for the host into the container image and invokes the required user-supplied profile arguments to produce the my-performance-profile.yaml file.

   The -v option can be the path to either:

   • The must-gather output directory
   • An existing directory containing the must-gather decompressed tarball

   The info option requires a value which specifies the output format. Possible values are log and JSON. The JSON format is reserved for debugging.

5. Run podman:

   $ podman run --entrypoint performance-profile-creator -v /must-gather:/must-gather:z registry.redhat.io/openshift4/performance-addon-rhel8-operator:v4.10 --mcp-name=worker-cnf --reserved-cpu-count=20 --rt-kernel=true --split-reserved-cpus-across-numa=false --topology-manager-policy=single-numa-node --must-gather-dir-path /must-gather  --power-consumption-mode=ultra-low-latency > my-performance-profile.yaml

   Note

   The Performance Profile Creator arguments are shown in the Performance Profile Creator arguments table. The following arguments are required:

   • reserved-cpu-count
   • mcp-name
   • rt-kernel

   The mcp-name argument in this example is set to worker-cnf based on the output of the command oc get mcp. For single-node OpenShift use --mcp-name=master.

6. Review the created YAML file:

   $ cat my-performance-profile.yaml

   Example output

   apiVersion: performance.openshift.io/v2
   kind: PerformanceProfile
   metadata:
     name: performance
   spec:
     additionalKernelArgs:
     - nmi_watchdog=0
     - audit=0
     - mce=off
     - processor.max_cstate=1
     - intel_idle.max_cstate=0
     - idle=poll
     cpu:
       isolated: 1,3,5,7,9,11,13,15,17,19-39,41,43,45,47,49,51,53,55,57,59-79
       reserved: 0,2,4,6,8,10,12,14,16,18,40,42,44,46,48,50,52,54,56,58
     nodeSelector:
       node-role.kubernetes.io/worker-cnf: ""
     numa:
       topologyPolicy: single-numa-node
     realTimeKernel:
       enabled: true

7. Apply the generated profile:

   Note

   Install the Performance Addon Operator before applying the profile.

   $ oc apply -f my-performance-profile.yaml

Procedure

1. Create a file on your local machine named, for example, run-perf-profile-creator.sh:

   $ vi run-perf-profile-creator.sh

2. Paste the following code into the file:

   #!/bin/bash
   
   readonly CONTAINER_RUNTIME=${CONTAINER_RUNTIME:-podman}
   readonly CURRENT_SCRIPT=$(basename "$0")
   readonly CMD="${CONTAINER_RUNTIME} run --entrypoint performance-profile-creator"
   readonly IMG_EXISTS_CMD="${CONTAINER_RUNTIME} image exists"
   readonly IMG_PULL_CMD="${CONTAINER_RUNTIME} image pull"
   readonly MUST_GATHER_VOL="/must-gather"
   
   PAO_IMG="registry.redhat.io/openshift4/performance-addon-rhel8-operator:v4.10"
   MG_TARBALL=""
   DATA_DIR=""
   
   usage() {
     print "Wrapper usage:"
     print "  ${CURRENT_SCRIPT} [-h] [-p image][-t path] -- [performance-profile-creator flags]"
     print ""
     print "Options:"
     print "   -h                 help for ${CURRENT_SCRIPT}"
     print "   -p                 Performance Addon Operator image"
     print "   -t                 path to a must-gather tarball"
   
     ${IMG_EXISTS_CMD} "${PAO_IMG}" && ${CMD} "${PAO_IMG}" -h
   }
   
   function cleanup {
     [ -d "${DATA_DIR}" ] && rm -rf "${DATA_DIR}"
   }
   trap cleanup EXIT
   
   exit_error() {
     print "error: $*"
     usage
     exit 1
   }
   
   print() {
     echo  "$*" >&2
   }
   
   check_requirements() {
     ${IMG_EXISTS_CMD} "${PAO_IMG}" || ${IMG_PULL_CMD} "${PAO_IMG}" || \
         exit_error "Performance Addon Operator image not found"
   
     [ -n "${MG_TARBALL}" ] || exit_error "Must-gather tarball file path is mandatory"
     [ -f "${MG_TARBALL}" ] || exit_error "Must-gather tarball file not found"
   
     DATA_DIR=$(mktemp -d -t "${CURRENT_SCRIPT}XXXX") || exit_error "Cannot create the data directory"
     tar -zxf "${MG_TARBALL}" --directory "${DATA_DIR}" || exit_error "Cannot decompress the must-gather tarball"
     chmod a+rx "${DATA_DIR}"
   
     return 0
   }
   
   main() {
     while getopts ':hp:t:' OPT; do
       case "${OPT}" in
         h)
           usage
           exit 0
           ;;
         p)
           PAO_IMG="${OPTARG}"
           ;;
         t)
           MG_TARBALL="${OPTARG}"
           ;;
         ?)
           exit_error "invalid argument: ${OPTARG}"
           ;;
       esac
     done
     shift $((OPTIND - 1))
   
     check_requirements || exit 1
   
     ${CMD} -v "${DATA_DIR}:${MUST_GATHER_VOL}:z" "${PAO_IMG}" "$@" --must-gather-dir-path "${MUST_GATHER_VOL}"
     echo "" 1>&2
   }
   
   main "$@"

3. Add execute permissions for everyone on this script:

   $ chmod a+x run-perf-profile-creator.sh

4. Optional: Display the run-perf-profile-creator.sh command usage:

   $ ./run-perf-profile-creator.sh -h

   Expected output

   Wrapper usage:
     run-perf-profile-creator.sh [-h] [-p image][-t path] -- [performance-profile-creator flags]
   
   Options:
      -h                 help for run-perf-profile-creator.sh
      -p                 Performance Addon Operator image 1
      -t                 path to a must-gather tarball 2
   
   A tool that automates creation of Performance Profiles
   
      Usage:
        performance-profile-creator [flags]
   
      Flags:
            --disable-ht                        Disable Hyperthreading
        -h, --help                              help for performance-profile-creator
            --info string                       Show cluster information; requires --must-gather-dir-path, ignore the other arguments. [Valid values: log, json] (default "log")
            --mcp-name string                   MCP name corresponding to the target machines (required)
            --must-gather-dir-path string       Must gather directory path (default "must-gather")
            --power-consumption-mode string     The power consumption mode.  [Valid values: default, low-latency, ultra-low-latency] (default "default")
            --profile-name string               Name of the performance profile to be created (default "performance")
            --reserved-cpu-count int            Number of reserved CPUs (required)
            --rt-kernel                         Enable Real Time Kernel (required)
            --split-reserved-cpus-across-numa   Split the Reserved CPUs across NUMA nodes
            --topology-manager-policy string    Kubelet Topology Manager Policy of the performance profile to be created. [Valid values: single-numa-node, best-effort, restricted] (default "restricted")
            --user-level-networking             Run with User level Networking(DPDK) enabled

   Note

   There two types of arguments:

   • Wrapper arguments namely -h, -p and -t
   • PPC arguments

   1

   Optional: Specify the Performance Addon Operator image. If not set, the default upstream image is used: registry.redhat.io/openshift4/performance-addon-rhel8-operator:v4.10.

   2

   -t is a required wrapper script argument and specifies the path to a must-gather tarball.

5. Run the performance profile creator tool in discovery mode:

   Note

   Discovery mode inspects your cluster using the output from must-gather. The output produced includes information on:

   • The NUMA cell partitioning with the allocated CPU IDs
   • Whether hyperthreading is enabled

   Using this information you can set appropriate values for some of the arguments supplied to the Performance Profile Creator tool.

   $ ./run-perf-profile-creator.sh -t /must-gather/must-gather.tar.gz -- --info=log

   Note

   The info option requires a value which specifies the output format. Possible values are log and JSON. The JSON format is reserved for debugging.

6. Check the machine config pool:

   $ oc get mcp

   Example output

   NAME         CONFIG                                                 UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
   master       rendered-master-acd1358917e9f98cbdb599aea622d78b       True      False      False      3              3                   3                     0                      22h
   worker-cnf   rendered-worker-cnf-1d871ac76e1951d32b2fe92369879826   False     True       False      2              1                   1                     0                      22h

7. Create a performance profile:

   $ ./run-perf-profile-creator.sh -t /must-gather/must-gather.tar.gz -- --mcp-name=worker-cnf --reserved-cpu-count=2 --rt-kernel=true > my-performance-profile.yaml

   Note

   The Performance Profile Creator arguments are shown in the Performance Profile Creator arguments table. The following arguments are required:

   • reserved-cpu-count
   • mcp-name
   • rt-kernel

   The mcp-name argument in this example is set to worker-cnf based on the output of the command oc get mcp. For single-node OpenShift use --mcp-name=master.

8. Review the created YAML file:

   $ cat my-performance-profile.yaml

   Example output

   apiVersion: performance.openshift.io/v2
   kind: PerformanceProfile
   metadata:
     name: performance
   spec:
     cpu:
       isolated: 1-39,41-79
       reserved: 0,40
     nodeSelector:
       node-role.kubernetes.io/worker-cnf: ""
     numa:
       topologyPolicy: restricted
     realTimeKernel:
       enabled: false

9. Apply the generated profile:

   Note

   Install the Performance Addon Operator before applying the profile.

   $ oc apply -f my-performance-profile.yaml