github.com/anth0d/nomad@v0.0.0-20221214183521-ae3a0a2cad06/client/fingerprint/cpu.go (about)

     1  package fingerprint
     2  
     3  import (
     4  	"fmt"
     5  	"strconv"
     6  
     7  	"github.com/hashicorp/nomad/lib/cpuset"
     8  
     9  	log "github.com/hashicorp/go-hclog"
    10  	"github.com/hashicorp/nomad/helper/stats"
    11  	"github.com/hashicorp/nomad/nomad/structs"
    12  )
    13  
    14  const (
    15  	// defaultCPUTicks is the default amount of CPU resources assumed to be
    16  	// available if the CPU performance data is unable to be detected. This is
    17  	// common on EC2 instances, where the env_aws fingerprinter will follow up,
    18  	// setting an accurate value.
    19  	defaultCPUTicks = 1000 // 1 core * 1 GHz
    20  )
    21  
    22  // CPUFingerprint is used to fingerprint the CPU
    23  type CPUFingerprint struct {
    24  	StaticFingerprinter
    25  	logger log.Logger
    26  }
    27  
    28  // NewCPUFingerprint is used to create a CPU fingerprint
    29  func NewCPUFingerprint(logger log.Logger) Fingerprint {
    30  	f := &CPUFingerprint{logger: logger.Named("cpu")}
    31  	return f
    32  }
    33  
    34  func (f *CPUFingerprint) Fingerprint(req *FingerprintRequest, resp *FingerprintResponse) error {
    35  	cfg := req.Config
    36  	setResourcesCPU := func(totalCompute int, totalCores uint16, reservableCores []uint16) {
    37  		// COMPAT(0.10): Remove in 0.10
    38  		resp.Resources = &structs.Resources{
    39  			CPU: totalCompute,
    40  		}
    41  
    42  		resp.NodeResources = &structs.NodeResources{
    43  			Cpu: structs.NodeCpuResources{
    44  				CpuShares:          int64(totalCompute),
    45  				TotalCpuCores:      totalCores,
    46  				ReservableCpuCores: reservableCores,
    47  			},
    48  		}
    49  	}
    50  
    51  	if err := stats.Init(); err != nil {
    52  		f.logger.Warn("failed initializing stats collector", "error", err)
    53  	}
    54  
    55  	if modelName := stats.CPUModelName(); modelName != "" {
    56  		resp.AddAttribute("cpu.modelname", modelName)
    57  	}
    58  
    59  	if mhz := stats.CPUMHzPerCore(); mhz > 0 {
    60  		resp.AddAttribute("cpu.frequency", fmt.Sprintf("%.0f", mhz))
    61  		f.logger.Debug("detected cpu frequency", "MHz", log.Fmt("%.0f", mhz))
    62  	}
    63  
    64  	var numCores int
    65  	if numCores = stats.CPUNumCores(); numCores > 0 {
    66  		resp.AddAttribute("cpu.numcores", strconv.Itoa(numCores))
    67  		f.logger.Debug("detected core count", "cores", numCores)
    68  	}
    69  
    70  	var reservableCores []uint16
    71  	if req.Config.ReservableCores != nil {
    72  		reservableCores = req.Config.ReservableCores
    73  		f.logger.Debug("reservable cores set by config", "cpuset", reservableCores)
    74  	} else {
    75  		if cores, err := f.deriveReservableCores(req); err != nil {
    76  			f.logger.Warn("failed to detect set of reservable cores", "error", err)
    77  		} else {
    78  			if req.Node.ReservedResources != nil {
    79  				reservableCores = cpuset.New(cores...).Difference(cpuset.New(req.Node.ReservedResources.Cpu.ReservedCpuCores...)).ToSlice()
    80  			}
    81  			f.logger.Debug("detected reservable cores", "cpuset", reservableCores)
    82  		}
    83  	}
    84  	resp.AddAttribute("cpu.reservablecores", strconv.Itoa(len(reservableCores)))
    85  
    86  	tt := int(stats.TotalTicksAvailable())
    87  	if cfg.CpuCompute > 0 {
    88  		f.logger.Debug("using user specified cpu compute", "cpu_compute", cfg.CpuCompute)
    89  		tt = cfg.CpuCompute
    90  	}
    91  
    92  	// If we cannot detect the cpu total compute, fallback to a very low default
    93  	// value and log a message about configuring cpu_total_compute. This happens
    94  	// on Graviton instances where CPU information is unavailable. In that case,
    95  	// the env_aws fingerprinter updates the value with correct information.
    96  	if tt == 0 {
    97  		f.logger.Info("fallback to default cpu total compute, set client config option cpu_total_compute to override")
    98  		tt = defaultCPUTicks
    99  	}
   100  
   101  	resp.AddAttribute("cpu.totalcompute", fmt.Sprintf("%d", tt))
   102  	setResourcesCPU(tt, uint16(numCores), reservableCores)
   103  	resp.Detected = true
   104  
   105  	return nil
   106  }