Method handleProfiling

rest/api.go:556–614

ADMIN API to turn Go CPU profiling on/off

()

// ADMIN API to turn Go CPU profiling on/off
func (h *handler) handleProfiling() (err error) {
	profileName := h.PathVar("profilename")
	isCPUProfile := profileName == ""

	var params struct {
		File string `json:"file"`
	}
	body, err := h.readBody()
	if err != nil {
		return err
	}
	if len(body) > 0 {
		if err = base.JSONUnmarshal(body, &params); err != nil {
			return err
		}
	}

	// Handle no file
	if params.File == "" {
		if isCPUProfile {
			base.InfofCtx(h.ctx(), base.KeyAll, "... ending CPU profile")
			pprof.StopCPUProfile()
			filename := h.server.CloseCpuPprofFile(h.ctx())
			base.Audit(h.ctx(), base.AuditIDSyncGatewayProfiling, base.AuditFields{base.AuditFieldPprofProfileType: "cpu", base.AuditFieldFileName: filename})
			return nil
		}
		return base.HTTPErrorf(http.StatusBadRequest, "Missing JSON 'file' parameter")
	}

	f, err := os.Create(params.File)
	if err != nil {
		return err
	}

	if isCPUProfile {
		base.InfofCtx(h.ctx(), base.KeyAll, "Starting CPU profile to %s ...", base.UD(params.File))
		base.Audit(h.ctx(), base.AuditIDSyncGatewayProfiling, base.AuditFields{base.AuditFieldPprofProfileType: "cpu (start)", base.AuditFieldFileName: params.File})
		if err = pprof.StartCPUProfile(f); err != nil {
			if fileError := os.Remove(params.File); fileError != nil {
				base.InfofCtx(h.ctx(), base.KeyAll, "Error removing file: %s", base.UD(params.File))
			}
			return err
		}
		h.server.SetCpuPprofFile(f)
		return err
	} else if profile := pprof.Lookup(profileName); profile != nil {
		base.InfofCtx(h.ctx(), base.KeyAll, "Writing %q profile to %s ...", profileName, base.UD(params.File))
		err = profile.WriteTo(f, 0)
		base.Audit(h.ctx(), base.AuditIDSyncGatewayProfiling, base.AuditFields{base.AuditFieldPprofProfileType: profileName, base.AuditFieldFileName: params.File})
	} else {
		err = base.HTTPErrorf(http.StatusNotFound, "No such profile %q", profileName)
	}

	if fileCloseError := f.Close(); fileCloseError != nil {
		base.WarnfCtx(h.ctx(), "Error closing profile file: %v", fileCloseError)
	}

	return err