Add automaxprocs

Signed-off-by: Alexander Tunik <2braven@gmail.com>

cmd/thanos/main.go

@@ -35,6 +35,7 @@ import (
 	"github.com/thanos-io/thanos/pkg/runutil"
 	"github.com/thanos-io/thanos/pkg/tracing"
 	"github.com/thanos-io/thanos/pkg/tracing/client"
+	"go.uber.org/automaxprocs/maxprocs"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
@@ -115,6 +116,18 @@ func main() {
 		logger = log.With(logger, "ts", log.DefaultTimestampUTC, "caller", log.DefaultCaller)
 	}
 
+	loggerAdapter := func(template string, args ...interface{}) {
+		level.Debug(logger).Log("msg", fmt.Sprintf(template, args))
+	}
+
+	// Running in container with limits but with empty/wrong value of GOMAXPROCS env var could lead to throttling by cpu
+	// maxprocs will automate adjustment by using cgroups info about cpu limit if it set as value for runtime.GOMAXPROCS
+	undo, err := maxprocs.Set(maxprocs.Logger(loggerAdapter))
+	defer undo()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, errors.Wrapf(err, "failed to set GOMAXPROCS: %v", err))
+	}
+
 	metrics := prometheus.NewRegistry()
 	metrics.MustRegister(
 		version.NewCollector("thanos"),

go.mod

@@ -39,6 +39,7 @@ require (
 	github.com/uber/jaeger-client-go v2.16.0+incompatible
 	github.com/uber/jaeger-lib v2.0.0+incompatible
 	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/automaxprocs v1.2.0
 	golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58
 	golang.org/x/text v0.3.2

go.sum

@@ -410,6 +410,7 @@ go.opencensus.io v0.22.0 h1:C9hSCOW830chIVkdja34wa6Ky+IzWllkUinR+BtRZd4=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
+go.uber.org/automaxprocs v1.2.0/go.mod h1:YfO3fm683kQpzETxlTGZhGIVmXAhaw3gxeBADbpZtnU=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181025213731-e84da0312774/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181029021203-45a5f77698d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=