Merge pull request #4418 from simonpasquier/log-vm-limits

prometheus: log virtual memory limits

cmd/prometheus/limits_default.go

@@ -0,0 +1,48 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"syscall"
+)
+
+// syscall.RLIM_INFINITY is a constant and its default type is int.
+// It needs to be converted to an int64 variable to be compared with uint64 values.
+// See https://golang.org/ref/spec#Conversions
+var unlimited int64 = syscall.RLIM_INFINITY
+
+func limitToString(v uint64, unit string) string {
+	if v == uint64(unlimited) {
+		return "unlimited"
+	}
+	return fmt.Sprintf("%d%s", v, unit)
+}
+
+func getLimits(resource int, unit string) string {
+	rlimit := syscall.Rlimit{}
+	err := syscall.Getrlimit(resource, &rlimit)
+	if err != nil {
+		log.Fatal("Error!")
+	}
+	return fmt.Sprintf("(soft=%s, hard=%s)", limitToString(uint64(rlimit.Cur), unit), limitToString(uint64(rlimit.Max), unit))
+}
+
+// FdLimits returns the soft and hard limits for file descriptors.
+func FdLimits() string {
+	return getLimits(syscall.RLIMIT_NOFILE, "")
+}

cmd/prometheus/limits_windows.go

@@ -19,3 +19,8 @@ package main
 func FdLimits() string {
 	return "N/A"
 }
+
+// VmLimits not supported on Windows
+func VmLimits() string {
+	return "N/A"
+}

cmd/prometheus/main.go

@@ -231,6 +231,7 @@ func main() {
 	level.Info(logger).Log("build_context", version.BuildContext())
 	level.Info(logger).Log("host_details", Uname())
 	level.Info(logger).Log("fd_limits", FdLimits())
+	level.Info(logger).Log("vm_limits", VmLimits())
 
 	var (
 		localStorage  = &tsdb.ReadyStorage{}

cmd/prometheus/vmlimits_default.go

@@ -1,4 +1,4 @@
-// Copyright 2017 The Prometheus Authors
+// Copyright 2018 The Prometheus Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -12,21 +12,15 @@
 // limitations under the License.
 
 // +build !windows
+// +build !openbsd
 
 package main
 
 import (
-	"fmt"
-	"log"
 	"syscall"
 )
 
-// FdLimits returns the soft and hard limits for file descriptors
-func FdLimits() string {
-	flimit := syscall.Rlimit{}
-	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &flimit)
-	if err != nil {
-		log.Fatal("Error!")
-	}
-	return fmt.Sprintf("(soft=%d, hard=%d)", flimit.Cur, flimit.Max)
+// VmLimits returns the soft and hard limits for virtual memory.
+func VmLimits() string {
+	return getLimits(syscall.RLIMIT_AS, "b")
 }

cmd/prometheus/vmlimits_openbsd.go

@@ -0,0 +1,25 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build openbsd
+
+package main
+
+import (
+	"syscall"
+)
+
+// VmLimits returns the soft and hard limits for virtual memory.
+func VmLimits() string {
+	return getLimits(syscall.RLIMIT_DATA, "b")
+}