From 53f40063b31fd9ef3d92e7fc22e821d0f71ac46d Mon Sep 17 00:00:00 2001
From: Sebastian Borza <sborza@alumni.princeton.edu>
Date: Thu, 14 Jul 2016 15:18:55 -0500
Subject: [PATCH] Moving cgroup path name to field from tag to reduce
cardinality (#1457)
adding assertContainsFields function to cgroup_test for custom validation
---
plugins/inputs/cgroup/README.md | 5 +-
plugins/inputs/cgroup/cgroup_linux.go | 5 +-
plugins/inputs/cgroup/cgroup_test.go | 84 +++++++++++++++------------
3 files changed, 53 insertions(+), 41 deletions(-)
diff --git a/plugins/inputs/cgroup/README.md b/plugins/inputs/cgroup/README.md
index ab06342b..feb332dd 100644
--- a/plugins/inputs/cgroup/README.md
+++ b/plugins/inputs/cgroup/README.md
@@ -33,8 +33,9 @@ KEY1 VAL1\n
### Tags:
-All measurements have the following tags:
- - path
+Measurements don't have any specific tags unless you define them at the telegraf level (defaults). We
+used to have the path listed as a tag, but to keep cardinality in check it's easier to move this
+value to a field. Thanks @sebito91!
### Configuration:
diff --git a/plugins/inputs/cgroup/cgroup_linux.go b/plugins/inputs/cgroup/cgroup_linux.go
index e8ba6f88..ecaf8126 100644
--- a/plugins/inputs/cgroup/cgroup_linux.go
+++ b/plugins/inputs/cgroup/cgroup_linux.go
@@ -56,10 +56,9 @@ func (g *CGroup) gatherDir(dir string, acc telegraf.Accumulator) error {
return err
}
}
+ fields["path"] = dir
- tags := map[string]string{"path": dir}
-
- acc.AddFields(metricName, fields, tags)
+ acc.AddFields(metricName, fields, nil)
return nil
}
diff --git a/plugins/inputs/cgroup/cgroup_test.go b/plugins/inputs/cgroup/cgroup_test.go
index 206b51f6..ff9b8d7a 100644
--- a/plugins/inputs/cgroup/cgroup_test.go
+++ b/plugins/inputs/cgroup/cgroup_test.go
@@ -3,10 +3,13 @@
package cgroup
import (
+ "fmt"
"testing"
"github.com/influxdata/telegraf/testutil"
+ "github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
+ "reflect"
)
var cg1 = &CGroup{
@@ -21,15 +24,32 @@ var cg1 = &CGroup{
},
}
+func assertContainsFields(a *testutil.Accumulator, t *testing.T, measurement string, fieldSet []map[string]interface{}) {
+ a.Lock()
+ defer a.Unlock()
+
+ numEquals := 0
+ for _, p := range a.Metrics {
+ if p.Measurement == measurement {
+ for _, fields := range fieldSet {
+ if reflect.DeepEqual(fields, p.Fields) {
+ numEquals++
+ }
+ }
+ }
+ }
+
+ if numEquals != len(fieldSet) {
+ assert.Fail(t, fmt.Sprintf("only %d of %d are equal", numEquals, len(fieldSet)))
+ }
+}
+
func TestCgroupStatistics_1(t *testing.T) {
var acc testutil.Accumulator
err := cg1.Gather(&acc)
require.NoError(t, err)
- tags := map[string]string{
- "path": "testdata/memory",
- }
fields := map[string]interface{}{
"memory.stat.cache": 1739362304123123123,
"memory.stat.rss": 1775325184,
@@ -42,8 +62,9 @@ func TestCgroupStatistics_1(t *testing.T) {
"memory.limit_in_bytes": 223372036854771712,
"memory.use_hierarchy": "12-781",
"notify_on_release": 0,
+ "path": "testdata/memory",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
+ assertContainsFields(&acc, t, "cgroup", []map[string]interface{}{fields})
}
// ======================================================================
@@ -59,16 +80,14 @@ func TestCgroupStatistics_2(t *testing.T) {
err := cg2.Gather(&acc)
require.NoError(t, err)
- tags := map[string]string{
- "path": "testdata/cpu",
- }
fields := map[string]interface{}{
"cpuacct.usage_percpu.0": -1452543795404,
"cpuacct.usage_percpu.1": 1376681271659,
"cpuacct.usage_percpu.2": 1450950799997,
"cpuacct.usage_percpu.3": -1473113374257,
+ "path": "testdata/cpu",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
+ assertContainsFields(&acc, t, "cgroup", []map[string]interface{}{fields})
}
// ======================================================================
@@ -84,18 +103,16 @@ func TestCgroupStatistics_3(t *testing.T) {
err := cg3.Gather(&acc)
require.NoError(t, err)
- tags := map[string]string{
- "path": "testdata/memory/group_1",
- }
fields := map[string]interface{}{
"memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_1",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
- tags = map[string]string{
- "path": "testdata/memory/group_2",
+ fieldsTwo := map[string]interface{}{
+ "memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_2",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
+ assertContainsFields(&acc, t, "cgroup", []map[string]interface{}{fields, fieldsTwo})
}
// ======================================================================
@@ -111,23 +128,22 @@ func TestCgroupStatistics_4(t *testing.T) {
err := cg4.Gather(&acc)
require.NoError(t, err)
- tags := map[string]string{
- "path": "testdata/memory/group_1/group_1_1",
- }
fields := map[string]interface{}{
"memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_1/group_1_1",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
- tags = map[string]string{
- "path": "testdata/memory/group_1/group_1_2",
+ fieldsTwo := map[string]interface{}{
+ "memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_1/group_1_2",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
- tags = map[string]string{
- "path": "testdata/memory/group_2",
+ fieldsThree := map[string]interface{}{
+ "memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_2",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
+
+ assertContainsFields(&acc, t, "cgroup", []map[string]interface{}{fields, fieldsTwo, fieldsThree})
}
// ======================================================================
@@ -143,18 +159,16 @@ func TestCgroupStatistics_5(t *testing.T) {
err := cg5.Gather(&acc)
require.NoError(t, err)
- tags := map[string]string{
- "path": "testdata/memory/group_1/group_1_1",
- }
fields := map[string]interface{}{
"memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_1/group_1_1",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
- tags = map[string]string{
- "path": "testdata/memory/group_2/group_1_1",
+ fieldsTwo := map[string]interface{}{
+ "memory.limit_in_bytes": 223372036854771712,
+ "path": "testdata/memory/group_2/group_1_1",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
+ assertContainsFields(&acc, t, "cgroup", []map[string]interface{}{fields, fieldsTwo})
}
// ======================================================================
@@ -170,13 +184,11 @@ func TestCgroupStatistics_6(t *testing.T) {
err := cg6.Gather(&acc)
require.NoError(t, err)
- tags := map[string]string{
- "path": "testdata/memory",
- }
fields := map[string]interface{}{
"memory.usage_in_bytes": 3513667584,
"memory.use_hierarchy": "12-781",
"memory.kmem.limit_in_bytes": 9223372036854771712,
+ "path": "testdata/memory",
}
- acc.AssertContainsTaggedFields(t, "cgroup", fields, tags)
+ assertContainsFields(&acc, t, "cgroup", []map[string]interface{}{fields})
}
--
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