Modify how MemCap collects util and saturation
This CL modifies how MemCap collects utilization such that
the only the percentage usage of main memory is captured. It also
modifies how saturation is collected such that a percentage of the
total Swap memory is used as a threshold. If total swap memory is 0,
a threshold is placed on utilization. This CL also modifies unit tests
accordingly.
Change-Id: I066d55c534c857572790598869ab3c9078708654
Reviewed-on: https://cos-review.googlesource.com/c/cos/tools/+/21110
Reviewed-by: Dexter Rivera <riverade@google.com>
Tested-by: Dexter Rivera <riverade@google.com>
Cloud-Build: GCB Service account <228075978874@cloudbuild.gserviceaccount.com>
diff --git a/src/pkg/nodeprofiler/profiler/components.go b/src/pkg/nodeprofiler/profiler/components.go
index db2f7ee..0097d4b 100644
--- a/src/pkg/nodeprofiler/profiler/components.go
+++ b/src/pkg/nodeprofiler/profiler/components.go
@@ -215,7 +215,10 @@
// AdditionalInformation returns additional information unique to the
// the MemCap component.
func (m *MemCap) AdditionalInformation() string {
- return ""
+ info := "The utilization value for this component was calculated as a " +
+ "percentage of total Main memory while saturation was calculated based on " +
+ "a threshold placed on total Swap memory "
+ return info
}
// Name returns the name of the Memory capacity component.
@@ -244,12 +247,8 @@
if !muPresent {
return fmt.Errorf("missing free's Mem row and used column")
}
- swapUsed, suPresent := parsedOutput["Swap:used"]
- if !suPresent {
- return fmt.Errorf("missing free's Swap row and used column")
- }
- memory := [][]string{memUsed, swapUsed}
+ memory := [][]string{memUsed}
var used int
for _, mem := range memory {
sum, err := utils.SumAtoi(mem)
@@ -258,41 +257,37 @@
}
used += sum
}
-
- total, err := m.calculateTotalMemory(outputs)
+ // get total [main] memory
+ total, err := m.calculateTotalMemory("Mem", outputs)
if err != nil {
return err
}
- m.metrics.Utilization = math.Round((float64(used)/float64(total))*1000) / 1000
+ // get value as percentage and rount it off
+ util := (float64(used) / float64(total)) * 100
+ m.metrics.Utilization = math.Round((util)*1000) / 1000
+
return nil
}
-// calculateTotalMemory calculates the total memory on the system.
-// It does this by summing the total Main and total Swap memory which
-// can be found on free's "Mem" row + "total" column, and "Swap" row +
-// "total" column.
-func (m *MemCap) calculateTotalMemory(outputs map[string]utils.ParsedOutput) (int, error) {
+// calculateTotalMemory calculates the total main or swap memory on the system,
+// depending on what string passed in: "Mem" or "Swap". If "Mem" is passed in,
+// it returns the value found on free's "Mem" row + "total" column and if "Swap"
+// is passed in, it returns the value on free's "Swap" row + "total" column.
+func (m *MemCap) calculateTotalMemory(mem string, outputs map[string]utils.ParsedOutput) (int, error) {
cmd := "free"
parsedOutput, ok := outputs[cmd]
if !ok {
return 0, fmt.Errorf("missing output for %q", cmd)
}
- memTotal, mtPresent := parsedOutput["Mem:total"]
+ memType := mem + ":total"
+ memTotal, mtPresent := parsedOutput[memType]
if !mtPresent {
- return 0, fmt.Errorf("missing free's Mem row and total column")
+ return 0, fmt.Errorf("missing free's %s row and total column", mem)
}
- swapTotal, stPresent := parsedOutput["Swap:total"]
- if !stPresent {
- return 0, fmt.Errorf("missing free's Swap row and total column")
- }
- memory := [][]string{memTotal, swapTotal}
- var total int
- for _, mem := range memory {
- sum, err := utils.SumAtoi(mem)
- if err != nil {
- return 0, err
- }
- total += sum
+
+ total, err := utils.SumAtoi(memTotal)
+ if err != nil {
+ return 0, err
}
return total, nil
}
@@ -306,10 +301,10 @@
// memory swapped in and out of disks can be found on vmstat's 'si'
// (swapped in) and 'so' (swapped to) columns.
func (m *MemCap) CollectSaturation(outputs map[string]utils.ParsedOutput) error {
- cmd := "vmstat"
- parsedOutput, ok := outputs[cmd]
+ vmstatCmd := "vmstat"
+ parsedOutput, ok := outputs[vmstatCmd]
if !ok {
- return fmt.Errorf("missing output for %q", cmd)
+ return fmt.Errorf("missing output for %q", vmstatCmd)
}
si, siPresent := parsedOutput["si"]
if !siPresent {
@@ -328,14 +323,29 @@
}
swaps += sum
}
- average := swaps / len(si)
- total, err := m.calculateTotalMemory(outputs)
+ // get total [Swap] memory
+ total, err := m.calculateTotalMemory("Swap", outputs)
if err != nil {
return err
}
- // ten percent of total memory
- threshold := 0.1 * float64(total)
- m.metrics.Saturation = float64(average) > threshold
+ // since metrics from free are in megabytes and those from vmstat are
+ // in kilobytes
+ totalBytes := total * 1024
+
+ // ten percent of total swap memory
+ log.Infof("swaps is %d and total swap memory is %d", swaps, totalBytes)
+
+ var threshold float64
+ // accounts for cases where swap memory is 0
+ if totalBytes == 0 {
+ // threshold set as 95 percent utilization
+ threshold = 95
+ m.metrics.Saturation = m.metrics.Utilization > threshold
+ } else {
+ // threshold set as 10 percent of total swap memory
+ threshold = 0.1 * float64(totalBytes)
+ m.metrics.Saturation = float64(swaps) > threshold
+ }
return nil
}
diff --git a/src/pkg/nodeprofiler/profiler/components_test.go b/src/pkg/nodeprofiler/profiler/components_test.go
index 78fb318..b9fadf9 100644
--- a/src/pkg/nodeprofiler/profiler/components_test.go
+++ b/src/pkg/nodeprofiler/profiler/components_test.go
@@ -78,7 +78,7 @@
"Swap:total": {"0"},
},
},
- want: 0.001,
+ want: 0.09,
},
{
name: "missing titles",
@@ -286,12 +286,11 @@
component: &MemCap{"fake", &USEMetrics{}},
outputs: map[string]utils.ParsedOutput{
"vmstat": {
- "si": {"0", "0", "3"},
- "so": {"0", "1", "5"},
+ "si": {"0", "7", "3"},
+ "so": {"0", "8", "5"},
},
"free": {
- "Mem:total": {"14520"},
- "Swap:total": {"0"},
+ "Swap:total": {"701"},
},
},
},
