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fix: update docker memory usage calculation (#10491)
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@101100
101100 authored Jan 28, 2022
1 parent 531d7bb commit ac65eb6
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Showing 2 changed files with 177 additions and 2 deletions.
156 changes: 156 additions & 0 deletions plugins/inputs/docker/docker_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -265,6 +265,162 @@ func TestDockerGatherContainerStats(t *testing.T) {
acc.AssertDoesNotContainsTaggedFields(t, "docker_container_cpu", cpu3fields, cputags)
}

func TestDockerMemoryExcludesCache(t *testing.T) {
var acc testutil.Accumulator
stats := testStats()

tags := map[string]string{
"container_name": "redis",
"container_image": "redis/image",
}

d := &Docker{
Log: testutil.Logger{},
}

delete(stats.MemoryStats.Stats, "cache")
delete(stats.MemoryStats.Stats, "inactive_file")
delete(stats.MemoryStats.Stats, "total_inactive_file")

// set cgroup v2 cache value
stats.MemoryStats.Stats["inactive_file"] = 9

d.parseContainerStats(stats, &acc, tags, "123456789", "linux")

// test docker_container_mem measurement
memfields := map[string]interface{}{
"active_anon": uint64(0),
"active_file": uint64(1),
"container_id": "123456789",
"fail_count": uint64(1),
"hierarchical_memory_limit": uint64(0),
"inactive_anon": uint64(0),
"inactive_file": uint64(9),
"limit": uint64(2000),
"mapped_file": uint64(0),
"max_usage": uint64(1001),
"pgfault": uint64(2),
"pgmajfault": uint64(0),
"pgpgin": uint64(0),
"pgpgout": uint64(0),
"rss_huge": uint64(0),
"rss": uint64(0),
"total_active_anon": uint64(0),
"total_active_file": uint64(0),
"total_cache": uint64(0),
"total_inactive_anon": uint64(0),
"total_mapped_file": uint64(0),
"total_pgfault": uint64(0),
"total_pgmajfault": uint64(0),
"total_pgpgin": uint64(4),
"total_pgpgout": uint64(0),
"total_rss_huge": uint64(444),
"total_rss": uint64(44),
"total_unevictable": uint64(0),
"total_writeback": uint64(55),
"unevictable": uint64(0),
"usage_percent": float64(55.1), // 1102 / 2000
"usage": uint64(1102),
"writeback": uint64(0),
}

acc.AssertContainsTaggedFields(t, "docker_container_mem", memfields, tags)
acc.ClearMetrics()

// set cgroup v1 cache value (has priority over cgroups v2)
stats.MemoryStats.Stats["total_inactive_file"] = 7

d.parseContainerStats(stats, &acc, tags, "123456789", "linux")

// test docker_container_mem measurement
memfields = map[string]interface{}{
"active_anon": uint64(0),
"active_file": uint64(1),
// "cache": uint64(0),
"container_id": "123456789",
"fail_count": uint64(1),
"hierarchical_memory_limit": uint64(0),
"inactive_anon": uint64(0),
"inactive_file": uint64(9),
"limit": uint64(2000),
"mapped_file": uint64(0),
"max_usage": uint64(1001),
"pgfault": uint64(2),
"pgmajfault": uint64(0),
"pgpgin": uint64(0),
"pgpgout": uint64(0),
"rss_huge": uint64(0),
"rss": uint64(0),
"total_active_anon": uint64(0),
"total_active_file": uint64(0),
"total_cache": uint64(0),
"total_inactive_anon": uint64(0),
"total_inactive_file": uint64(7),
"total_mapped_file": uint64(0),
"total_pgfault": uint64(0),
"total_pgmajfault": uint64(0),
"total_pgpgin": uint64(4),
"total_pgpgout": uint64(0),
"total_rss_huge": uint64(444),
"total_rss": uint64(44),
"total_unevictable": uint64(0),
"total_writeback": uint64(55),
"unevictable": uint64(0),
"usage_percent": float64(55.2), // 1104 / 2000
"usage": uint64(1104),
"writeback": uint64(0),
}

acc.AssertContainsTaggedFields(t, "docker_container_mem", memfields, tags)
acc.ClearMetrics()

// set Docker 19.03 and older cache value (has priority over cgroups v1 and v2)
stats.MemoryStats.Stats["cache"] = 16

d.parseContainerStats(stats, &acc, tags, "123456789", "linux")

// test docker_container_mem measurement
memfields = map[string]interface{}{
"active_anon": uint64(0),
"active_file": uint64(1),
"cache": uint64(16),
"container_id": "123456789",
"fail_count": uint64(1),
"hierarchical_memory_limit": uint64(0),
"inactive_anon": uint64(0),
"inactive_file": uint64(9),
"limit": uint64(2000),
"mapped_file": uint64(0),
"max_usage": uint64(1001),
"pgfault": uint64(2),
"pgmajfault": uint64(0),
"pgpgin": uint64(0),
"pgpgout": uint64(0),
"rss_huge": uint64(0),
"rss": uint64(0),
"total_active_anon": uint64(0),
"total_active_file": uint64(0),
"total_cache": uint64(0),
"total_inactive_anon": uint64(0),
"total_inactive_file": uint64(7),
"total_mapped_file": uint64(0),
"total_pgfault": uint64(0),
"total_pgmajfault": uint64(0),
"total_pgpgin": uint64(4),
"total_pgpgout": uint64(0),
"total_rss_huge": uint64(444),
"total_rss": uint64(44),
"total_unevictable": uint64(0),
"total_writeback": uint64(55),
"unevictable": uint64(0),
"usage_percent": float64(54.75), // 1095 / 2000
"usage": uint64(1095),
"writeback": uint64(0),
}

acc.AssertContainsTaggedFields(t, "docker_container_mem", memfields, tags)
}

func TestDocker_WindowsMemoryContainerStats(t *testing.T) {
var acc testutil.Accumulator

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23 changes: 21 additions & 2 deletions plugins/inputs/docker/stats_helpers.go
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Original file line number Diff line number Diff line change
Expand Up @@ -40,9 +40,28 @@ func calculateCPUPercentWindows(v *types.StatsJSON) float64 {
}

// CalculateMemUsageUnixNoCache calculate memory usage of the container.
// Page cache is intentionally excluded to avoid misinterpretation of the output.
// Cache is intentionally excluded to avoid misinterpretation of the output.
//
// On Docker 19.03 and older, the result is `mem.Usage - mem.Stats["cache"]`.
// On new docker with cgroup v1 host, the result is `mem.Usage - mem.Stats["total_inactive_file"]`.
// On new docker with cgroup v2 host, the result is `mem.Usage - mem.Stats["inactive_file"]`.
//
// This definition is designed to be consistent with past values and the latest docker CLI
// * https://github.com/docker/cli/blob/6e2838e18645e06f3e4b6c5143898ccc44063e3b/cli/command/container/stats_helpers.go#L239
func CalculateMemUsageUnixNoCache(mem types.MemoryStats) float64 {
return float64(mem.Usage - mem.Stats["cache"])
// Docker 19.03 and older
if v, isOldDocker := mem.Stats["cache"]; isOldDocker && v < mem.Usage {
return float64(mem.Usage - v)
}
// cgroup v1
if v, isCgroup1 := mem.Stats["total_inactive_file"]; isCgroup1 && v < mem.Usage {
return float64(mem.Usage - v)
}
// cgroup v2
if v := mem.Stats["inactive_file"]; v < mem.Usage {
return float64(mem.Usage - v)
}
return float64(mem.Usage)
}

func CalculateMemPercentUnixNoCache(limit float64, usedNoCache float64) float64 {
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