From b1bfb593942acac6d965c608591a4f8fb77c85bb Mon Sep 17 00:00:00 2001
From: hc-github-team-nomad-core
 <82989552+hc-github-team-nomad-core@users.noreply.github.com>
Date: Wed, 19 Jul 2023 15:50:34 -0500
Subject: [PATCH] Backport of metrics: report task memory_max value into
 release/1.6.x (#18004)

This pull request was automerged via backport-assistant
---
 .changelog/17938.txt                                  | 3 +++
 client/allocrunner/taskrunner/task_runner.go          | 6 ++++++
 website/content/docs/operations/metrics-reference.mdx | 1 +
 3 files changed, 10 insertions(+)
 create mode 100644 .changelog/17938.txt

diff --git a/.changelog/17938.txt b/.changelog/17938.txt
new file mode 100644
index 000000000..ab6c87bd6
--- /dev/null
+++ b/.changelog/17938.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+metrics: Add `allocs.memory.max_allocated` to report the value of tasks' `memory_max` resource value
+```
diff --git a/client/allocrunner/taskrunner/task_runner.go b/client/allocrunner/taskrunner/task_runner.go
index d173913f2..3f64299ed 100644
--- a/client/allocrunner/taskrunner/task_runner.go
+++ b/client/allocrunner/taskrunner/task_runner.go
@@ -1482,9 +1482,11 @@ func (tr *TaskRunner) UpdateStats(ru *cstructs.TaskResourceUsage) {
 func (tr *TaskRunner) setGaugeForMemory(ru *cstructs.TaskResourceUsage) {
 	alloc := tr.Alloc()
 	var allocatedMem float32
+	var allocatedMemMax float32
 	if taskRes := alloc.AllocatedResources.Tasks[tr.taskName]; taskRes != nil {
 		// Convert to bytes to match other memory metrics
 		allocatedMem = float32(taskRes.Memory.MemoryMB) * 1024 * 1024
+		allocatedMemMax = float32(taskRes.Memory.MemoryMaxMB) * 1024 * 1024
 	}
 
 	ms := ru.ResourceUsage.MemoryStats
@@ -1508,6 +1510,10 @@ func (tr *TaskRunner) setGaugeForMemory(ru *cstructs.TaskResourceUsage) {
 		metrics.SetGaugeWithLabels([]string{"client", "allocs", "memory", "allocated"},
 			allocatedMem, tr.baseLabels)
 	}
+	if allocatedMemMax > 0 {
+		metrics.SetGaugeWithLabels([]string{"client", "allocs", "memory", "max_allocated"},
+			allocatedMemMax, tr.baseLabels)
+	}
 }
 
 // TODO Remove Backwardscompat or use tr.Alloc()?
diff --git a/website/content/docs/operations/metrics-reference.mdx b/website/content/docs/operations/metrics-reference.mdx
index 369872855..35749c13e 100644
--- a/website/content/docs/operations/metrics-reference.mdx
+++ b/website/content/docs/operations/metrics-reference.mdx
@@ -205,6 +205,7 @@ task driver; not all task drivers can provide all metrics.
 | `nomad.client.allocs.memory.cache`            | Amount of memory cached by the task                               | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |
 | `nomad.client.allocs.memory.kernel_max_usage` | Maximum amount of memory ever used by the kernel for this task    | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |
 | `nomad.client.allocs.memory.kernel_usage`     | Amount of memory used by the kernel for this task                 | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |
+| `nomad.client.allocs.memory.max_allocated`    | Maximum amount of oversubscription memory allocated by the task   | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |
 | `nomad.client.allocs.memory.max_usage`        | Maximum amount of memory ever used by the task                    | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |
 | `nomad.client.allocs.memory.rss`              | Amount of RSS memory consumed by the task                         | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |
 | `nomad.client.allocs.memory.swap`             | Amount of memory swapped by the task                              | Bytes       | Gauge   | alloc_id, host, job, namespace, task, task_group |