[Metricbeat] Bump elastic-agent-system-metrics for zswap and cgroups v2 CPU CFS data (#49098) (#49400)

Bumps the elastic-agent-system-metrics dependency to [v0.14.3](https://github.com/elastic/elastic-agent-system-metrics/releases/tag/v0.14.3), [v0.14.2](https://github.com/elastic/elastic-agent-system-metrics/releases/tag/v0.14.2) also included.

### What's Changed
* Add Zswap Metrics by @orestisfl in elastic/elastic-agent-system-metrics#279
* PULL_REQUEST_TEMPLATE: Remove reference to non-existant CHANGELOG.md by @orestisfl in elastic/elastic-agent-system-metrics#286
* fix: remove shared context timeout from matrix tests by @orestisfl in elastic/elastic-agent-system-metrics#285
* Enable modernize linter and apply suggestions by @orestisfl in elastic/elastic-agent-system-metrics#287
* Use json omitzero for struct-typed fields in cgroup structs by @orestisfl in elastic/elastic-agent-system-metrics#288
* [cgv2] Add CPU CFS quota, period, and weight metrics by @orestisfl in elastic/elastic-agent-system-metrics#281
* Add missing zswap debug metrics by @orestisfl in elastic/elastic-agent-system-metrics#289

## Disruptive User Impact

None. New features.

## How to test this PR locally

1. Build metricbeat from the branch:

```bash
cd metricbeat
mage build
```

2. Create a test config file `metricbeat.test.yml`:

```yaml
metricbeat.modules:
  - module: system
    period: 5s
    metricsets:
      - memory
      - process
    process.include_top_n:
      by_cpu: 5
      by_memory: 5

output.console:
  pretty: true

logging.level: debug
```

3. Run metricbeat:

```bash
./metricbeat -e -c metricbeat.test.yml
```

4. Verify zswap memory metrics appear in the output (requires Linux with zswap enabled -- check with `cat /sys/module/zswap/parameters/enabled`):

```bash
./metricbeat -e -c metricbeat.test.yml 2>/dev/null | jq 'select(.metricset.name == "memory") | .system.memory.zswap'
```

Expected output (values will vary):

```json
{
  "compressed": 950353920,
  "uncompressed": 3813502976
}
```

5. To also verify the `zswap.debug.*` fields (requires debugfs access), grant the binary the `cap_dac_read_search` capability:

```bash
sudo setcap cap_dac_read_search=+ep metricbeat
```

Then re-run. Expected output with debug fields:

```json
{
  "compressed": 950353920,
  "uncompressed": 3813502976,
  "debug": {
    "decompress_fail": 0,
    "pool_limit_hit": 0,
    "pool_total_size": 950353920,
    "reject_alloc_fail": 0,
    "reject_compress_fail": 0,
    "reject_compress_poor": 0,
    "reject_kmemcache_fail": 0,
    "reject_reclaim_fail": 0,
    "stored_incompressible_pages": 16779,
    "stored_pages": 931031,
    "written_back_pages": 29111
  }
}
```

6. Verify `cfs.weight` appears in process cgroup metrics (requires cgroupsv2):

```bash
./metricbeat -e -c metricbeat.test.yml 2>/dev/null | jq 'select(.metricset.name == "process") | .system.process.cgroup.cpu.cfs.weight // empty'
```

7. Run unit tests:

```bash
cd metricbeat
go test ./module/system/...
```

(cherry picked from commit eeabffa)

Co-authored-by: Orestis Floros <orestis.floros@elastic.co>

Author: mergify[bot]

NOTICE.txt

@@ -11175,11 +11175,11 @@ Contents of probable licence file $GOMODCACHE/github.com/elastic/elastic-agent-l
 
 --------------------------------------------------------------------------------
 Dependency : github.com/elastic/elastic-agent-system-metrics
-Version: v0.14.1
+Version: v0.14.3
 Licence type (autodetected): Apache-2.0
 --------------------------------------------------------------------------------
 
-Contents of probable licence file $GOMODCACHE/github.com/elastic/elastic-agent-system-metrics@v0.14.1/LICENSE.txt:
+Contents of probable licence file $GOMODCACHE/github.com/elastic/elastic-agent-system-metrics@v0.14.3/LICENSE.txt:
 
                                  Apache License
                            Version 2.0, January 2004

changelog/fragments/1772011445-zswap-metrics.yaml

@@ -0,0 +1,45 @@
+# REQUIRED
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: feature
+
+# REQUIRED for all kinds
+# Change summary; a 80ish characters long description of the change.
+summary: Add zswap compressed swap cache metrics to system memory metricset
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# description:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# impact:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# action:
+
+# REQUIRED for all kinds
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: metricbeat
+
+# AUTOMATED
+# OPTIONAL to manually add other PR URLs
+# PR URL: A link the PR that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+# pr: https://github.com/owner/repo/1234
+
+# AUTOMATED
+# OPTIONAL to manually add other issue URLs
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+# issue: https://github.com/owner/repo/1234

changelog/fragments/1772636540-zswap-metrics.yaml

@@ -0,0 +1,45 @@
+# REQUIRED
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: feature
+
+# REQUIRED for all kinds
+# Change summary; a 80ish characters long description of the change.
+summary: Add cgroupv2 CPU metrics to system.process dataset
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# description:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# impact:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# action:
+
+# REQUIRED for all kinds
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: metricbeat
+
+# AUTOMATED
+# OPTIONAL to manually add other PR URLs
+# PR URL: A link the PR that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+# pr: https://github.com/owner/repo/1234
+
+# AUTOMATED
+# OPTIONAL to manually add other issue URLs
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+# issue: https://github.com/owner/repo/1234

docs/reference/metricbeat/exported-fields-system.md

@@ -725,7 +725,7 @@ Actual memory used and free.
 
 
 **`system.memory.actual.free`**
-:   Actual free memory in bytes. It is calculated based on the OS. On Linux this value will be MemAvailable from /proc/meminfo,  or calculated from free memory plus caches and buffers if /proc/meminfo is not available. On OSX it is a sum of free memory and the inactive memory. On Windows, it is equal to `system.memory.free`.
+:   Actual free memory in bytes. It is calculated based on the OS. On Linux this value will be MemAvailable from /proc/meminfo, or calculated from free memory plus caches and buffers if /proc/meminfo is not available. On OSX it is a sum of free memory and the inactive memory. On Windows, it is equal to `system.memory.free`.
 
     type: long
 
@@ -776,6 +776,98 @@ This group contains statistics related to the swap memory usage on the system.
     format: percent
 
 
+## zswap [_zswap]
+
+Metrics for the zswap compressed swap cache. Available on Linux when zswap is enabled.
+
+**`system.memory.zswap.compressed`**
+:   Current compressed size of data stored in zswap.
+
+    type: long
+
+    format: bytes
+
+
+**`system.memory.zswap.uncompressed`**
+:   Original uncompressed size of data stored in zswap.
+
+    type: long
+
+    format: bytes
+
+
+## debug [_debug]
+
+Detailed zswap statistics from /sys/kernel/debug/zswap. Requires debugfs to be mounted and accessible.
+
+**`system.memory.zswap.debug.decompress_fail`**
+:   Number of load or writeback attempts that failed due to decompression failure.
+
+    type: long
+
+
+**`system.memory.zswap.debug.pool_limit_hit`**
+:   Number of times the zswap pool limit was hit, as configured by the zswap.max_pool_percent kernel parameter.
+
+    type: long
+
+
+**`system.memory.zswap.debug.pool_total_size`**
+:   Total size of the zswap pool in bytes.
+
+    type: long
+
+    format: bytes
+
+
+**`system.memory.zswap.debug.reject_alloc_fail`**
+:   Number of store attempts that failed because the underlying allocator could not get memory.
+
+    type: long
+
+
+**`system.memory.zswap.debug.reject_compress_fail`**
+:   Number of store attempts that failed due to compression algorithm failure.
+
+    type: long
+
+
+**`system.memory.zswap.debug.reject_compress_poor`**
+:   Number of store attempts rejected because the compressed page was too big for the allocator to optimally store.
+
+    type: long
+
+
+**`system.memory.zswap.debug.reject_kmemcache_fail`**
+:   Number of store attempts that failed because the entry metadata could not be allocated (rare).
+
+    type: long
+
+
+**`system.memory.zswap.debug.reject_reclaim_fail`**
+:   Number of store attempts that failed due to a reclaim failure after pool limit was reached.
+
+    type: long
+
+
+**`system.memory.zswap.debug.stored_incompressible_pages`**
+:   Number of incompressible pages currently stored in zswap.
+
+    type: long
+
+
+**`system.memory.zswap.debug.stored_pages`**
+:   Number of pages currently stored in zswap.
+
+    type: long
+
+
+**`system.memory.zswap.debug.written_back_pages`**
+:   Number of pages written back from zswap to swap when pool limit was reached.
+
+    type: long
+
+
 ## network [_network]
 
 `network` contains network IO metrics for a single network interface.
@@ -1238,6 +1330,12 @@ cgroupv2 stats
     type: long
 
 
+**`system.process.cgroup.cpu.cfs.weight`**
+:   CPU weight for the cgroup (cgroupv2). Used by the CFS scheduler to determine the share of CPU time available to the cgroup. Valid values range from 1 to 10000. The default value is 100.
+
+    type: long
+
+
 **`system.process.cgroup.cpu.rt.period.us`**
 :   Period of time in microseconds for how regularly a cgroup's access to CPU resources is reallocated.
 

go.mod

@@ -173,7 +173,7 @@ require (
 	github.com/elastic/ebpfevents v0.8.0
 	github.com/elastic/elastic-agent-autodiscover v0.10.2
 	github.com/elastic/elastic-agent-libs v0.33.3
-	github.com/elastic/elastic-agent-system-metrics v0.14.1
+	github.com/elastic/elastic-agent-system-metrics v0.14.3
 	github.com/elastic/go-elasticsearch/v8 v8.19.0
 	github.com/elastic/go-freelru v0.16.0
 	github.com/elastic/go-quark v0.3.0

go.sum

@@ -376,8 +376,8 @@ github.com/elastic/elastic-agent-client/v7 v7.18.0 h1:zXdoErqECfvRjj1c+1Ko4VGuUn
 github.com/elastic/elastic-agent-client/v7 v7.18.0/go.mod h1:ChFjpIfSsQOnhWT3se5Euw/o8P4Vf77FxeObE/vUfSc=
 github.com/elastic/elastic-agent-libs v0.33.3 h1:Gsq5FA29sUbbZVJbeLCKPyRkAxCrOhv3VtXvuG9Uu6k=
 github.com/elastic/elastic-agent-libs v0.33.3/go.mod h1:0xUg7alsNE/WhY9DZRIdTYW75nqSHC1octIAg//j/PQ=
-github.com/elastic/elastic-agent-system-metrics v0.14.1 h1:XdV3KWbug/M1dkn8h9Yth9pfdyeFR2Z1iqaypX+ohBg=
-github.com/elastic/elastic-agent-system-metrics v0.14.1/go.mod h1:JNfnZrC0viAjlJRUzQKKuMpDlXgjXBn4WdWEXQF7jcA=
+github.com/elastic/elastic-agent-system-metrics v0.14.3 h1:v867kcgCVguOX3AYIHEVn2RNracdH40FqqXiZq71pDU=
+github.com/elastic/elastic-agent-system-metrics v0.14.3/go.mod h1:JNfnZrC0viAjlJRUzQKKuMpDlXgjXBn4WdWEXQF7jcA=
 github.com/elastic/elastic-transport-go/v8 v8.8.0 h1:7k1Ua+qluFr6p1jfJjGDl97ssJS/P7cHNInzfxgBQAo=
 github.com/elastic/elastic-transport-go/v8 v8.8.0/go.mod h1:YLHer5cj0csTzNFXoNQ8qhtGY1GTvSqPnKWKaqQE3Hk=
 github.com/elastic/fsevents v0.0.0-20181029231046-e1d381a4d270 h1:cWPqxlPtir4RoQVCpGSRXmLqjEHpJKbR60rxh1nQZY4=