Mask apt-daily timers in SPEC CPU profiles to prevent VC restarts on Ubuntu 24.04 (#694)

* Mask apt-daily timers in SPEC CPU profiles to prevent VC restarts on Ubuntu 24.04

On Ubuntu 24.04, apt-daily-upgrade.timer fires between 06:00-07:00 UTC
and triggers needrestart (default installed on 24.04, not 22.04) which
auto-restarts services whose libraries were updated. This has been
observed to SIGKILL VirtualClient mid-run, desynchronizing packed
SPEC CPU experiments and invalidating results.

Analysis of ~4,700 Ubuntu 24.04 SYSAUTO VMs showed ~29% restart rate,
with 80% concentrated at hour 6 UTC and minute-of-hour distribution
uniform 0-59 (signature of RandomizedDelaySec=60min on the timer).
Ubuntu 22.04, Windows, and focal VMs showed 0% restarts in the same
window.

Masking both apt-daily.timer and apt-daily-upgrade.timer (plus their
services) as a dependency step at profile startup removes the trigger.
Filtered to linux-x64,linux-arm64 via SupportedPlatforms.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Bump VERSION to 3.1.2 for apt-daily mask change

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Alex Williams-Ferreira <alexwill@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

VERSION

@@ -1 +1 @@
-3.1.1
+3.1.2

src/VirtualClient/VirtualClient.Main/profiles/PERF-SPECCPU-FPRATE.json

@@ -41,6 +41,14 @@
         }
     ],
     "Dependencies": [
+        {
+            "Type": "ExecuteCommand",
+            "Parameters": {
+                "Scenario": "MaskAptDailyTimers",
+                "SupportedPlatforms": "linux-x64,linux-arm64",
+                "Command": "bash -c 'systemctl mask apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; systemctl stop apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; exit 0'"
+            }
+        },
         {
             "Type": "ChocolateyInstallation",
             "Parameters": {

src/VirtualClient/VirtualClient.Main/profiles/PERF-SPECCPU-FPSPEED.json

@@ -41,6 +41,14 @@
         }
     ],
     "Dependencies": [
+        {
+            "Type": "ExecuteCommand",
+            "Parameters": {
+                "Scenario": "MaskAptDailyTimers",
+                "SupportedPlatforms": "linux-x64,linux-arm64",
+                "Command": "bash -c 'systemctl mask apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; systemctl stop apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; exit 0'"
+            }
+        },
         {
             "Type": "ChocolateyInstallation",
             "Parameters": {

src/VirtualClient/VirtualClient.Main/profiles/PERF-SPECCPU-INTRATE.json

@@ -41,6 +41,14 @@
         }
     ],
     "Dependencies": [
+        {
+            "Type": "ExecuteCommand",
+            "Parameters": {
+                "Scenario": "MaskAptDailyTimers",
+                "SupportedPlatforms": "linux-x64,linux-arm64",
+                "Command": "bash -c 'systemctl mask apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; systemctl stop apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; exit 0'"
+            }
+        },
         {
             "Type": "ChocolateyInstallation",
             "Parameters": {

src/VirtualClient/VirtualClient.Main/profiles/PERF-SPECCPU-INTSPEED.json

@@ -41,6 +41,14 @@
         }
     ],
     "Dependencies": [
+        {
+            "Type": "ExecuteCommand",
+            "Parameters": {
+                "Scenario": "MaskAptDailyTimers",
+                "SupportedPlatforms": "linux-x64,linux-arm64",
+                "Command": "bash -c 'systemctl mask apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; systemctl stop apt-daily.timer apt-daily-upgrade.timer apt-daily.service apt-daily-upgrade.service; exit 0'"
+            }
+        },
         {
             "Type": "ChocolateyInstallation",
             "Parameters": {