15872 FIX This Werk fixes misbehaved metrics after an upgrade

SUP-16019

Change-Id: I8e8876f66054d82daab9904645e309516fa831e8

.werks/15872

@@ -0,0 +1,15 @@
+Title: This Werk fixes misbehaved metrics after an upgrade
+Class: fix
+Compatible: compat
+Component: checks
+Date: 1697611822
+Edition: cre
+Level: 1
+Version: 2.3.0b1
+
+After an upgrade various plugins metrics would misbehave, until eventually settling again.
+More specificly: All averaged metrics would forget the previously recorded values.
+As a result, the "averaged" metric follows the original one very closely.
+After a few values are recorded the desired smoothing effect of the averaging will start to show.
+The time it takes for the metric to stabilise depends on the configured or implemented weights (<i>"Backlog in minutes"</i>).
+

omd/packages/omd/omdlib/tmpfs.py

@@ -263,6 +263,7 @@ def save_tmpfs_dump(site: SiteContext) -> None:
     save_paths = [
         Path(site.tmp_dir) / "check_mk" / "piggyback",
         Path(site.tmp_dir) / "check_mk" / "piggyback_sources",
+        Path(site.tmp_dir) / "check_mk" / "counters",
     ]
 
     dump_path = _tmpfs_dump_path(site)

tests/testlib/site.py

@@ -38,7 +38,7 @@
 
 import livestatus
 
-from cmk.utils.paths import piggyback_dir, piggyback_source_dir
+from cmk.utils.paths import counters_dir, piggyback_dir, piggyback_source_dir
 from cmk.utils.version import Edition
 
 logger = logging.getLogger(__name__)
@@ -1506,7 +1506,7 @@ def interactive_update(
             logger.debug("OMD automation logfile: %s", logfile.read())
 
         # tmpfs should have been restored:
-        # TODO: assert os.path.exists(site.path(counters_dir))
+        assert os.path.exists(site.path(counters_dir))
         assert os.path.exists(site.path(str(piggyback_dir)))
         assert os.path.exists(site.path(str(piggyback_source_dir)))