refactor: raise anonymous RSS threshold from 80% to 90%

Per review feedback, increase _ANON_RSS_THRESHOLD from 0.80 to 0.90
to align with the conservative 98% cgroup threshold. Start stricter
and relax later once fleet data is available.

Co-Authored-By: bot_apk <apk@cognition.ai>

Author: devin-ai-integration[bot]

airbyte_cdk/utils/memory_monitor.py

@@ -34,7 +34,7 @@
 # This dual-condition avoids false positives from reclaimable kernel page cache
 # and file-backed / shared resident pages that inflate VmRSS.
 _CRITICAL_THRESHOLD = 0.98
-_ANON_RSS_THRESHOLD = 0.80
+_ANON_RSS_THRESHOLD = 0.90
 
 # Check interval (every N messages)
 _DEFAULT_CHECK_INTERVAL = 5000
@@ -83,7 +83,7 @@ class MemoryMonitor:
     ``FailureType.system_error`` when *both*:
 
     1. Cgroup usage >= 98% of the container limit (container is near OOM-kill)
-    2. Process anonymous RSS (``RssAnon``) >= 80% of the container limit
+    2. Process anonymous RSS (``RssAnon``) >= 90% of the container limit
        (pressure is from process-private anonymous memory, not elastic kernel
        page cache or file-backed resident pages)
 
@@ -176,7 +176,7 @@ def check_memory_usage(self) -> None:
         **Logging:** WARNING on every check above 95%.
 
         **Fail-fast (when enabled):** If cgroup usage >= 98% *and* process
-        anonymous RSS (``RssAnon``) >= 80% of the container limit, raises
+        anonymous RSS (``RssAnon``) >= 90% of the container limit, raises
         ``AirbyteTracedException`` with ``FailureType.system_error`` so the
         platform receives a clear error message instead of an opaque OOM-kill.
         If ``RssAnon`` is unavailable, logs a warning and skips fail-fast.

unit_tests/utils/test_memory_monitor.py

@@ -30,7 +30,7 @@
 # Anonymous RSS mock values (in kB as they appear in /proc/self/status RssAnon field).
 # VmRSS is intentionally kept high in the "low anon" mock to prove the metric choice matters:
 # VmRSS can be inflated by file-backed pages while RssAnon stays low.
-_MOCK_ANON_HIGH = "RssAnon:\t   820000 kB\n"  # ~82% of 1 GB (above 80% threshold)
+_MOCK_ANON_HIGH = "RssAnon:\t   920000 kB\n"  # ~92% of 1 GB (above 90% threshold)
 _MOCK_ANON_LOW_VMRSS_HIGH = (
     "VmRSS:\t   900000 kB\n"  # ~90% of 1 GB — high total RSS
     "RssAnon:\t   500000 kB\n"  # ~50% of 1 GB — low anonymous RSS