WS5: LPIM / IFI / memory dumps as advise-only server-health recommendations

[erikdarlingdata]

What

Part of the recommendations rebuild. Surfaces three standing server-health gaps as advise-only recommendation cards on the existing recommendations path — no Apply (these need OS / service-account / investigation work, not a sp_configure flip):

Fact key	Condition
CONFIG_IFI_DISABLED	Instant File Initialization off
CONFIG_LPIM_DISABLED	Lock Pages in Memory off
SERVER_MEMORY_DUMPS	sys.dm_server_memory_dumps count > 0

Vertical slice across the Dashboard SQL collector + both apps' C#, mirroring the WS3 config-advisory pattern (CONFIG_MAXDOP / CONFIG_CTFP / …) exactly.

No new Agent job / no live runs

• Extends the existing collect.server_properties_collector, already dispatched by the one Collection job's master collector (install/42_…, ~line 330). No job, schedule, or new proc.
• Code + unit tests only — not run against any live SQL Server. The install/upgrade live test is for the reviewer (see "Not verified live").

Changes

Schema — 3 nullable columns on collect.server_properties (lock_pages_in_memory bit, instant_file_initialization_enabled bit, memory_dump_count integer):

• install/02_create_tables.sql — added to the CREATE TABLE (fresh installs).
• upgrades/2.11.0-to-2.12.0/04_add_server_health_columns.sql — idempotent guarded IF NOT EXISTS (sys.columns) … ALTER … ADD (existing installs), appended to upgrade.txt.

Collector (install/53_collect_server_properties.sql): reads LPIM from sys.dm_os_sys_info.sql_memory_model (2/3 → on, 1 → off); IFI from sys.dm_server_services.instant_file_initialization_enabled (guarded on DMV + column existence, read via dynamic SQL so older builds compile); dumps from COUNT_BIG(*) over sys.dm_server_memory_dumps (DMV-guarded). Each is engine-edition-guarded + wrapped in TRY/CATCH and left NULL when unavailable so the collector never fails; all three are folded into the row_hash so a change re-collects. Dedup/skip + collection_log behavior untouched.

Shared facts (PerformanceMonitor.Analysis, advise-only):

• FactScorer.ScoreConfigFact — each key scores a 0.4 advisory base only when bad (IFI/LPIM Value==0, dumps Value>0), else 0.
• InferenceEngine.ConfigAdvisoryRootKeys — each roots a standalone card below the 0.5 incident threshold (surfaces on a quiet, healthy server).
• FactAdvice — one advice block per key (headline + investigation + copy-paste guidance; no generated Apply T-SQL).
• No RemediationAction / handler / Apply.

Both collectors emit the facts with identical noise-control gating (Dashboard SqlServerFactCollector, Lite DuckDbFactCollector + RemoteCollectorService.ServerProperties + DuckDB schema v27 migration).

Thresholds chosen — ⚠️ please tune

• IFI off → always advisory (low-noise, universally good advice).
• LPIM off → only on non-Express editions with ≥ 32 GB RAM — don't flag tiny instances. The 32 GB floor is the main tuning knob (a shared LpimAdvisoryMinPhysicalMemoryMb const in both collectors).
• Memory dumps → advisory whenever count > 0 (a dump always warrants a look).

Tests

14 new cases in Dashboard.Tests (the shared-library home for the WS3 analogues): scoring (bad → 0.4, fine → 0), rooting (each roots a standalone finding below 0.5, mirroring ServerConfigFact_RootsStandalone_BelowMinimumSeverity), and advice presence.

• Dashboard.Tests: 420 → 434 (all pass)
• Lite.Tests: 362 → 362 (unchanged — no regression)
• Both apps build clean (0 Error(s), 0 Warning(s) from the changed code).

Not verified live

No run against a live SQL Server, so the actual DMV reads and the upgrade ALTER are unverified on a real instance. Version-gating: IFI guarded on DMV + column existence (+ dynamic SQL); dumps guarded on DMV existence; both skipped on Azure SQL DB (engine edition 5); LPIM left NULL on Azure. Reviewer to run the install + upgrade test.

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