feature: Observability: Prometheus Metrics and Grafana

This commit is contained in:
voltsrage
2026-06-17 16:25:27 +08:00
parent 101040f9d9
commit df99bf3c91
22 changed files with 1462 additions and 132 deletions
@@ -1,5 +1,7 @@
using System.Text.Json;
using Microsoft.EntityFrameworkCore;
using Prometheus;
using Serilog.Context;
using StackExchange.Redis;
public class ObservationService : IObservationService
@@ -7,15 +9,18 @@ public class ObservationService : IObservationService
private readonly AppDbContext _db;
private readonly IConnectionMultiplexer _redis;
private readonly ILogger<ObservationService> _logger;
private readonly ClinicalMetrics _metrics;
public ObservationService(
AppDbContext db,
IConnectionMultiplexer redis,
ILogger<ObservationService> logger)
ILogger<ObservationService> logger,
ClinicalMetrics metrics)
{
_db = db;
_redis = redis;
_logger = logger;
_metrics = metrics;
}
public async Task<IngestResult> IngestAsync(Guid encounterId, IngestObservationRequest req)
@@ -56,114 +61,133 @@ public class ObservationService : IObservationService
if (!PlausibilityValidator.IsPlausible(req.ObservationCode, req.Value, out var reason))
throw new ValidationException(reason!, "OBSERVATION_OUT_OF_PLAUSIBLE_RANGE");
// Steps 48 are one atomic transaction
await using var tx = await _db.Database.BeginTransactionAsync();
try
using (LogContext.PushProperty("EncounterId", encounterId))
using (LogContext.PushProperty("PatientId", encounter.PatientId))
{
// Step 4 — insert observation
var observation = new Observation
using var timer = _metrics.ObservationIngestDuration.NewTimer();
await using var tx = await _db.Database.BeginTransactionAsync();
try
{
Id = Guid.NewGuid(),
EncounterId = encounterId,
ObservationCode = req.ObservationCode,
Value = req.Value,
Unit = req.Unit,
Source = req.Source,
IdempotencyKey = req.IdempotencyKey,
RecordedAt = req.RecordedAt,
CreatedAt = DateTimeOffset.UtcNow
};
_db.Observations.Add(observation);
// Step 5 — load threshold from Redis; fall back to PostgreSQL on miss
var threshold = await LoadThresholdAsync(req.ObservationCode);
if (threshold is null)
throw new ValidationException(
$"No alert threshold is configured for observation code '{req.ObservationCode}'. " +
"Register a threshold before recording observations for this code.",
"UNKNOWN_OBSERVATION_CODE");
ClinicalAlert? alert = null;
// Step 6 — critical threshold detection (synchronous)
// WARNING detection is intentionally deferred to the Kafka consumer.
// A critical potassium of 2.1 mEq/L is immediately life-threatening — the alert
// must exist before this API call returns. A warning heart rate of 95 bpm warrants
// attention but not an emergency page; the additional Kafka latency is clinically safe.
if (IsCriticalBreach(req.Value, threshold))
{
alert = new ClinicalAlert
// Step 4 — insert observation
var observation = new Observation
{
Id = Guid.NewGuid(),
EncounterId = encounterId,
PatientId = encounter.PatientId,
ObservationId = observation.Id,
AlertType = AlertTypeExtensions.CriticalFor(req.ObservationCode),
Severity = AlertSeverity.Critical,
Details = BuildCriticalDetails(req, threshold),
Status = AlertStatus.Open,
TriggeredAt = DateTimeOffset.UtcNow
ObservationCode = req.ObservationCode,
Value = req.Value,
Unit = req.Unit,
Source = req.Source,
IdempotencyKey = req.IdempotencyKey,
RecordedAt = req.RecordedAt,
CreatedAt = DateTimeOffset.UtcNow
};
_db.ClinicalAlerts.Add(alert);
_db.Observations.Add(observation);
// Step 6boutbox event for the alert (relay picks this up in Phase 3)
_db.OutboxEvents.Add(BuildOutboxEvent("alert.generated", new
// Step 5load threshold from Redis; fall back to PostgreSQL on miss
var threshold = await LoadThresholdAsync(req.ObservationCode);
if (threshold is null)
throw new ValidationException(
$"No alert threshold is configured for observation code '{req.ObservationCode}'. " +
"Register a threshold before recording observations for this code.",
"UNKNOWN_OBSERVATION_CODE");
ClinicalAlert? alert = null;
// Step 6 — critical threshold detection (synchronous)
// WARNING detection is intentionally deferred to the Kafka consumer.
// A critical potassium of 2.1 mEq/L is immediately life-threatening — the alert
// must exist before this API call returns. A warning heart rate of 95 bpm warrants
// attention but not an emergency page; the additional Kafka latency is clinically safe.
if (IsCriticalBreach(req.Value, threshold))
{
alertId = alert.Id,
alert = new ClinicalAlert
{
Id = Guid.NewGuid(),
EncounterId = encounterId,
PatientId = encounter.PatientId,
ObservationId = observation.Id,
AlertType = AlertTypeExtensions.CriticalFor(req.ObservationCode),
Severity = AlertSeverity.Critical,
Details = BuildCriticalDetails(req, threshold),
Status = AlertStatus.Open,
TriggeredAt = DateTimeOffset.UtcNow
};
_db.ClinicalAlerts.Add(alert);
// Step 6b — outbox event for the alert (relay picks this up in Phase 3)
_db.OutboxEvents.Add(BuildOutboxEvent("alert.generated", new
{
alertId = alert.Id,
encounterId,
patientId = encounter.PatientId,
department = encounter.Department.ToDbString(),
alertType = alert.AlertType.ToDbString(),
severity = alert.Severity.ToDbString(),
details = alert.Details,
attendingPhysician = encounter.AttendingPhysician,
triggeredAt = alert.TriggeredAt,
partitionKey = encounterId.ToString()
}, encounterId.ToString()));
}
// Step 7 — outbox event for the observation (always; Kafka consumer handles warnings)
_db.OutboxEvents.Add(BuildOutboxEvent("observation.recorded", new
{
observationId = observation.Id,
encounterId,
patientId = encounter.PatientId,
department = encounter.Department.ToDbString(),
alertType = alert.AlertType.ToDbString(),
severity = alert.Severity.ToDbString(),
details = alert.Details,
attendingPhysician = encounter.AttendingPhysician,
triggeredAt = alert.TriggeredAt,
mrn = encounter.Patient?.Mrn,
observationCode = req.ObservationCode,
value = req.Value,
unit = req.Unit,
source = req.Source.ToDbString(),
recordedAt = req.RecordedAt,
partitionKey = encounterId.ToString()
}, encounterId.ToString()));
// Step 8 — COMMIT
await _db.SaveChangesAsync();
await tx.CommitAsync();
_metrics.ObservationsIngestedTotal
.WithLabels(req.ObservationCode, req.Source.ToDbString())
.Inc();
if (alert is not null)
{
_metrics.ClinicalAlertsTotal
.WithLabels(alert.AlertType.ToDbString(), alert.Severity.ToDbString())
.Inc();
_logger.LogWarning(
"Critical threshold breach. Code={Code} Value={Value} AlertId={AlertId}",
req.ObservationCode, req.Value, alert.Id);
}
_logger.LogInformation(
"Observation {ObservationId} ingested for encounter {EncounterId}. AlertCreated={AlertCreated}",
observation.Id, encounterId, alert is not null);
return IngestResult.Created(observation, alert);
}
// Step 7 — outbox event for the observation (always; Kafka consumer handles warnings)
_db.OutboxEvents.Add(BuildOutboxEvent("observation.recorded", new
catch (DbUpdateException ex) when (IsUniqueViolation(ex))
{
observationId = observation.Id,
encounterId,
patientId = encounter.PatientId,
mrn = encounter.Patient?.Mrn,
observationCode = req.ObservationCode,
value = req.Value,
unit = req.Unit,
source = req.Source.ToDbString(),
recordedAt = req.RecordedAt,
partitionKey = encounterId.ToString()
}, encounterId.ToString()));
// Step 8 — COMMIT
await _db.SaveChangesAsync();
await tx.CommitAsync();
_logger.LogInformation(
"Observation {ObservationId} ingested for encounter {EncounterId}. AlertCreated={AlertCreated}",
observation.Id, encounterId, alert is not null);
return IngestResult.Created(observation, alert);
}
catch (DbUpdateException ex) when (IsUniqueViolation(ex))
{
// Race condition: two concurrent retries both passed the pre-check above.
// The unique partial index caught it. Roll back and return the existing row.
await tx.RollbackAsync();
var existing = await _db.Observations
.AsNoTracking()
.FirstOrDefaultAsync(o => o.IdempotencyKey == req.IdempotencyKey);
if (existing is not null)
return IngestResult.Duplicate(existing);
throw new ConflictException("Concurrent duplicate submission.", "CONCURRENT_DUPLICATE");
}
catch
{
await tx.RollbackAsync();
throw;
// Race condition: two concurrent retries both passed the pre-check above.
// The unique partial index caught it. Roll back and return the existing row.
await tx.RollbackAsync();
var existing = await _db.Observations
.AsNoTracking()
.FirstOrDefaultAsync(o => o.IdempotencyKey == req.IdempotencyKey);
if (existing is not null)
return IngestResult.Duplicate(existing);
throw new ConflictException("Concurrent duplicate submission.", "CONCURRENT_DUPLICATE");
}
catch
{
await tx.RollbackAsync();
throw;
}
}
}