Register quota metrics unconditionally

Both quota gates in monitoringHandler tested config.isQuotaEnabled -- the
function reference rather than a call -- so both were always true and all six
quota metrics were always registered.

Drop the conditionals rather than calling the function. Always registering is
what has actually happened since these checks were written, nothing depends on
the metrics disappearing when quota is off, and gating registration would mean
guarding every metric touch point against a metric that was never created:
crrCacheToProm reached bucketsWithQuota unguarded, and the scuba wrapper
observes its histogram in a finally block, on a path the Veeam capacity route
hits with no quota gating at all.

Behaviour is unchanged -- the six s3_cloudserver_quota_* series are exposed
exactly as before -- so this is a dead code removal.

Issue: CLDSRV-972

Author: delthas

lib/utilities/monitoringHandler.js

@@ -65,48 +65,39 @@ const httpResponseSizeBytes = new client.Summary({
     help: 'Cloudserver HTTP response sizes in bytes',
 });
 
-let quotaEvaluationDuration;
-let utilizationMetricsRetrievalDuration;
-let utilizationServiceAvailable;
-let bucketsWithQuota;
-let accountsWithQuota;
-let requestWithQuotaMetricsUnavailable;
-
-if (config.isQuotaEnabled) {
-    quotaEvaluationDuration = new client.Histogram({
-        name: 's3_cloudserver_quota_evaluation_duration_seconds',
-        help: 'Duration of the quota evaluation operation',
-        labelNames: ['action', 'code', 'type'],
-        buckets: [0.001, 0.0025, 0.005, 0.01, 0.025, 0.05, 0.1, 0.2, 0.5, 1],
-    });
+const quotaEvaluationDuration = new client.Histogram({
+    name: 's3_cloudserver_quota_evaluation_duration_seconds',
+    help: 'Duration of the quota evaluation operation',
+    labelNames: ['action', 'code', 'type'],
+    buckets: [0.001, 0.0025, 0.005, 0.01, 0.025, 0.05, 0.1, 0.2, 0.5, 1],
+});
 
-    utilizationMetricsRetrievalDuration = new client.Histogram({
-        name: 's3_cloudserver_quota_metrics_retrieval_duration_seconds',
-        help: 'Duration of the utilization metrics retrieval operation',
-        labelNames: ['code', 'class'],
-        buckets: [0.001, 0.0025, 0.005, 0.01, 0.025, 0.05, 0.1, 0.2, 0.5],
-    });
+const utilizationMetricsRetrievalDuration = new client.Histogram({
+    name: 's3_cloudserver_quota_metrics_retrieval_duration_seconds',
+    help: 'Duration of the utilization metrics retrieval operation',
+    labelNames: ['code', 'class'],
+    buckets: [0.001, 0.0025, 0.005, 0.01, 0.025, 0.05, 0.1, 0.2, 0.5],
+});
 
-    utilizationServiceAvailable = new client.Gauge({
-        name: 's3_cloudserver_quota_utilization_service_available',
-        help: 'Availability of the utilization service',
-    });
+const utilizationServiceAvailable = new client.Gauge({
+    name: 's3_cloudserver_quota_utilization_service_available',
+    help: 'Availability of the utilization service',
+});
 
-    bucketsWithQuota = new client.Gauge({
-        name: 's3_cloudserver_quota_buckets_count',
-        help: 'Total number of buckets quota',
-    });
+const bucketsWithQuota = new client.Gauge({
+    name: 's3_cloudserver_quota_buckets_count',
+    help: 'Total number of buckets quota',
+});
 
-    accountsWithQuota = new client.Gauge({
-        name: 's3_cloudserver_quota_accounts_count',
-        help: 'Total number of account quota',
-    });
+const accountsWithQuota = new client.Gauge({
+    name: 's3_cloudserver_quota_accounts_count',
+    help: 'Total number of account quota',
+});
 
-    requestWithQuotaMetricsUnavailable = new client.Counter({
-        name: 's3_cloudserver_quota_unavailable_count',
-        help: 'Total number of requests with quota metrics unavailable',
-    });
-}
+const requestWithQuotaMetricsUnavailable = new client.Counter({
+    name: 's3_cloudserver_quota_unavailable_count',
+    help: 'Total number of requests with quota metrics unavailable',
+});
 
 // Lifecycle duration metric, to track the completion of restore.
 // This metric is used to track the time it takes to complete the lifecycle operation (restore).
@@ -189,10 +180,10 @@ function crrCacheToProm(crrResults) {
         if (crrResults.getObjectCount) {
             numberOfBuckets.set(crrResults.getObjectCount.buckets || 0);
             numberOfObjects.set(crrResults.getObjectCount.objects || 0);
+            bucketsWithQuota.set(crrResults.getObjectCount.bucketWithQuotaCount || 0);
         }
-        if (config.isQuotaEnabled) {
-            bucketsWithQuota.set(crrResults?.getObjectCount?.bucketWithQuotaCount || 0);
-            accountsWithQuota.set(crrResults?.getVaultReport?.accountWithQuotaCount || 0);
+        if (crrResults.getVaultReport) {
+            accountsWithQuota.set(crrResults.getVaultReport.accountWithQuotaCount || 0);
         }
         if (crrResults.getDataDiskUsage) {
             dataDiskAvailable.set(crrResults.getDataDiskUsage.available || 0);

tests/unit/utils/monitoring.js

@@ -3,6 +3,7 @@ const promclient = require('prom-client');
 const sinon = require('sinon');
 
 const monitoring = require('../../../lib/utilities/monitoringHandler');
+const { config } = require('../../../lib/Config');
 
 describe('Monitoring: endpoint', () => {
     const sandbox = sinon.createSandbox();
@@ -139,4 +140,35 @@ describe('Monitoring: endpoint', () => {
         await fetchMetrics({ method: 'GET', url: '/metrics' }, res);
         assert(parseHttpResponseSize(res.end.args[1][0]) === responseSize + 7532);
     });
+
+    const quotaMetricNames = [
+        's3_cloudserver_quota_evaluation_duration_seconds',
+        's3_cloudserver_quota_metrics_retrieval_duration_seconds',
+        's3_cloudserver_quota_utilization_service_available',
+        's3_cloudserver_quota_buckets_count',
+        's3_cloudserver_quota_accounts_count',
+        's3_cloudserver_quota_unavailable_count',
+    ];
+
+    it('should register quota metrics even when quota is disabled', async () => {
+        assert.strictEqual(config.isQuotaEnabled(), false);
+
+        await fetchMetrics({ method: 'GET', url: '/metrics' }, res);
+        const metrics = res.end.args[0][0];
+
+        quotaMetricNames.forEach(name => assert(metrics.includes(name), `${name} is not registered`));
+    });
+
+    it('should report the quota counts from crrCacheToProm', async () => {
+        monitoring.crrCacheToProm({
+            getObjectCount: { buckets: 1, objects: 2, bucketWithQuotaCount: 3 },
+            getVaultReport: { accountWithQuotaCount: 4 },
+        });
+
+        await fetchMetrics({ method: 'GET', url: '/metrics' }, res);
+        const metrics = res.end.args[0][0];
+
+        assert(metrics.includes('\ns3_cloudserver_quota_buckets_count 3'));
+        assert(metrics.includes('\ns3_cloudserver_quota_accounts_count 4'));
+    });
 });