Register prometheus counters correctly.

Commit f081419e68 moved all the prometheus counters to `metrics.rs`,
but accidentally replaced a couple of `register_int_counter!(...)`
calls with just `IntCounter::new(...)`. Because of that, the counters
were not registered in the metrics registry, and were not exposed
through the metrics HTTP endpoint.

Fixes failures we're seeing in a bunch of 'performance' tests because
of the missing metrics.

pageserver/src/metrics.rs

@@ -107,7 +107,7 @@ static CURRENT_LOGICAL_SIZE: Lazy<UIntGaugeVec> = Lazy::new(|| {
 // Metrics for cloud upload. These metrics reflect data uploaded to cloud storage,
 // or in testing they estimate how much we would upload if we did.
 static NUM_PERSISTENT_FILES_CREATED: Lazy<IntCounter> = Lazy::new(|| {
-    IntCounter::new(
+    register_int_counter!(
         "pageserver_created_persistent_files_total",
         "Number of files created that are meant to be uploaded to cloud storage",
     )
@@ -115,7 +115,7 @@ static NUM_PERSISTENT_FILES_CREATED: Lazy<IntCounter> = Lazy::new(|| {
 });
 
 static PERSISTENT_BYTES_WRITTEN: Lazy<IntCounter> = Lazy::new(|| {
-    IntCounter::new(
+    register_int_counter!(
         "pageserver_written_persistent_bytes_total",
         "Total bytes written that are meant to be uploaded to cloud storage",
     )

test_runner/fixtures/benchmark_fixture.py

@@ -362,7 +362,7 @@ class NeonBenchmarker:
         # and round to integer.
         all_metrics = pageserver.http_client().get_metrics()
         matches = re.search(rf"^{metric_name} (\S+)$", all_metrics, re.MULTILINE)
-        assert matches
+        assert matches, f"metric {metric_name} not found"
         return int(round(float(matches.group(1))))
 
     def get_timeline_size(self, repo_dir: Path, tenantid: ZTenantId, timelineid: ZTimelineId):