apache · janhoy · Mar 17, 2026 · Mar 17, 2026 · Mar 17, 2026 · Mar 19, 2026
diff --git a/changelog/unreleased/SOLR-18165-dot-separated-metric-names.yml b/changelog/unreleased/SOLR-18165-dot-separated-metric-names.yml
@@ -0,0 +1,8 @@
+title: Use dot-separated OTel metric names for OTLP export. This is a back-compat break from version 10.0
+type: changed
+authors:
+  - name: Jan Høydahl
+    url: https://home.apache.org/phonebook.html?uid=janhoy
+links:
+  - name: SOLR-18165
+    url: https://issues.apache.org/jira/browse/SOLR-18165
diff --git a/solr/core/src/java/org/apache/solr/core/CoreContainer.java b/solr/core/src/java/org/apache/solr/core/CoreContainer.java
@@ -809,7 +809,7 @@ private void loadInternal() {
           caffeineCache.initializeMetrics(
               solrMetricsContext,
               Attributes.builder().put(NAME_ATTR, cacheName).build(),
-              "solr_node_cache");
+              "solr.node.cache");
         }
         m.put(cacheName, c);
       }
@@ -952,7 +952,7 @@ private void loadInternal() {
             ExecutorUtil.newMDCAwareFixedThreadPool(
                 cfg.getCoreLoadThreadCount(isZooKeeperAware()),
                 new SolrNamedThreadFactory("coreLoadExecutor")),
-            "solr_node_executor",
+            "solr.node.executor",
             "coreLoadExecutor",
             SolrInfoBean.Category.CONTAINER);
 

diff --git a/solr/core/src/java/org/apache/solr/core/SolrCore.java b/solr/core/src/java/org/apache/solr/core/SolrCore.java
@@ -254,7 +254,12 @@ public class SolrCore implements SolrInfoBean, Closeable {
   private AttributedLongCounter newSearcherMaxReachedCounter;
   private AttributedLongCounter newSearcherOtherErrorsCounter;
   private AttributedLongTimer newSearcherTimer;
+
+  @Deprecated(
+      since = "10.1",
+      forRemoval = true) // Duplicate of solr.core.indexsearcher.warmup_time - remove
   private AttributedLongTimer newSearcherWarmupTimer;
+
   private List<AutoCloseable> toClose;
 
   private final String metricTag = SolrMetricProducer.getUniqueMetricTag(this, null);
@@ -1340,49 +1345,49 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
     newSearcherCounter =
         new AttributedLongCounter(
             parentContext.longCounter(
-                "solr_core_searcher_new", "Total number of new searchers opened"),
+                "solr.core.searcher.new", "Total number of new searchers opened"),
             baseSearcherAttributes);
 
     newSearcherMaxReachedCounter =
         new AttributedLongCounter(
             parentContext.longCounter(
-                "solr_core_searcher_warming_max",
+                "solr.core.searcher.warming_max",
                 "Total number of maximum concurrent warming searchers reached"),
             baseSearcherAttributes);
 
     newSearcherOtherErrorsCounter =
         new AttributedLongCounter(
             parentContext.longCounter(
-                "solr_core_searcher_errors", "Total number of searcher errors"),
+                "solr.core.searcher.errors", "Total number of searcher errors"),
             baseSearcherAttributes);
 
     newSearcherTimer =
         new AttributedLongTimer(
             parentContext.longHistogram(
-                "solr_core_indexsearcher_open_time",
+                "solr.core.indexsearcher.open.time",
                 "Time to open new searchers",
                 OtelUnit.MILLISECONDS),
             baseSearcherAttributes);
 
     newSearcherWarmupTimer =
         new AttributedLongTimer(
             parentContext.longHistogram(
-                "solr_core_indexsearcher_open_warmup_time",
-                "Time to warmup new searchers",
+                "solr.core.indexsearcher.open.warmup_time",
+                "DEPRECATED - Use solr.core.indexsearcher.warmup_time instead",
                 OtelUnit.MILLISECONDS),
             baseSearcherAttributes);
 
     observables.add(
         parentContext.observableLongGauge(
-            "solr_core_ref_count",
+            "solr.core.ref_count",
             "The current number of active references to a Solr core",
             (observableLongMeasurement -> {
               observableLongMeasurement.record(getOpenCount(), baseGaugeCoreAttributes);
             })));
 
     observables.add(
         parentContext.observableDoubleGauge(
-            "solr_core_disk_space",
+            "solr.core.disk_space",
             "Solr core disk space metrics",
             (observableDoubleMeasurement -> {
 
@@ -1417,7 +1422,7 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
 
     observables.add(
         parentContext.observableDoubleGauge(
-            "solr_core_index_size",
+            "solr.core.index.size",
             "Index size for a Solr core",
             (observableDoubleMeasurement -> {
               if (!isClosed())
@@ -1427,7 +1432,7 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
             OtelUnit.MEGABYTES));
 
     parentContext.observableLongGauge(
-        "solr_core_segments",
+        "solr.core.segments",
         "Number of segments in a Solr core",
         (observableLongMeasurement -> {
           if (isReady())
@@ -1437,7 +1442,7 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
     if (coreContainer.isZooKeeperAware())
       observables.add(
           parentContext.observableLongGauge(
-              "solr_core_is_leader",
+              "solr.core.is_leader",
               "Indicates whether this Solr core is currently the leader",
               (observableLongMeasurement -> {
                 observableLongMeasurement.record(

diff --git a/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java b/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java
@@ -882,55 +882,55 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
 
     ObservableDoubleMeasurement indexSizeMetric =
         solrMetricsContext.doubleGaugeMeasurement(
-            "solr_core_replication_index_size",
+            "solr.core.replication.index.size",
             "Size of the index in megabytes",
             OtelUnit.MEGABYTES);
 
     ObservableLongMeasurement indexVersionMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_index_version", "Current index version");
+            "solr.core.replication.index.version", "Current index version");
 
     ObservableLongMeasurement indexGenerationMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_index_generation", "Current index generation");
+            "solr.core.replication.index.generation", "Current index generation");
 
     ObservableLongMeasurement isLeaderMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_is_leader", "Whether this node is a leader (1) or not (0)");
+            "solr.core.replication.is_leader", "Whether this node is a leader (1) or not (0)");
 
     ObservableLongMeasurement isFollowerMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_is_follower", "Whether this node is a follower (1) or not (0)");
+            "solr.core.replication.is_follower", "Whether this node is a follower (1) or not (0)");
 
     ObservableLongMeasurement replicationEnabledMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_is_enabled", "Whether replication is enabled (1) or not (0)");
+            "solr.core.replication.is_enabled", "Whether replication is enabled (1) or not (0)");
 
     ObservableLongMeasurement isPollingDisabledMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_is_polling_disabled",
+            "solr.core.replication.is_polling_disabled",
             "Whether polling is disabled (1) or not (0)");
 
     ObservableLongMeasurement isReplicatingMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_is_replicating",
+            "solr.core.replication.is_replicating",
             "Whether replication is in progress (1) or not (0)");
 
     ObservableLongMeasurement timeElapsedMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_time_elapsed",
+            "solr.core.replication.time_elapsed",
             "Time elapsed during replication in seconds",
             OtelUnit.SECONDS);
 
     ObservableLongMeasurement bytesDownloadedMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_downloaded_size",
+            "solr.core.replication.downloaded_size",
             "Total bytes downloaded during replication",
             OtelUnit.BYTES);
 
     ObservableLongMeasurement downloadSpeedMetric =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_replication_download_speed", "Download speed in bytes per second");
+            "solr.core.replication.download_speed", "Download speed in bytes per second");
 
     metricsCallback =
         solrMetricsContext.batchCallback(

diff --git a/solr/core/src/java/org/apache/solr/handler/RequestHandlerBase.java b/solr/core/src/java/org/apache/solr/handler/RequestHandlerBase.java
@@ -198,27 +198,27 @@ public HandlerMetrics(
 
       requests =
           factory.attributedLongCounter(
-              "solr_core_requests", "HTTP Solr requests", Attributes.empty());
+              "solr.core.requests", "HTTP Solr requests", Attributes.empty());
 
       numServerErrors =
           factory.attributedLongCounter(
-              "solr_core_requests_errors",
+              "solr.core.requests.errors",
               "HTTP Solr request errors",
               Attributes.of(SOURCE_ATTR, "server"));
 
       numClientErrors =
           factory.attributedLongCounter(
-              "solr_core_requests_errors",
+              "solr.core.requests.errors",
               "HTTP Solr request errors",
               Attributes.of(SOURCE_ATTR, "client"));
 
       numTimeouts =
           factory.attributedLongCounter(
-              "solr_core_requests_timeout", "HTTP Solr request timeouts", Attributes.empty());
+              "solr.core.requests.timeout", "HTTP Solr request timeouts", Attributes.empty());
 
       requestTimes =
           factory.attributedLongTimer(
-              "solr_core_requests_times",
+              "solr.core.requests.times",
               "HTTP Solr request times",
               OtelUnit.MILLISECONDS,
               Attributes.empty());

diff --git a/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java b/solr/core/src/java/org/apache/solr/handler/admin/CoreAdminHandler.java
@@ -132,14 +132,14 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
     coreAdminAsyncTracker.standardExecutor =
         solrMetricsContext.instrumentedExecutorService(
             coreAdminAsyncTracker.standardExecutor,
-            "solr_node_executor",
+            "solr.node.executor",
             "asyncCoreAdminExecutor",
             getCategory());
 
     coreAdminAsyncTracker.expensiveExecutor =
         solrMetricsContext.instrumentedExecutorService(
             coreAdminAsyncTracker.expensiveExecutor,
-            "solr_node_executor",
+            "solr.node.executor",
             "asyncCoreExpensiveAdminExecutor",
             getCategory());
   }

diff --git a/solr/core/src/java/org/apache/solr/handler/component/HttpShardHandlerFactory.java b/solr/core/src/java/org/apache/solr/handler/component/HttpShardHandlerFactory.java
@@ -439,6 +439,6 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
     httpListenerFactory.initializeMetrics(solrMetricsContext, Attributes.empty());
     commExecutor =
         solrMetricsContext.instrumentedExecutorService(
-            commExecutor, "solr_core_executor", "httpShardExecutor", SolrInfoBean.Category.QUERY);
+            commExecutor, "solr.core.executor", "httpShardExecutor", SolrInfoBean.Category.QUERY);
   }
 }
diff --git a/solr/core/src/java/org/apache/solr/handler/component/SuggestComponent.java b/solr/core/src/java/org/apache/solr/handler/component/SuggestComponent.java
@@ -392,7 +392,7 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
         attributes.toBuilder().put(CATEGORY_ATTR, getCategory().toString()).build();
     this.toClose =
         this.solrMetricsContext.observableLongGauge(
-            "solr_core_suggester_total_size",
+            "solr.core.suggester.total.size",
             "Total memory size in bytes of all suggester",
             (observableLongMeasurement) -> {
               observableLongMeasurement.record(ramBytesUsed(), suggesterAttributes);

diff --git a/solr/core/src/java/org/apache/solr/metrics/otel/FilterablePrometheusMetricReader.java b/solr/core/src/java/org/apache/solr/metrics/otel/FilterablePrometheusMetricReader.java
@@ -65,8 +65,9 @@ public MetricSnapshots collect(
       return super.collect();
     }
 
-    // Prometheus appends a suffix to the metrics depending on the metric type. We need to sanitize
-    // the suffix off if they filter by Prometheus name instead of OTEL name.
+    // Users may filter by Prometheus-format names (e.g. "solr_core_requests") or with a
+    // Prometheus type suffix (e.g. "solr_core_requests_total"). Strip any such suffix so we can
+    // compare against the Prometheus base name returned by getMetadata().getPrometheusName().
     Set<String> sanitizedNames =
         includedNames.stream()
             .map(
@@ -84,7 +85,18 @@ public MetricSnapshots collect(
     if (sanitizedNames.isEmpty()) {
       snapshotsToFilter = super.collect();
     } else {
-      snapshotsToFilter = super.collect(sanitizedNames::contains);
+      // We collect all metrics and filter by Prometheus name rather than using
+      // super.collect(Predicate) which matches on OTel internal names. This avoids a mismatch
+      // when OTel names use dot-separators (e.g. "solr.core.requests") but users filter by the
+      // Prometheus underscore-format name they see in the output (e.g. "solr_core_requests").
+      MetricSnapshots all = super.collect();
+      MetricSnapshots.Builder nameFiltered = MetricSnapshots.builder();
+      for (MetricSnapshot snapshot : all) {
+        if (sanitizedNames.contains(snapshot.getMetadata().getPrometheusName())) {
+          nameFiltered.metricSnapshot(snapshot);
+        }
+      }
+      snapshotsToFilter = nameFiltered.build();
     }
 
     // Return named filtered snapshots if not label filters provided

diff --git a/solr/core/src/java/org/apache/solr/metrics/otel/instruments/AttributedInstrumentFactory.java b/solr/core/src/java/org/apache/solr/metrics/otel/instruments/AttributedInstrumentFactory.java
@@ -132,7 +132,7 @@ public AttributedLongTimer attributedLongTimer(
 
   /** Replace core metric name prefix to node prefix */
   private String toNodeMetricName(String coreMetricName) {
-    return coreMetricName.replace("solr_core", "solr_node");
+    return coreMetricName.replace("solr.core", "solr.node");
   }
 
   /** Filter out core attributes and keep all others for node-level metrics */

diff --git a/solr/core/src/java/org/apache/solr/search/SolrFieldCacheBean.java b/solr/core/src/java/org/apache/solr/search/SolrFieldCacheBean.java
@@ -60,10 +60,10 @@ public void initializeMetrics(SolrMetricsContext parentContext, Attributes attri
     this.solrMetricsContext = parentContext;
     var solrCacheStats =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_field_cache_entries", "Number of field cache entries");
+            "solr.core.field_cache.entries", "Number of field cache entries");
     var solrCacheSize =
         solrMetricsContext.longGaugeMeasurement(
-            "solr_core_field_cache_size", "Size of field cache in bytes", OtelUnit.BYTES);
+            "solr.core.field_cache.size", "Size of field cache in bytes", OtelUnit.BYTES);
     this.toClose =
         solrMetricsContext.batchCallback(
             () -> {

diff --git a/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java b/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java
@@ -612,7 +612,7 @@ public void register() {
         caffeineCache.initializeMetrics(
             solrMetricsContext,
             core.getCoreAttributes().toBuilder().put(NAME_ATTR, cache.name()).build(),
-            "solr_core_indexsearcher_cache");
+            "solr.core.indexsearcher.cache");
       }
     }
     initializeMetrics(solrMetricsContext, core.getCoreAttributes());
@@ -2637,14 +2637,14 @@ public void initializeMetrics(SolrMetricsContext solrMetricsContext, Attributes
     warmupTimer =
         new AttributedLongTimer(
             solrMetricsContext.longHistogram(
-                "solr_core_indexsearcher_warmup_time",
+                "solr.core.indexsearcher.warmup_time",
                 "Searcher warmup time (ms)",
                 OtelUnit.MILLISECONDS),
             baseAttributes);
 
     toClose.add(
         solrMetricsContext.observableLongCounter(
-            "solr_core_indexsearcher_live_docs_cache",
+            "solr.core.indexsearcher.live_docs.cache",
             "LiveDocs cache metrics",
             obs -> {
               obs.record(
@@ -2660,7 +2660,7 @@ public void initializeMetrics(SolrMetricsContext solrMetricsContext, Attributes
     // reader stats (numeric)
     toClose.add(
         solrMetricsContext.observableLongGauge(
-            "solr_core_indexsearcher_index_num_docs",
+            "solr.core.indexsearcher.index.num_docs",
             "Number of live docs in the index",
             obs -> {
               try {
@@ -2672,7 +2672,7 @@ public void initializeMetrics(SolrMetricsContext solrMetricsContext, Attributes
 
     toClose.add(
         solrMetricsContext.observableLongGauge(
-            "solr_core_indexsearcher_index_docs",
+            "solr.core.indexsearcher.index.docs",
             "Total number of docs in the index (including deletions)",
             obs -> {
               try {
@@ -2683,7 +2683,7 @@ public void initializeMetrics(SolrMetricsContext solrMetricsContext, Attributes
     // indexVersion (numeric)
     toClose.add(
         solrMetricsContext.observableLongGauge(
-            "solr_core_indexsearcher_index_version",
+            "solr.core.indexsearcher.index.version",
             "Lucene index version",
             obs -> {
               try {
@@ -2694,7 +2694,7 @@ public void initializeMetrics(SolrMetricsContext solrMetricsContext, Attributes
     // size of the currently opened commit
     toClose.add(
         solrMetricsContext.observableDoubleGauge(
-            "solr_core_indexsearcher_index_commit_size",
+            "solr.core.indexsearcher.index.commit_size",
             "Size of the current index commit (megabytes)",
             obs -> {
               try {

diff --git a/solr/core/src/java/org/apache/solr/search/stats/StatsCache.java b/solr/core/src/java/org/apache/solr/search/stats/StatsCache.java
@@ -336,7 +336,7 @@ public void initializeMetrics(SolrMetricsContext solrMetricsContext, Attributes
             .build();
     this.toClose =
         solrMetricsContext.observableLongGauge(
-            "solr_core_indexsearcher_termstats_cache",
+            "solr.core.indexsearcher.termstats.cache",
             "Operation counts for the searcher term statistics cache, reported per operation type",
             obs -> {
               var cacheMetrics = getCacheMetrics();