#1806 Provide configurable search count metrics to be exposed via Prometheus

.github/workflows/helm-chart.yml

@@ -65,7 +65,7 @@ jobs:
         k8s:
           - v1.26.6
           - v1.27.3
-          - v1.28.3
+          - v1.28.0
     steps:
       - name: Checkout
         uses: actions/checkout@v4

base/model/src/main/java/org/eclipse/ditto/base/model/common/DittoSystemProperties.java

@@ -39,6 +39,11 @@ public final class DittoSystemProperties {
      */
     public static final String DITTO_LIMITS_POLICY_IMPORTS_LIMIT = "ditto.limits.policy.imports-limit";
 
+    /**
+     * System property name of the property defining a common prefix for all metrics Ditto reports via Prometheus.
+     */
+    public static final String DITTO_METRICS_METRIC_PREFIX = "ditto.metrics.metric-prefix";
+
     private DittoSystemProperties() {
         throw new AssertionError();
     }

base/service/src/main/java/org/eclipse/ditto/base/service/DittoService.java

@@ -24,6 +24,17 @@
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+import org.apache.pekko.Done;
+import org.apache.pekko.actor.ActorRef;
+import org.apache.pekko.actor.ActorSystem;
+import org.apache.pekko.actor.CoordinatedShutdown;
+import org.apache.pekko.actor.Props;
+import org.apache.pekko.cluster.Cluster;
+import org.apache.pekko.cluster.pubsub.DistributedPubSub;
+import org.apache.pekko.http.javadsl.Http;
+import org.apache.pekko.http.javadsl.model.Uri;
+import org.apache.pekko.management.cluster.bootstrap.ClusterBootstrap;
+import org.apache.pekko.management.javadsl.PekkoManagement;
 import org.eclipse.ditto.base.model.common.DittoSystemProperties;
 import org.eclipse.ditto.base.model.signals.FeatureToggle;
 import org.eclipse.ditto.base.service.config.ServiceSpecificConfig;
@@ -35,6 +46,7 @@
 import org.eclipse.ditto.internal.utils.config.ScopedConfig;
 import org.eclipse.ditto.internal.utils.config.raw.RawConfigSupplier;
 import org.eclipse.ditto.internal.utils.health.status.StatusSupplierActor;
+import org.eclipse.ditto.internal.utils.metrics.config.MetricsConfig;
 import org.eclipse.ditto.internal.utils.metrics.prometheus.PrometheusReporterRoute;
 import org.eclipse.ditto.internal.utils.tracing.DittoTracing;
 import org.slf4j.Logger;
@@ -47,17 +59,6 @@
 import com.typesafe.config.ConfigValue;
 import com.typesafe.config.ConfigValueFactory;
 
-import org.apache.pekko.Done;
-import org.apache.pekko.actor.ActorRef;
-import org.apache.pekko.actor.ActorSystem;
-import org.apache.pekko.actor.CoordinatedShutdown;
-import org.apache.pekko.actor.Props;
-import org.apache.pekko.cluster.Cluster;
-import org.apache.pekko.cluster.pubsub.DistributedPubSub;
-import org.apache.pekko.http.javadsl.Http;
-import org.apache.pekko.http.javadsl.model.Uri;
-import org.apache.pekko.management.cluster.bootstrap.ClusterBootstrap;
-import org.apache.pekko.management.javadsl.PekkoManagement;
 import ch.qos.logback.classic.LoggerContext;
 import kamon.Kamon;
 import kamon.prometheus.PrometheusReporter;
@@ -121,10 +122,6 @@ protected DittoService(final Logger logger, final String serviceName, final Stri
         this.rootActorName = argumentNotEmpty(rootActorName, "root actor name");
         rawConfig = determineRawConfig();
         serviceSpecificConfig = getServiceSpecificConfig(tryToGetDittoConfigOrEmpty(rawConfig));
-        if (null == serviceSpecificConfig) {
-            throw new DittoConfigError("The service specific config must not be null!");
-        }
-
         logger.debug("Using service specific config: <{}>.", serviceSpecificConfig);
     }
 
@@ -208,6 +205,7 @@ private static ScopedConfig getDittoConfigOrEmpty(final Config rawConfig) {
     private ActorSystem doStart() {
         logRuntimeParameters();
         final var actorSystemConfig = appendDittoInfo(appendPekkoPersistenceMongoUriToRawConfig());
+        injectSystemPropertiesLimits(serviceSpecificConfig);
         startKamon();
         final var actorSystem = createActorSystem(actorSystemConfig);
         initializeActorSystem(actorSystem);
@@ -390,8 +388,6 @@ private void startServiceRootActors(final ActorSystem actorSystem, final C servi
 
             final ActorRef pubSubMediator = getDistributedPubSubMediatorActor(actorSystem);
 
-            injectSystemPropertiesLimits(serviceSpecificConfig);
-
             startMainRootActor(actorSystem, getMainRootActorProps(serviceSpecificConfig, pubSubMediator));
             RootActorStarter.get(actorSystem, ScopedConfig.dittoExtension(actorSystem.settings().config())).execute();
         });
@@ -418,6 +414,8 @@ private void injectSystemPropertiesLimits(final C serviceSpecificConfig) {
                 Boolean.toString(rawConfig.getBoolean(FeatureToggle.MERGE_THINGS_ENABLED)));
         System.setProperty(DittoSystemProperties.DITTO_LIMITS_POLICY_IMPORTS_LIMIT,
                 Integer.toString(limitsConfig.getPolicyImportsLimit()));
+        final MetricsConfig metricsConfig = serviceSpecificConfig.getMetricsConfig();
+        System.setProperty(DittoSystemProperties.DITTO_METRICS_METRIC_PREFIX, metricsConfig.getMetricPrefix());
     }
 
     private static ActorRef getDistributedPubSubMediatorActor(final ActorSystem actorSystem) {

base/service/src/main/java/org/eclipse/ditto/base/service/config/limits/DefaultLimitsConfig.java

@@ -123,7 +123,7 @@ public int hashCode() {
     @Override
     public String toString() {
         return getClass().getSimpleName() + " [" +
-                ", thingsMaxSize=" + thingsMaxSize +
+                "thingsMaxSize=" + thingsMaxSize +
                 ", policiesMaxSize=" + policiesMaxSize +
                 ", messagesMaxSize=" + messagesMaxSize +
                 ", thingsSearchDefaultPageSize=" + thingsSearchDefaultPageSize +

deployment/helm/ditto/Chart.yaml

@@ -16,7 +16,7 @@ description: |
   A digital twin is a virtual, cloud based, representation of his real world counterpart
   (real world “Things”, e.g. devices like sensors, smart heating, connected cars, smart grids, EV charging stations etc).
 type: application
-version: 3.4.2  # chart version is effectively set by release-job
+version: 3.4.3  # chart version is effectively set by release-job
 appVersion: 3.4.1
 keywords:
   - iot-chart

deployment/helm/ditto/templates/connectivity-deployment.yaml

@@ -82,10 +82,14 @@ spec:
           env:
             {{- if not .Values.global.logging.customConfigFile.enabled }}
             - name: DITTO_LOGGING_DISABLE_SYSOUT_LOG
-              value: "{{ if .Values.global.logging.sysout.enabled }}false{{ else }}true{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.sysout.enabled }}"
             - name: DITTO_LOGGING_FILE_APPENDER
-              value: "{{ if .Values.global.logging.logFiles.enabled }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.logFiles.enabled }}"
             {{- end }}
+            - name: DITTO_METRICS_METRIC_PREFIX
+              value: "{{ .Values.global.metrics.metricsPrefix }}"
+            - name: SYSTEM_METRICS_ENABLED
+              value: "{{ .Values.global.metrics.systemMetrics.enabled }}"
             - name: DITTO_TRACING_ENABLED
               value: "{{ .Values.global.tracing.enabled }}"
             - name: DITTO_TRACING_OTEL_TRACE_REPORTER_ENABLED
@@ -137,7 +141,7 @@ spec:
                 {{- end }}
                 {{ join " " .Values.connectivity.systemProps }}
             - name: MONGO_DB_SSL_ENABLED
-              value: "{{ if .Values.dbconfig.connectivity.ssl }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.dbconfig.connectivity.ssl }}"
             - name: MONGO_DB_URI
               valueFrom:
                 secretKeyRef:

deployment/helm/ditto/templates/gateway-deployment.yaml

@@ -83,10 +83,14 @@ spec:
           env:
             {{- if not .Values.global.logging.customConfigFile.enabled }}
             - name: DITTO_LOGGING_DISABLE_SYSOUT_LOG
-              value: "{{ if .Values.global.logging.sysout.enabled }}false{{ else }}true{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.sysout.enabled }}"
             - name: DITTO_LOGGING_FILE_APPENDER
-              value: "{{ if .Values.global.logging.logFiles.enabled }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.logFiles.enabled }}"
             {{- end }}
+            - name: DITTO_METRICS_METRIC_PREFIX
+              value: "{{ .Values.global.metrics.metricsPrefix }}"
+            - name: SYSTEM_METRICS_ENABLED
+              value: "{{ .Values.global.metrics.systemMetrics.enabled }}"
             - name: DITTO_TRACING_ENABLED
               value: "{{ .Values.global.tracing.enabled }}"
             - name: DITTO_TRACING_OTEL_TRACE_REPORTER_ENABLED

deployment/helm/ditto/templates/policies-deployment.yaml

@@ -82,10 +82,14 @@ spec:
           env:
             {{- if not .Values.global.logging.customConfigFile.enabled }}
             - name: DITTO_LOGGING_DISABLE_SYSOUT_LOG
-              value: "{{ if .Values.global.logging.sysout.enabled }}false{{ else }}true{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.sysout.enabled }}"
             - name: DITTO_LOGGING_FILE_APPENDER
-              value: "{{ if .Values.global.logging.logFiles.enabled }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.logFiles.enabled }}"
             {{- end }}
+            - name: DITTO_METRICS_METRIC_PREFIX
+              value: "{{ .Values.global.metrics.metricsPrefix }}"
+            - name: SYSTEM_METRICS_ENABLED
+              value: "{{ .Values.global.metrics.systemMetrics.enabled }}"
             - name: DITTO_TRACING_ENABLED
               value: "{{ .Values.global.tracing.enabled }}"
             - name: DITTO_TRACING_OTEL_TRACE_REPORTER_ENABLED
@@ -155,7 +159,7 @@ spec:
                 {{- end }}
                 {{ join " " .Values.policies.systemProps }}
             - name: MONGO_DB_SSL_ENABLED
-              value: "{{ if .Values.dbconfig.policies.ssl }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.dbconfig.policies.ssl }}"
             - name: MONGO_DB_URI
               valueFrom:
                 secretKeyRef:

deployment/helm/ditto/templates/things-deployment.yaml

@@ -82,10 +82,14 @@ spec:
           env:
             {{- if not .Values.global.logging.customConfigFile.enabled }}
             - name: DITTO_LOGGING_DISABLE_SYSOUT_LOG
-              value: "{{ if .Values.global.logging.sysout.enabled }}false{{ else }}true{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.sysout.enabled }}"
             - name: DITTO_LOGGING_FILE_APPENDER
-              value: "{{ if .Values.global.logging.logFiles.enabled }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.logFiles.enabled }}"
             {{- end }}
+            - name: DITTO_METRICS_METRIC_PREFIX
+              value: "{{ .Values.global.metrics.metricsPrefix }}"
+            - name: SYSTEM_METRICS_ENABLED
+              value: "{{ .Values.global.metrics.systemMetrics.enabled }}"
             - name: DITTO_TRACING_ENABLED
               value: "{{ .Values.global.tracing.enabled }}"
             - name: DITTO_TRACING_OTEL_TRACE_REPORTER_ENABLED
@@ -156,7 +160,7 @@ spec:
                 '-Dditto.things.wot.to-thing-description.json-template={{ .Values.things.config.wot.tdJsonTemplate | replace "\n" "" | replace "\\\"" "\"" }}'
                 {{ join " " .Values.things.systemProps }}
             - name: MONGO_DB_SSL_ENABLED
-              value: "{{ if .Values.dbconfig.things.ssl }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.dbconfig.things.ssl }}"
             - name: MONGO_DB_URI
               valueFrom:
                 secretKeyRef:

deployment/helm/ditto/templates/thingssearch-deployment.yaml

@@ -82,10 +82,14 @@ spec:
           env:
             {{- if not .Values.global.logging.customConfigFile.enabled }}
             - name: DITTO_LOGGING_DISABLE_SYSOUT_LOG
-              value: "{{ if .Values.global.logging.sysout.enabled }}false{{ else }}true{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.sysout.enabled }}"
             - name: DITTO_LOGGING_FILE_APPENDER
-              value: "{{ if .Values.global.logging.logFiles.enabled }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.global.logging.logFiles.enabled }}"
             {{- end }}
+            - name: DITTO_METRICS_METRIC_PREFIX
+              value: "{{ .Values.global.metrics.metricsPrefix }}"
+            - name: SYSTEM_METRICS_ENABLED
+              value: "{{ .Values.global.metrics.systemMetrics.enabled }}"
             - name: DITTO_TRACING_ENABLED
               value: "{{ .Values.global.tracing.enabled }}"
             - name: DITTO_TRACING_OTEL_TRACE_REPORTER_ENABLED
@@ -132,9 +136,20 @@ spec:
                 {{- if .Values.global.logging.customConfigFile.enabled }}
                 -Dlogback.configurationFile=/opt/ditto/{{ .Values.global.logging.customConfigFile.fileName }}
                 {{- end }}
+                {{- range $key, $value := .Values.thingsSearch.config.operatorMetrics.customMetrics }}
+                "{{ printf "%s%s%s=%t" "-Dditto.search.operator-metrics.custom-metrics." $key ".enabled" $value.enabled }}"
+                "{{ printf "%s%s%s=%s" "-Dditto.search.operator-metrics.custom-metrics." $key ".scrape-interval" $value.scrapeInterval }}"
+                {{- range $index, $namespace := $value.namespaces }}
+                "{{ printf "%s%s%s%d=%s" "-Dditto.search.operator-metrics.custom-metrics." $key ".namespaces." $index $namespace }}"
+                {{- end }}
+                "{{ printf "%s%s%s=%s" "-Dditto.search.operator-metrics.custom-metrics." $key ".filter" $value.filter }}"
+                {{- range $tagKey, $tagValue := $value.tags }}
+                "{{ printf "%s%s%s%s=%s" "-Dditto.search.operator-metrics.custom-metrics." $key ".tags." $tagKey $tagValue }}"
+                {{- end }}
+                {{- end }}
                 {{ join " " .Values.thingsSearch.systemProps }}
             - name: MONGO_DB_SSL_ENABLED
-              value: "{{ if .Values.dbconfig.thingsSearch.ssl }}true{{ else }}false{{ end }}"
+              value: "{{ printf "%t" .Values.dbconfig.thingsSearch.ssl }}"
             - name: MONGO_DB_URI
               valueFrom:
                 secretKeyRef:
@@ -204,6 +219,10 @@ spec:
               value: "{{ .Values.thingsSearch.config.updater.stream.retrievalParallelism }}"
             - name: THINGS_SEARCH_UPDATER_STREAM_PERSISTENCE_PARALLELISM
               value: "{{ .Values.thingsSearch.config.updater.stream.persistence.parallelism }}"
+            - name: THINGS_SEARCH_OPERATOR_METRICS_ENABLED
+              value: "{{ .Values.thingsSearch.config.operatorMetrics.enabled }}"
+            - name: THINGS_SEARCH_OPERATOR_METRICS_SCRAPE_INTERVAL
+              value: "{{ .Values.thingsSearch.config.operatorMetrics.scrapeInterval }}"
             - name: ACTIVITY_CHECK_INTERVAL
               value: "{{ .Values.thingsSearch.config.updater.activityCheckInterval }}"
             - name: BACKGROUND_SYNC_ENABLED

deployment/helm/ditto/values.yaml

@@ -135,6 +135,14 @@ global:
       enabled: true
       # fileName passed as Java system property "-Dlogback.configurationFile"
       fileName: logback.xml
+  # metrics configuration for Ditto
+  metrics:
+    # metricsPrefix defines a prefix to use for all Ditto created metrics (counters, gauges, histograms)
+    metricsPrefix: ""
+    # systemMetrics contains the configuration for obtaining system metrics (via Kamon)
+    systemMetrics:
+      # enabled if enabled, system metrics are gathered
+      enabled: true
   # tracing configuration for Ditto
   tracing:
     # enabled whether tracing (via OpenTelemetry) is enabled
@@ -1069,6 +1077,22 @@ thingsSearch:
           throughput: 100
           # period the throttle period
           period: 30s
+    # operatorMetrics contains configuration for operator defined custom metrics, using a search "count" with namespaces and filter
+    operatorMetrics:
+      # enabled configures whether operator metrics should be enabled or not
+      enabled: true
+      # scrapeInterval defines the default scrape interval if a "customMetric" did not specify a custom scrape interval
+      scrapeInterval: 15m
+      # customMetrics holds a map of metric-names as key (e.g. "ditto_my_awesome_things") and custom metric config as value
+      customMetrics:
+      # ditto_my_awesome_things:
+      #   enabled: true
+      #   scrapeInterval: 5m
+      #   namespaces:
+      #     - "org.eclipse.ditto"
+      #   filter: "eq(attributes/awesome,true)"
+      #   tags:
+      #     foo: bar
 
 
 ## ----------------------------------------------------------------------------

documentation/src/main/resources/pages/ditto/installation-operating.md

@@ -1,7 +1,7 @@
 ---
 title: Operating Ditto
 tags: [installation]
-keywords: operating, docker, docker-compose, devops, logging, logstash, elk, monitoring, prometheus, grafana
+keywords: operating, docker, docker-compose, devops, logging, logstash, elk, monitoring, prometheus, grafana, tracing, metrics
 permalink: installation-operating.html
 ---
 
@@ -423,6 +423,61 @@ Have a look at the
 [example Grafana dashboards](https://github.com/eclipse-ditto/ditto/tree/master/deployment/operations/grafana-dashboards)
 and build and share new ones back to the Ditto community.
 
+### Operator defined custom metrics
+
+Starting with Ditto 3.5.0, it is possible to configure "custom metrics" which are gathered by counting things matching
+a defined namespace/filter combination.  
+This is configured via the [search](architecture-services-things-search.html) service configuration and builds on the
+[count things](basic-search.html#search-count-queries) functionality.
+
+The idea behind this is that you want to show some statistic (e.g. in Grafana) about the amount of "Things" managed in
+Ditto fulfilling a certain condition.
+
+This would be an example search service configuration snippet for e.g. providing a metric named 
+`all_produced_and_not_installed_devices` defining a query on existence of a `production-date` and absence of 
+an `installation-date` attribute:
+```hocon
+ditto {
+  search {
+    operator-metrics {
+      enabled = true
+      scrape-interval = 15m
+      custom-metrics {
+        all_produced_and_not_installed_devices {
+          scrape-interval = 5m # overwrite scrape interval, run each 5 minutes
+          namespaces = [
+            "org.eclipse.ditto.smokedetectors"
+            "org.eclipse.ditto.cameras"
+          ]
+          filter = "and(exists(attributes/production-date),not(exists(attributes/installation-date)))"
+          tags {
+            company = "acme-corp"
+          }
+        }
+      }
+    }
+  }
+}
+```
+
+In order to add custom metrics via System properties, the following example shows how the above metric can be configured:
+```
+-Dditto.search.operator-metrics.custom-metrics.all_produced_and_not_installed_devices.enabled=true
+-Dditto.search.operator-metrics.custom-metrics.all_produced_and_not_installed_devices.scrape-interval=5m
+-Dditto.search.operator-metrics.custom-metrics.all_produced_and_not_installed_devices.namespaces.0=org.eclipse.ditto.smokedetectors
+-Dditto.search.operator-metrics.custom-metrics.all_produced_and_not_installed_devices.namespaces.1=org.eclipse.ditto.cameras
+-Dditto.search.operator-metrics.custom-metrics.all_produced_and_not_installed_devices.filter=and(exists(attributes/production-date),not(exists(attributes/installation-date)))
+-Dditto.search.operator-metrics.custom-metrics.all_produced_and_not_installed_devices.tags.company=acme-corp
+```
+
+Ditto will perform a [count things operation](basic-search.html#search-count-queries) each `5m` (5 minutes), providing
+a gauge named `all_produced_and_not_installed_devices` with the count of the query, adding the tag `company="acme-corp"`.
+
+In Prometheus format this would look like:
+```
+all_produced_and_not_installed_devices{company="acme-corp"} 42.0
+```
+
 ## Tracing
 
 Ditto supports reading and propagating [W3C trace context](https://www.w3.org/TR/trace-context/) headers at the 

internal/utils/config/src/main/resources/ditto-metrics.conf

@@ -2,6 +2,10 @@ ditto.metrics {
   systemMetrics.enabled = true
   systemMetrics.enabled = ${?SYSTEM_METRICS_ENABLED}
 
+  # the metric prefix to apply for all gathered metrics in Ditto provided to Prometheus
+  metric-prefix = ""
+  metric-prefix = ${?DITTO_METRICS_METRIC_PREFIX}
+
   prometheus {
     enabled = true
     enabled = ${?PROMETHEUS_ENABLED}