Fix.

TODO.md

@@ -28,8 +28,6 @@ topics configurations. Could refactor the properties to more hierarhical structu
 
 23. Start using Avro or other binary messages for triggering queue. This Json crap is expensive?
 
-24. Add local extremums for most gauges.
-
 25. Check automatically if the concurrency policy returned is the same instance.
 Unfortunately, it is quite common for services to create a new instance everytime we ask it, for let's  say SimpleConcurrencyPolicy, and with
 doing that, losing any concurrency control.

tw-tasks-core-spring-boot-starter/src/main/java/com/transferwise/tasks/core/autoconfigure/TwTasksEnvironmentPostProcessor.java

@@ -0,0 +1,39 @@
+package com.transferwise.tasks.core.autoconfigure;
+
+import com.transferwise.tasks.helpers.CoreMetricsTemplate;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Set;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.env.EnvironmentPostProcessor;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.core.env.PropertySource;
+
+@Slf4j
+public class TwTasksEnvironmentPostProcessor implements EnvironmentPostProcessor {
+
+  private static final String PROPERTY_SOURCE_KEY = TwTasksEnvironmentPostProcessor.class.getName();
+  static final String TW_OBS_BASE_EXTREMUM_CONFIG_PATH = "transferwise.observability.base.metrics.local-extremum-gauge-names.tw-tasks";
+
+  @Override
+  public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
+    PropertySource<?> propertySource = environment.getPropertySources().get(PROPERTY_SOURCE_KEY);
+    if (propertySource == null) {
+      final HashMap<String, Object> map = new HashMap<>();
+
+      // Calculate last minute min/max using tw-observability-base local extremums.
+      Set<String> gaugeNames = new HashSet<>();
+      gaugeNames.add(CoreMetricsTemplate.GAUGE_METRIC_PROCESSING_ONGOING_TASKS_GRABBINGS_COUNT);
+      gaugeNames.add(CoreMetricsTemplate.GAUGE_PROCESSING_RUNNING_TASKS_COUNT);
+      gaugeNames.add(CoreMetricsTemplate.GAUGE_PROCESSING_IN_PROGRESS_TASKS_GRABBING_COUNT);
+      gaugeNames.add(CoreMetricsTemplate.GAUGE_TASKS_ONGOING_PROCESSINGS_COUNT);
+
+      map.put(TW_OBS_BASE_EXTREMUM_CONFIG_PATH, gaugeNames);
+
+      MapPropertySource mapPropertySource = new MapPropertySource(PROPERTY_SOURCE_KEY, map);
+      environment.getPropertySources().addLast(mapPropertySource);
+    }
+  }
+}

tw-tasks-core-spring-boot-starter/src/main/resources/META-INF/spring.factories

@@ -1,2 +1,3 @@
 org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.transferwise.tasks.core.autoconfigure.TwTasksCoreAutoConfiguration
 org.springframework.context.ApplicationListener=com.transferwise.tasks.TwTasksApplicationListener
+org.springframework.boot.env.EnvironmentPostProcessor=com.transferwise.tasks.core.autoconfigure.TwTasksEnvironmentPostProcessor