Voeg een max direct memory size meter toe.

vpro-shared-monitoring/src/main/java/nl/vpro/monitoring/binder/JvmMaxDirectMemorySize.java

@@ -0,0 +1,62 @@
+package nl.vpro.monitoring.binder;
+
+import io.micrometer.common.lang.NonNull;
+import io.micrometer.core.instrument.*;
+import io.micrometer.core.instrument.binder.BaseUnits;
+import io.micrometer.core.instrument.binder.MeterBinder;
+
+import java.lang.management.ManagementFactory;
+import java.util.concurrent.atomic.AtomicLong;
+
+import com.sun.management.HotSpotDiagnosticMXBean;
+import com.sun.management.VMOption;
+
+import static java.util.Collections.emptyList;
+
+public class JvmMaxDirectMemorySize implements MeterBinder {
+
+    private static final String MAX_DIRECT_MEMORY_SIZE = "MaxDirectMemorySize";
+    private final Iterable<Tag> tags;
+    private final AtomicLong maxDirectMemorySize = new AtomicLong();
+
+    public JvmMaxDirectMemorySize() {
+        this(emptyList());
+    }
+
+    public JvmMaxDirectMemorySize(Iterable<Tag> tags) {
+        this.tags = tags;
+    }
+
+
+    @Override
+    public void bindTo(@NonNull MeterRegistry registry) {
+        setMaxDirectMemorySize();
+        Iterable<Tag> tagsWithId = Tags.concat(tags, "id", "direct");
+
+        Gauge.builder("jvm.buffer.memory.max.bytes", maxDirectMemorySize, AtomicLong::get)
+            .tags(tagsWithId)
+            .description("The maximum number of bytes that can be allocated to direct memory")
+            .baseUnit(BaseUnits.BYTES)
+            .strongReference(true)
+            .register(registry);
+
+    }
+
+    private void setMaxDirectMemorySize() {
+
+        HotSpotDiagnosticMXBean diagnosticMXBean = ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class);
+        maxDirectMemorySize.set(0);
+        if (diagnosticMXBean != null) {
+            VMOption option = diagnosticMXBean.getVMOption(MAX_DIRECT_MEMORY_SIZE);
+            if (option != null) {
+                try {
+                    maxDirectMemorySize.set(Long.parseLong(option.getValue()));
+                } catch (NumberFormatException ignored) {
+                }
+            }
+        }
+        if (maxDirectMemorySize.get() == 0) {
+            maxDirectMemorySize.set(Runtime.getRuntime().maxMemory());
+        }
+    }
+}

vpro-shared-monitoring/src/main/java/nl/vpro/monitoring/config/MonitoringConfig.java

@@ -1,8 +1,6 @@
 package nl.vpro.monitoring.config;
 
-import io.micrometer.core.instrument.Gauge;
-import io.micrometer.core.instrument.MeterRegistry;
-import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.*;
 import io.micrometer.core.instrument.binder.cache.JCacheMetrics;
 import io.micrometer.core.instrument.binder.db.PostgreSQLDatabaseMetrics;
 import io.micrometer.core.instrument.binder.jvm.*;
@@ -39,6 +37,7 @@
 
 import nl.vpro.logging.Slf4jHelper;
 import nl.vpro.logging.simple.Level;
+import nl.vpro.monitoring.binder.JvmMaxDirectMemorySize;
 import nl.vpro.util.locker.ObjectLocker;
 import nl.vpro.util.locker.ObjectLockerAdmin;
 
@@ -154,6 +153,7 @@ protected void configure(MeterRegistry registry) {
         }
         if (properties.isMeterJvmMemory()) {
             new JvmMemoryMetrics().bindTo(registry);
+            new JvmMaxDirectMemorySize().bindTo(registry);
         }
         if (properties.isMeterJvmThread()) {
             new JvmThreadMetrics().bindTo(registry);