Add host system metrics.

src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java

@@ -25,9 +25,6 @@ import com.yammer.dropwizard.db.DatabaseConfiguration;
 import com.yammer.dropwizard.jdbi.DBIFactory;
 import com.yammer.dropwizard.migrations.MigrationsBundle;
 import com.yammer.metrics.Metrics;
-import com.yammer.metrics.core.Clock;
-import com.yammer.metrics.core.MetricPredicate;
-import com.yammer.metrics.reporting.DatadogReporter;
 import com.yammer.metrics.reporting.GraphiteReporter;
 import net.spy.memcached.MemcachedClient;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
@@ -49,7 +46,11 @@ import org.whispersystems.textsecuregcm.federation.FederatedPeer;
 import org.whispersystems.textsecuregcm.limits.RateLimiters;
 import org.whispersystems.textsecuregcm.mappers.IOExceptionMapper;
 import org.whispersystems.textsecuregcm.mappers.RateLimitExceededExceptionMapper;
+import org.whispersystems.textsecuregcm.metrics.CpuUsageGauge;
+import org.whispersystems.textsecuregcm.metrics.FreeMemoryGauge;
 import org.whispersystems.textsecuregcm.metrics.JsonMetricsReporter;
+import org.whispersystems.textsecuregcm.metrics.NetworkReceivedGauge;
+import org.whispersystems.textsecuregcm.metrics.NetworkSentGauge;
 import org.whispersystems.textsecuregcm.providers.MemcacheHealthCheck;
 import org.whispersystems.textsecuregcm.providers.MemcachedClientFactory;
 import org.whispersystems.textsecuregcm.providers.RedisClientFactory;
@@ -164,6 +165,11 @@ public class WhisperServerService extends Service<WhisperServerConfiguration> {
     environment.addProvider(new IOExceptionMapper());
     environment.addProvider(new RateLimitExceededExceptionMapper());
 
+    Metrics.newGauge(CpuUsageGauge.class, "cpu", new CpuUsageGauge());
+    Metrics.newGauge(FreeMemoryGauge.class, "free_memory", new FreeMemoryGauge());
+    Metrics.newGauge(NetworkSentGauge.class, "bytes_sent", new NetworkSentGauge());
+    Metrics.newGauge(NetworkReceivedGauge.class, "bytes_received", new NetworkReceivedGauge());
+
     if (config.getGraphiteConfiguration().isEnabled()) {
       GraphiteReporter.enable(15, TimeUnit.SECONDS,
                               config.getGraphiteConfiguration().getHost(),

src/main/java/org/whispersystems/textsecuregcm/metrics/CpuUsageGauge.java

@@ -0,0 +1,16 @@
+package org.whispersystems.textsecuregcm.metrics;
+
+import com.sun.management.OperatingSystemMXBean;
+import com.yammer.metrics.core.Gauge;
+
+import java.lang.management.ManagementFactory;
+
+public class CpuUsageGauge extends Gauge<Integer> {
+  @Override
+  public Integer value() {
+    OperatingSystemMXBean mbean = (com.sun.management.OperatingSystemMXBean)
+        ManagementFactory.getOperatingSystemMXBean();
+
+    return (int) Math.ceil(mbean.getSystemCpuLoad() * 100);
+  }
+}

src/main/java/org/whispersystems/textsecuregcm/metrics/FreeMemoryGauge.java

@@ -0,0 +1,20 @@
+package org.whispersystems.textsecuregcm.metrics;
+
+import com.sun.management.OperatingSystemMXBean;
+import com.yammer.metrics.core.Gauge;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.management.ManagementFactory;
+
+public class FreeMemoryGauge extends Gauge<Long> {
+
+  @Override
+  public Long value() {
+    OperatingSystemMXBean mbean = (com.sun.management.OperatingSystemMXBean)
+        ManagementFactory.getOperatingSystemMXBean();
+
+    return mbean.getFreePhysicalMemorySize();
+  }
+}

src/main/java/org/whispersystems/textsecuregcm/metrics/NetworkGauge.java

@@ -0,0 +1,37 @@
+package org.whispersystems.textsecuregcm.metrics;
+
+
+import com.yammer.metrics.core.Gauge;
+import org.whispersystems.textsecuregcm.util.Pair;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+
+public abstract class NetworkGauge extends Gauge<Long> {
+
+  protected Pair<Long, Long> getSentReceived() throws IOException {
+    File           proc          = new File("/proc/net/dev");
+    BufferedReader reader        = new BufferedReader(new FileReader(proc));
+    String         header        = reader.readLine();
+    String         header2       = reader.readLine();
+
+    long           bytesSent     = 0;
+    long           bytesReceived = 0;
+
+    String interfaceStats;
+
+      while ((interfaceStats = reader.readLine()) != null) {
+        String[] stats = interfaceStats.split("\\s+");
+
+        if (!stats[1].equals("lo:")) {
+          bytesReceived += Long.parseLong(stats[2]);
+          bytesSent     += Long.parseLong(stats[10]);
+        }
+      }
+
+    return new Pair<>(bytesSent, bytesReceived);
+  }
+}

src/main/java/org/whispersystems/textsecuregcm/metrics/NetworkReceivedGauge.java

@@ -0,0 +1,36 @@
+package org.whispersystems.textsecuregcm.metrics;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.whispersystems.textsecuregcm.util.Pair;
+
+import java.io.IOException;
+
+public class NetworkReceivedGauge extends NetworkGauge {
+
+  private final Logger logger = LoggerFactory.getLogger(NetworkSentGauge.class);
+
+  private long lastTimestamp;
+  private long lastReceived;
+
+  @Override
+  public Long value() {
+    try {
+      long             timestamp       = System.currentTimeMillis();
+      Pair<Long, Long> sentAndReceived = getSentReceived();
+      long             result          = 0;
+
+      if (lastTimestamp != 0) {
+        result       = sentAndReceived.second() - lastReceived;
+        lastReceived = sentAndReceived.second();
+      }
+
+      lastTimestamp = timestamp;
+      return result;
+    } catch (IOException e) {
+      logger.warn("NetworkReceivedGauge", e);
+      return -1L;
+    }
+  }
+
+}

src/main/java/org/whispersystems/textsecuregcm/metrics/NetworkSentGauge.java

@@ -0,0 +1,35 @@
+package org.whispersystems.textsecuregcm.metrics;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.whispersystems.textsecuregcm.util.Pair;
+
+import java.io.IOException;
+
+public class NetworkSentGauge extends NetworkGauge {
+
+  private final Logger logger = LoggerFactory.getLogger(NetworkSentGauge.class);
+
+  private long lastTimestamp;
+  private long lastSent;
+
+  @Override
+  public Long value() {
+    try {
+      long             timestamp       = System.currentTimeMillis();
+      Pair<Long, Long> sentAndReceived = getSentReceived();
+      long             result          = 0;
+
+      if (lastTimestamp != 0) {
+        result        = sentAndReceived.first() - lastSent;
+        lastSent      = sentAndReceived.first();
+      }
+
+      lastTimestamp = timestamp;
+      return result;
+    } catch (IOException e) {
+      logger.warn("NetworkSentGauge", e);
+      return -1L;
+    }
+  }
+}