From a3fd08b7ef855f66677596526b22aa02f82f15d5 Mon Sep 17 00:00:00 2001
From: Moxie Marlinspike <moxie@thoughtcrime.org>
Date: Thu, 30 Jul 2015 16:55:19 -0700
Subject: [PATCH] Add gauge for reporting number of open fds

// FREEBIE
---
 .../textsecuregcm/WhisperServerService.java   |  2 ++
 .../metrics/FileDescriptorGauge.java          | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 src/main/java/org/whispersystems/textsecuregcm/metrics/FileDescriptorGauge.java

diff --git a/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java b/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
index 76c0a4b49..9cc10c780 100644
--- a/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
+++ b/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
@@ -53,6 +53,7 @@ import org.whispersystems.textsecuregcm.mappers.IOExceptionMapper;
 import org.whispersystems.textsecuregcm.mappers.InvalidWebsocketAddressExceptionMapper;
 import org.whispersystems.textsecuregcm.mappers.RateLimitExceededExceptionMapper;
 import org.whispersystems.textsecuregcm.metrics.CpuUsageGauge;
+import org.whispersystems.textsecuregcm.metrics.FileDescriptorGauge;
 import org.whispersystems.textsecuregcm.metrics.FreeMemoryGauge;
 import org.whispersystems.textsecuregcm.metrics.NetworkReceivedGauge;
 import org.whispersystems.textsecuregcm.metrics.NetworkSentGauge;
@@ -263,6 +264,7 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
     environment.metrics().register(name(FreeMemoryGauge.class, "free_memory"), new FreeMemoryGauge());
     environment.metrics().register(name(NetworkSentGauge.class, "bytes_sent"), new NetworkSentGauge());
     environment.metrics().register(name(NetworkReceivedGauge.class, "bytes_received"), new NetworkReceivedGauge());
+    environment.metrics().register(name(FileDescriptorGauge.class, "fd_count"), new FileDescriptorGauge());
 
     if (config.getGraphiteConfiguration().isEnabled()) {
       GraphiteReporterFactory graphiteReporterFactory = new GraphiteReporterFactory();
diff --git a/src/main/java/org/whispersystems/textsecuregcm/metrics/FileDescriptorGauge.java b/src/main/java/org/whispersystems/textsecuregcm/metrics/FileDescriptorGauge.java
new file mode 100644
index 000000000..3ea1325f7
--- /dev/null
+++ b/src/main/java/org/whispersystems/textsecuregcm/metrics/FileDescriptorGauge.java
@@ -0,0 +1,19 @@
+package org.whispersystems.textsecuregcm.metrics;
+
+
+import com.codahale.metrics.Gauge;
+
+import java.io.File;
+
+public class FileDescriptorGauge implements Gauge<Integer> {
+  @Override
+  public Integer getValue() {
+    File file = new File("/proc/self/fd");
+
+    if (file.isDirectory() && file.exists()) {
+      return file.list().length;
+    }
+
+    return 0;
+  }
+}