[tor-commits] [collector/master] Provide a shutdown-hook that allows running modules to finish properly.

[karsten at torproject.org]

commit 7cec1c874adffd14b7f152e289a0ccdc7cac7ad5
Author: iwakeh <iwakeh at torproject.org>
Date:   Mon Sep 5 20:54:09 2016 +0200

    Provide a shutdown-hook that allows running modules to finish properly.
    
    Implements task-19016. Adapted logback default to log shutdown-hook
    log statements also to the console.
    
    Corrected coverage-check values.
---
 build.xml                                          |  4 ++--
 src/main/java/org/torproject/collector/Main.java   |  2 ++
 .../org/torproject/collector/cron/Scheduler.java   |  8 ++++---
 .../torproject/collector/cron/ShutdownHook.java    | 28 ++++++++++++++++++++++
 src/main/resources/logback.xml                     |  9 +++++++
 5 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/build.xml b/build.xml
index 1e292b7..11d1f92 100644
--- a/build.xml
+++ b/build.xml
@@ -280,13 +280,13 @@
         <include name="**/*.java" />
       </fileset>
     </cobertura-report>
-    <cobertura-check totallinerate="5" totalbranchrate="1" >
+    <cobertura-check totallinerate="7" totalbranchrate="2" >
       <regex pattern="org.torproject.collector.conf"
              branchrate="87" linerate="100"/>
       <regex pattern="org.torproject.collector.cron"
              branchrate="50" linerate="71" />
       <regex pattern="org.torproject.collector.Main"
-             branchrate="100" linerate="100" />
+             branchrate="100" linerate="91" />
     </cobertura-check>
   </target>
   <target name="test" depends="compile,compile-tests">
diff --git a/src/main/java/org/torproject/collector/Main.java b/src/main/java/org/torproject/collector/Main.java
index 997ee2a..289cf30 100644
--- a/src/main/java/org/torproject/collector/Main.java
+++ b/src/main/java/org/torproject/collector/Main.java
@@ -9,6 +9,7 @@ import org.torproject.collector.conf.ConfigurationException;
 import org.torproject.collector.conf.Key;
 import org.torproject.collector.cron.CollecTorMain;
 import org.torproject.collector.cron.Scheduler;
+import org.torproject.collector.cron.ShutdownHook;
 import org.torproject.collector.exitlists.ExitListDownloader;
 import org.torproject.collector.index.CreateIndexJson;
 import org.torproject.collector.relaydescs.ArchiveWriter;
@@ -79,6 +80,7 @@ public class Main {
       printUsage(ce.getMessage());
       return;
     }
+    Runtime.getRuntime().addShutdownHook(new ShutdownHook());
   }
 
   private static void printUsage(String msg) {
diff --git a/src/main/java/org/torproject/collector/cron/Scheduler.java b/src/main/java/org/torproject/collector/cron/Scheduler.java
index 12fe1bb..1e72dc0 100644
--- a/src/main/java/org/torproject/collector/cron/Scheduler.java
+++ b/src/main/java/org/torproject/collector/cron/Scheduler.java
@@ -29,6 +29,8 @@ public final class Scheduler implements ThreadFactory {
   public static final String ACTIVATED = "Activated";
   public static final String PERIODMIN = "PeriodMinutes";
   public static final String OFFSETMIN = "OffsetMinutes";
+  private static final long GRACE_MIN = 20L;
+  private static final long MILLIS_IN_A_MINUTE = 60_000L;
 
   private static final Logger logger = LoggerFactory.getLogger(Scheduler.class);
 
@@ -89,8 +91,6 @@ public final class Scheduler implements ThreadFactory {
     }
   }
 
-  private static final long MILLIS_IN_A_MINUTE = 60_000L;
-
   private void scheduleExecutions(CollecTorMain ctm, int offset, int period) {
     logger.info("Periodic updater started for " + ctm.getClass().getName()
         + "; offset=" + offset + ", period=" + period + ".");
@@ -118,8 +118,10 @@ public final class Scheduler implements ThreadFactory {
    */
   public void shutdownScheduler() {
     try {
+      logger.info("Waiting at most {} minutes for termination "
+          + "of running tasks ... ", GRACE_MIN);
       scheduler.shutdown();
-      scheduler.awaitTermination(20L, java.util.concurrent.TimeUnit.MINUTES);
+      scheduler.awaitTermination(GRACE_MIN, java.util.concurrent.TimeUnit.MINUTES);
       logger.info("Shutdown of all scheduled tasks completed successfully.");
     } catch (InterruptedException ie) {
       List<Runnable> notTerminated = scheduler.shutdownNow();
diff --git a/src/main/java/org/torproject/collector/cron/ShutdownHook.java b/src/main/java/org/torproject/collector/cron/ShutdownHook.java
new file mode 100644
index 0000000..519f16d
--- /dev/null
+++ b/src/main/java/org/torproject/collector/cron/ShutdownHook.java
@@ -0,0 +1,28 @@
+/* Copyright 2016 The Tor Project
+ * See LICENSE for licensing information */
+
+package org.torproject.collector.cron;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Scheduler that starts the modules configured in collector.properties.
+ */
+public final class ShutdownHook extends Thread {
+
+  private static final Logger log = LoggerFactory.getLogger(ShutdownHook.class);
+
+  /** Names the shutdown thread for debugging purposes. */
+  public ShutdownHook() {
+    super("CollecTor-ShutdownThread");
+  }
+
+  @Override
+  public void run() {
+    log.info("Shutdown in progress ... ");
+    Scheduler.getInstance().shutdownScheduler();
+    log.info("Shutdown finished. Exiting.");
+  }
+}
+
diff --git a/src/main/resources/logback.xml b/src/main/resources/logback.xml
index 2d8a1ce..1d97d00 100644
--- a/src/main/resources/logback.xml
+++ b/src/main/resources/logback.xml
@@ -25,6 +25,12 @@
     </filter>
   </appender>
 
+  <appender name="SHUTDOWN" class="ch.qos.logback.core.ConsoleAppender">
+    <encoder>
+      <pattern>${utc-date-pattern} %level %logger{20}:%line %msg%n</pattern>
+    </encoder>
+  </appender>
+
   <appender name="FILEALL" class="ch.qos.logback.core.rolling.RollingFileAppender">
     <file>${fileall-logname}.log</file>
     <encoder>
@@ -146,6 +152,9 @@
     <appender-ref ref="CONSOLE" />
   </logger>
 
+  <logger name="org.torproject.collector.cron.ShutdownHook" >
+    <appender-ref ref="SHUTDOWN" />
+  </logger>
 
   <root level="ALL">
     <appender-ref ref="FILEALL" />