From fa1f80f40da0bb629c40bf09791c6c90f2608774 Mon Sep 17 00:00:00 2001
From: Jonathan Ellis <jbellis@apache.org>
Date: Fri, 17 Apr 2009 20:08:10 +0000
Subject: [PATCH] make GC_GRACE_IN_SECONDS customizable in storage.conf. patch
 by jbellis; reviewed by Eric Evans for #33

git-svn-id: https://svn.apache.org/repos/asf/incubator/cassandra/trunk@766134 13f79535-47bb-0310-9956-ffa450edef68
---
 conf/storage-conf.xml                          |  6 ++++++
 .../cassandra/config/DatabaseDescriptor.java   | 18 +++++++++++++-----
 .../apache/cassandra/db/ColumnFamilyStore.java |  4 +---
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/conf/storage-conf.xml b/conf/storage-conf.xml
index 254619b7cb..129362f506 100644
--- a/conf/storage-conf.xml
+++ b/conf/storage-conf.xml
@@ -45,6 +45,12 @@
    <BootstrapFileDirectory>/var/cassandra/bootstrap</BootstrapFileDirectory>
    <StagingFileDirectory>/var/cassandra/staging</StagingFileDirectory>
    <CommitLogFastSync>false</CommitLogFastSync>
+   <!-- Time to wait before garbage-collection deletion markers.
+        Set this to a large enough value that you are confident
+        that the deletion marker will be propagated to all replicas
+        by the time this many seconds has elapsed, even in the
+        face of hardware failures.  The default value is ten days. -->
+   <GCGraceSeconds>864000</GCGraceSeconds>
    <Tables>
      <Table Name = "Table1">
        <ColumnFamily ColumnSort="Name" Name="Standard1"/>
diff --git a/src/org/apache/cassandra/config/DatabaseDescriptor.java b/src/org/apache/cassandra/config/DatabaseDescriptor.java
index 4572985095..d0acc30993 100644
--- a/src/org/apache/cassandra/config/DatabaseDescriptor.java
+++ b/src/org/apache/cassandra/config/DatabaseDescriptor.java
@@ -27,14 +27,11 @@ import org.apache.log4j.Logger;
 import org.apache.cassandra.db.ColumnFamily;
 import org.apache.cassandra.db.Table;
 import org.apache.cassandra.db.TypeInfo;
-import org.apache.cassandra.db.DBManager;
 import org.apache.cassandra.db.SystemTable;
-import org.apache.cassandra.db.Table.TableMetadata;
 import org.apache.cassandra.utils.FileUtils;
 import org.apache.cassandra.utils.XMLUtils;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
-import org.apache.cassandra.io.*;
 
 
 /**
@@ -116,10 +113,12 @@ public class DatabaseDescriptor
     private static String jobTrackerHost_;    
     /* Zookeeper session timeout. */
     private static int zkSessionTimeout_ = 30000;
-    
+    /* time to wait before garbage collecting tombstones (deletion markers) */
+    private static int gcGraceInSeconds_ = 10 * 24 * 3600; // 10 days
+
     // the path qualified config file (storage-conf.xml) name
     private static String configFileName_;
-    
+
     static
     {
         try
@@ -148,6 +147,10 @@ public class DatabaseDescriptor
             /* Job Jar file location */
             jobJarFileLocation_ = xmlUtils.getNodeValue("/Storage/JobJarFileLocation");
 
+            String gcGrace = xmlUtils.getNodeValue("/Storage/GCGraceSeconds");
+            if ( gcGrace != null )
+                gcGraceInSeconds_ = Integer.parseInt(gcGrace);
+
             /* Zookeeper's session timeout */
             String zkSessionTimeout = xmlUtils.getNodeValue("/Storage/ZookeeperSessionTimeout");
             if ( zkSessionTimeout != null )
@@ -462,6 +465,11 @@ public class DatabaseDescriptor
         }
     }
 
+    public static int getGcGraceInSeconds()
+    {
+        return gcGraceInSeconds_;
+    }
+
     public static String getHashingStrategy()
     {
         return hashingStrategy_;
diff --git a/src/org/apache/cassandra/db/ColumnFamilyStore.java b/src/org/apache/cassandra/db/ColumnFamilyStore.java
index 6cb974fbf4..fbfa0f8be0 100644
--- a/src/org/apache/cassandra/db/ColumnFamilyStore.java
+++ b/src/org/apache/cassandra/db/ColumnFamilyStore.java
@@ -616,8 +616,6 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean
         return removeDeleted(cf);
     }
 
-    static final int GC_GRACE_IN_SECONDS = 10 * 24 * 3600; // 10 days
-
     /*
      This is complicated because we need to preserve deleted columns, supercolumns, and columnfamilies
      until they have been deleted for at least GC_GRACE_IN_SECONDS.  But, we do not need to preserve
@@ -626,7 +624,7 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean
      */
     static ColumnFamily removeDeleted(ColumnFamily cf)
     {
-        return removeDeleted(cf, (int)(System.currentTimeMillis() / 1000) - GC_GRACE_IN_SECONDS);
+        return removeDeleted(cf, (int)(System.currentTimeMillis() / 1000) - DatabaseDescriptor.getGcGraceInSeconds());
     }
 
     static ColumnFamily removeDeleted(ColumnFamily cf, int gcBefore)