cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From jbel...@apache.org
Subject svn commit: r1040691 - in /cassandra/branches/cassandra-0.7: ./ conf/ src/java/org/apache/cassandra/config/ src/java/org/apache/cassandra/db/commitlog/ src/java/org/apache/cassandra/io/util/
Date Tue, 30 Nov 2010 18:45:08 GMT
Author: jbellis
Date: Tue Nov 30 18:45:08 2010
New Revision: 1040691

URL: http://svn.apache.org/viewvc?rev=1040691&view=rev
Log:
add flush for each append to periodiccommitlog mode; added periodic_without_flush option to
disable this
patch by jbellis; reviewed by brandonwilliams for CASSANDRA-1780

Modified:
    cassandra/branches/cassandra-0.7/CHANGES.txt
    cassandra/branches/cassandra-0.7/conf/cassandra.yaml
    cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/config/Config.java
    cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLog.java
    cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
    cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/io/util/BufferedRandomAccessFile.java

Modified: cassandra/branches/cassandra-0.7/CHANGES.txt
URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/CHANGES.txt?rev=1040691&r1=1040690&r2=1040691&view=diff
==============================================================================
--- cassandra/branches/cassandra-0.7/CHANGES.txt (original)
+++ cassandra/branches/cassandra-0.7/CHANGES.txt Tue Nov 30 18:45:08 2010
@@ -18,6 +18,8 @@ dev
    defined comparator, and decode properly in cli (CASSANDRA-1773)
  * use cross-platform newlines in cli (CASSANDRA-1786)
  * add ExpiringColumn support to sstable import/export (CASSANDRA-1754)
+ * add flush for each append to periodic commitlog mode; added
+   periodic_without_flush option to disable this (CASSANDRA-1780)
 
 
 0.7.0-rc1

Modified: cassandra/branches/cassandra-0.7/conf/cassandra.yaml
URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/conf/cassandra.yaml?rev=1040691&r1=1040690&r2=1040691&view=diff
==============================================================================
--- cassandra/branches/cassandra-0.7/conf/cassandra.yaml (original)
+++ cassandra/branches/cassandra-0.7/conf/cassandra.yaml Tue Nov 30 18:45:08 2010
@@ -61,17 +61,32 @@ saved_caches_directory: /var/lib/cassand
 # Size to allow commitlog to grow to before creating a new segment 
 commitlog_rotation_threshold_in_mb: 128
 
-# commitlog_sync may be either "periodic" or "batch." 
-# When in batch mode, Cassandra won't ack writes until the commit log
-# has been fsynced to disk.  It will wait up to
-# CommitLogSyncBatchWindowInMS milliseconds for other writes, before
-# performing the sync.
+# commitlog_sync supports the following modes:
+# 
+# batch:
+# In batch mode, Cassandra won't ack writes until the commit log
+# has been fsynced to disk.  But fsyncing each write at once is
+# performance-prohibitive, so instead Cassandra will wait up to
+# commitlog_sync_batch_window_in_ms milliseconds for other writes, before
+# syncing that "batch" at once.  This causes a performance penalty
+# of about 15% when the commitlog is on a separate device, and much more
+# when it shares the same device as the data files.
+#
+# periodic:
+# Writes may be acked immediately (without waiting for the commitlog
+# append) and the CommitLog is simply synced every
+# commitlog_sync_period_in_ms milliseconds.
+#
+# periodic_without_flush:
+# Like periodic, but the commitlog write buffer is only flushed
+# before the sync, so any interruption to the process can be
+# expected to lose some writes.  This is the old 0.6 periodic
+# behavior and will be removed in future versions if testing
+# continues to show no performance benefit over normal periodic.
 commitlog_sync: periodic
-
-# the other option is "timed," where writes may be acked immediately
-# and the CommitLog is simply synced every commitlog_sync_period_in_ms
-# milliseconds.
 commitlog_sync_period_in_ms: 10000
+# commitlog_sync: batch
+# commitlog_sync_batch_window_in_ms: 10
 
 # Addresses of hosts that are deemed contact points.
 # Cassandra nodes use this list of hosts to find each other and learn

Modified: cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/config/Config.java
URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/config/Config.java?rev=1040691&r1=1040690&r2=1040691&view=diff
==============================================================================
--- cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/config/Config.java (original)
+++ cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/config/Config.java Tue
Nov 30 18:45:08 2010
@@ -105,7 +105,8 @@ public class Config
     
     public static enum CommitLogSync {
         periodic,
-        batch
+        batch,
+        periodic_without_flush
     }
     
     public static enum DiskAccessMode {

Modified: cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLog.java
URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLog.java?rev=1040691&r1=1040690&r2=1040691&view=diff
==============================================================================
--- cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLog.java
(original)
+++ cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLog.java
Tue Nov 30 18:45:08 2010
@@ -112,7 +112,11 @@ public class CommitLog
         // All we need to do is create a new one.
         segments.add(new CommitLogSegment());
 
-        if (DatabaseDescriptor.getCommitLogSync() == Config.CommitLogSync.periodic)
+        if (DatabaseDescriptor.getCommitLogSync() == Config.CommitLogSync.batch)
+        {
+            executor = new BatchCommitLogExecutorService();
+        }
+        else
         {
             executor = new PeriodicCommitLogExecutorService();
             final Callable syncer = new Callable()
@@ -147,10 +151,6 @@ public class CommitLog
                 }
             }, "PERIODIC-COMMIT-LOG-SYNCER").start();
         }
-        else
-        {
-            executor = new BatchCommitLogExecutorService();
-        }
     }
 
     public void resetUnsafe()
@@ -490,6 +490,7 @@ public class CommitLog
 
     // TODO this should be a Runnable since it doesn't actually return anything, but it's
difficult to do that
     // without breaking the fragile CheaterFutureTask in BatchCLES.
+    final static boolean flushEachWrite = DatabaseDescriptor.getCommitLogSync() == Config.CommitLogSync.periodic;
     class LogRecordAdder implements Callable, Runnable
     {
         final RowMutation rowMutation;
@@ -512,6 +513,10 @@ public class CommitLog
                     sync();
                     segments.add(new CommitLogSegment());
                 }
+                else if (flushEachWrite)
+                {
+                    currentSegment().flush();
+                }
             }
             catch (IOException e)
             {

Modified: cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java?rev=1040691&r1=1040690&r2=1040691&view=diff
==============================================================================
--- cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
(original)
+++ cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/db/commitlog/CommitLogSegment.java
Tue Nov 30 18:45:08 2010
@@ -140,6 +140,11 @@ public class CommitLogSegment
         logWriter.sync();
     }
 
+    public void flush() throws IOException
+    {
+        logWriter.flush();
+    }
+
     public CommitLogContext getContext()
     {
         return new CommitLogContext(logWriter.getFilePointer());

Modified: cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/io/util/BufferedRandomAccessFile.java
URL: http://svn.apache.org/viewvc/cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/io/util/BufferedRandomAccessFile.java?rev=1040691&r1=1040690&r2=1040691&view=diff
==============================================================================
--- cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/io/util/BufferedRandomAccessFile.java
(original)
+++ cassandra/branches/cassandra-0.7/src/java/org/apache/cassandra/io/util/BufferedRandomAccessFile.java
Tue Nov 30 18:45:08 2010
@@ -19,10 +19,8 @@
 package org.apache.cassandra.io.util;
 
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.RandomAccessFile;
-import java.util.Arrays;
 
 /**
  * A <code>BufferedRandomAccessFile</code> is like a
@@ -168,7 +166,7 @@ public class BufferedRandomAccessFile ex
     {
         if (syncNeeded_)
         {
-            flushBuffer();
+            flush();
             getChannel().force(true); // true, because file length counts as "metadata"
             syncNeeded_ = false;
         }
@@ -182,7 +180,7 @@ public class BufferedRandomAccessFile ex
     }
     
     /* Flush any dirty bytes in the buffer to disk. */
-    private void flushBuffer() throws IOException
+    public void flush() throws IOException
     {   
         if (this.dirty_)
         {
@@ -229,7 +227,7 @@ public class BufferedRandomAccessFile ex
      */
     private void reBuffer() throws IOException
     {
-        this.flushBuffer();
+        this.flush();
         this.lo_ = this.curr_;
         this.maxHi_ = this.lo_ + (long) this.buff_.length;
         if (this.diskPos_ != this.lo_)



Mime
View raw message