Thread: [Bigdata-commit] SF.net SVN: bigdata:[3384] branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/ bigdat

SourceForge Headquarters 225 Broadway Suite 1600 San Diego, CA 92101 +1 (858) 422-6466

Revision: 3384
          http://bigdata.svn.sourceforge.net/bigdata/?rev=3384&view=rev
Author:   martyncutcher
Date:     2010-08-02 09:33:17 +0000 (Mon, 02 Aug 2010)

Log Message:
-----------
Add support for breadcrumbing address useage - add/write/clear/remove - to track down rare errors.

Modified Paths:
--------------
    branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCache.java
    branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCacheService.java

Modified: branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCache.java
===================================================================

--- branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCache.java	2010-08-02 00:49:40 UTC (rev 3383)
+++ branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCache.java	2010-08-02 09:33:17 UTC (rev 3384)
@@ -1634,6 +1634,9 @@
 				view.position(pos);
 
 				final long offset = entry.getKey(); // offset in file to update
+				
+				registerWriteStatus(offset, md.recordLength, 'W');
+
 				nwrites += FileChannelUtility.writeAll(opener, view, offset);
 				// if (log.isInfoEnabled())
 				// log.info("writing to: " + offset);
@@ -1757,6 +1760,10 @@
 		}
 	}
 
+	protected void registerWriteStatus(long offset, int length, char action) {
+		// NOP to be overidden for debug if required
+	}
+
 	boolean m_written = false;
 
 	private long lastOffset;
@@ -1792,7 +1799,10 @@
 				 * Using the conditional remove on ConcurrentMap guards against
 				 * this.
 				 */
-				serviceRecordMap.remove(addr, this);
+				boolean removed = serviceRecordMap.remove(addr, this);
+				
+				registerWriteStatus(addr, 0, removed ? 'R' : 'L');
+
 			}
 
 		} else {

Modified: branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCacheService.java
===================================================================
--- branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCacheService.java	2010-08-02 00:49:40 UTC (rev 3383)
+++ branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/bigdata/io/writecache/WriteCacheService.java	2010-08-02 09:33:17 UTC (rev 3384)
@@ -313,8 +313,22 @@
 	 * {@link #writeChk(long, ByteBuffer, int)}).
 	 */
 	final private WriteCache[] buffers;
-
+	
 	/**
+	 * Debug arrays to chase down write/removal errors.
+	 * 
+	 * Toggle comment appropriately to activate/deactivate
+	 */
+	final long[] addrsUsed = new long[4024 * 1024];
+	int addrsUsedCurs = 0;
+	final char[] addrActions = new char[addrsUsed.length];
+	final int[] addrLens = new int[addrsUsed.length];
+//	final long[] addrsUsed = null;
+//	int addrsUsedCurs = 0;
+//	final char[] addrActions = null;
+//	final int[] addrLens = null;
+	
+	/**
 	 * The current file extent.
 	 */
 	final private AtomicLong fileExtent = new AtomicLong(-1L);
@@ -1422,6 +1436,7 @@
 			final WriteCache cache = acquireForWriter();
 
 			try {
+				debugAddrs(offset, 0, 'A');
 
 				// write on the cache.
 				if (cache.write(offset, data, chk, useChecksum)) {
@@ -1598,6 +1613,19 @@
 
 	}
 
+	public void debugAddrs(long offset, int length, char c) {
+		if (addrsUsed != null) {
+			addrsUsed[addrsUsedCurs] = offset;
+			addrActions[addrsUsedCurs] = c;
+			addrLens[addrsUsedCurs] = length;
+			
+			addrsUsedCurs++;
+			if (addrsUsedCurs >= addrsUsed.length) {
+				addrsUsedCurs = 0;
+			}
+		}
+	}
+
 	/**
 	 * Write a record whose size (when combined with the optional checksum) is
 	 * larger than the capacity of an individual {@link WriteCache} buffer. This
@@ -1917,6 +1945,7 @@
 			if (cache == null)
 				return;
 			acquireForWriter(); // in case current
+			debugAddrs(offset, 0, 'F');
 			try {
 				cache.clearAddrMap(offset);
 			} finally {
@@ -1928,6 +1957,41 @@
 	}
 
 	/**
+	 * An array of writeCache actions is maintained that can be used
+	 * to provide a breadcrumb of how that address has been written, saved,
+	 * freed or removed.
+	 * 
+	 * Write errors often show up as a checksum error, so the length of
+	 * data written to the address cab be crucial information in determining the
+	 * root of any problem.
+	 * 
+	 * @param address for which info requested
+	 * @return summary of writeCache actions
+	 */
+	public String addrDebugInfo(final long paddr) {
+		if (addrsUsed == null) {
+			return "No WriteCache debug info";
+		}
+		
+		StringBuffer ret = new StringBuffer();
+		// first see if address was ever written
+		boolean written = false;
+		for (int i = 0; i < addrsUsed.length; i++) {
+			if (i == addrsUsedCurs) {
+				ret.append("|...|");
+			}
+			if (addrsUsed[i] == paddr) {
+				ret.append(addrActions[i]);
+				if (addrActions[i]=='W') {
+					ret.append("[" + addrLens[i] + "]");
+				}
+			}
+		}
+		
+		return ret.toString();
+	}
+
+	/**
 	 * Performance counters for the {@link WriteCacheService}.
 	 * 
 	 * @author <a href="mailto:tho...@us...">Bryan


This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.




Thread: [Bigdata-commit] SF.net SVN: bigdata:[3384] branches/JOURNAL_HA_BRANCH/bigdata/src/java/com/ bigdat

Fast, scalable, robust graph database platform

bigdata-commit