[CASSANDRA-5185] symlinks to data directories are broken in 1.2.0

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 1.2.2
• Severity: Normal
• Assignee: Yuki Morishita
• Reporter: Jeremiah Jordan

Authors

Yuki Morishita

Reviewers

Jonathan Ellis

• Created: 24/Jan/13 21:09
• Updated: 16/Apr/19 09:32
• Resolved: 28/Jan/13 16:13

Description

symlinks to data directories is broken in 1.2.0

cd ~
tar xzf apache-cassandra-1.2.0-bin.tar.gz
cd apache-cassandra-1.2.0/conf
vim cassandra.yaml
#set data/commitlog/savecache dirs to
#~/apache-cassandra-1.2.0/var/...
cd ../bin
# start once to make folders
./cassandra -f
#cntrl-c
cd ..
mkdir var/lib/cassandra2
mv var/lib/cassandra/data/system var/lib/cassandra2/system
cd var/lib/cassandra/data
ln -s ../../cassandra2/system .
cd ~/apache-cassandra-1.2.0/bin/
cassandra -f
#get lots of assertion errors see attached log file

 INFO 21:59:44,883 Enqueuing flush of Memtable-local@1578022692(52/52 serialized/live bytes, 2 ops)
 INFO 21:59:44,890 Writing Memtable-local@1578022692(52/52 serialized/live bytes, 2 ops)
ERROR 21:59:44,892 Exception in thread Thread[FlushWriter:1,5,main]
java.lang.AssertionError
	at org.apache.cassandra.io.sstable.Descriptor.<init>(Descriptor.java:190)
	at org.apache.cassandra.db.ColumnFamilyStore.getTempSSTablePath(ColumnFamilyStore.java:593)
	at org.apache.cassandra.db.ColumnFamilyStore.getTempSSTablePath(ColumnFamilyStore.java:588)
	at org.apache.cassandra.db.Memtable$FlushRunnable.writeSortedContents(Memtable.java:428)
	at org.apache.cassandra.db.Memtable$FlushRunnable.runWith(Memtable.java:417)
	at org.apache.cassandra.io.util.DiskAwareRunnable.runMayThrow(DiskAwareRunnable.java:48)
	at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)

I traced it back some, I think it is coming from:

org.apache.cassandra.db.Memtable$FlushRunnable.writeSortedContents(Memtable.java:428)
which calls: cfs.directories.getLocationForDisk(dataDirectory)

    public File getLocationForDisk(File dataDirectory)
    {
        for (File dir : sstableDirectories)
        {
            if (FileUtils.getCanonicalPath(dir).startsWith(FileUtils.getCanonicalPath(dataDirectory)))
                return dir;
        }
        return null;
    }

My guess is that the FileUtils.getCanonicalPath calls aren't matching because of the symlinks. So null is being returned there.