[PATCH?] Locking when creating IndexWriter

[Victor Hadianto <vi...@nuix.com.au>]

Hello,

I am using lucene in an EJB environment. I have a message driven bean that 
subscribe to a queue that will consume the object that I want lucene to index.

Now the problem when I have many object in the queue, the Application Server 
will instantiated multiple message driven bean object and runs the indexing 
at the same time. When this happen I got this exception:

[IndexerMDB] Problem indexing email in indexer mdb
java.io.IOException: Index locked for write: 
Lock@/usr/kernel/jakartalucene/install/write.lock
        at org.apache.lucene.index.IndexWriter.<init>(Unknown Source)
        at org.apache.lucene.index.IndexWriter.<init>(Unknown Source)
        at com.nuix.indexer.IndexerMDB.indexData(IndexerMDB.java:304)

Only the first message driven bean will successfully index the data.

I had a look on the code and really FSDirectory will just simply fail if it 
can't create the new lock file! Is this done on purpose? Why can't 
IndexWriter tries for a few times to create the lock file? Do I miss 
something really big here?

I modified FSDirectory as follow so it works in our environment. Please 
comment on this change and just slam me if this is blatantly against lucene 
framework :D

Basically I changed it so it does not fail straight away, instead try and 
wait for creating the new file.

RCS file: 
/usr/local/cvsroot/nuix/kernel/jakartalucene/dist/src/java/org/apache/lucene/store/FSDirectory.java,v
retrieving revision 1.1.1.1
diff -u -u -r1.1.1.1 FSDirectory.java
--- FSDirectory.java    4 Apr 2002 01:14:11 -0000       1.1.1.1
+++ FSDirectory.java    22 May 2002 07:19:20 -0000
@@ -218,7 +218,19 @@
     return new Lock() {
        public boolean obtain() throws IOException {
           if (Constants.JAVA_1_1) return true;    // locks disabled in jdk 
1.1
-          return lockFile.createNewFile();
+          boolean locked = false;
+          locked = lockFile.createNewFile();
+          for (int count = 0; count < 100 && !locked; count++) {
+              try {
+                  Thread.sleep(100);
+                  locked = lockFile.createNewFile();
+              } catch (InterruptedException e) {
+                  e.printStackTrace();
+                  return false;
+              }
+              
+          }
+          return locked;
        }
        public void release() {
           if (Constants.JAVA_1_1) return;         // locks disabled in jdk 
1.1


Regards,

-- 
Victor Hadianto

-- 
Victor Hadianto

--
To unsubscribe, e-mail:   <ma...@jakarta.apache.org>
For additional commands, e-mail: <ma...@jakarta.apache.org>