Hi,
I tried to reuse the IndexSearcher, but I have another question. What happen if an
application server unloads the class after it is idle for a while, and then
re-instantiate the object back when it recieves a new request?
Everytime the server re-instantiates the class, a new IndexSearcher instance will be
created. If the IndexSearcher.close() method does not release all the memory and the
server keeps unloading and re-instantiating the class, it will eventually hit the
OutOfMemoryError issue. The test program from my previous email is simulating this
condition. The reason why I instantiate/close the IndexSearcher inside the loop is to
simulate the scenario when the server unloads and re-instantiates the object. I think
that the same issue will happen if the application is written in servlet.
Although the singleton pattern may resolve the problem that I described above;
however, it isn't permitted by the J2EE spec according to some news letters. In order
words, I can't use singleton pattern in EJB. Please correct me if I am wrong on this.
Thanks,
Terence
> Reuse your IndexSearcher! :)
>
> Also, I think somebody has written some EJB stuff to work with Lucene.
> The project is on SF.net.
>
> Otis
>
> --- Terence Lai <[EMAIL PROTECTED]> wrote:
>
> > Hi All,
> >
> > I am getting a OutOfMemoryError when I deploy my EJB application. To
> > debug the problem, I wrote the following test program:
> >
> > public static void main(String[] args) {
> > try {
> > Query query = getQuery();
> >
> > for (int i=0; i<1000; i++) {
> > search(query);
> >
> > if ( i%50 == 0 ) {
> > System.out.println("Sleep...");
> > Thread.currentThread().sleep(5000);
> > System.out.println("Wake up!");
> > }
> > }
> > } catch (Exception e) {
> > e.printStackTrace();
> > }
> > }
> >
> > private static void search(Query query) throws IOException {
> > FSDirectory fsDir = null;
> > IndexSearcher is = null;
> > Hits hits = null;
> >
> > try {
> > fsDir = FSDirectory.getDirectory("C:\\index, false);
> > is = new IndexSearcher(fsDir);
> > SortField sortField = new
> > SortField("profile_modify_date",
> > SortField.STRING, true);
> >
> > hits = is.search(query, new Sort(sortField));
> > } finally {
> > if (is != null) {
> > try {
> > is.close();
> > } catch (Exception ex) {
> > }
> > }
> >
> > if (fsDir != null) {
> > try {
> > is.close();
> > } catch (Exception ex) {
> > }
> > }
> > }
> >
> > }
> >
> > In the test program, I wrote a loop to keep calling the search
> > method. Everytime it enters the search method, I would instantiate
> > the IndexSearcher. Before I exit the method, I close the
> > IndexSearcher and FSDirectory. I also made the Thread sleep for 5
> > seconds in every 50 searches. Hopefully, this will give some time for
> > the java to do the Garbage Collection. Unfortunately, when I observe
> > the memory usage of my process, it keeps increasing until I got the
> > java.lang.OutOfMemoryError.
> >
> > Note that I invoke the IndexSearcher.search(Query query, Sort sort)
> > to process the search. If I don't specify the Sort field(i.e. using
> > IndexSearcher.search(query)), I don't have this problem, and the
> > memory usage keeps at a very static level.
> >
> > Does anyone experience a similar problem? Did I do something wrong in
> > the test program. I throught by closing the IndexSearcher and the
> > FSDirectory, the memory will be able to release during the Garbage
> > Collection.
> >
> > Thanks,
> > Terence
> >
> >
> >
> >
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>
>
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