Under heavy load, indexing may stop

The symptoms of this are an exception like this:

2004-02-05 14:39:25,765 ERROR [jira.issue.index.DefaultIndexManager] Problem with path d:\Jira\Index/issues: Lock obtain timed out
java.io.IOException: Lock obtain timed out
at org.apache.lucene.store.Lock.obtain(Lock.java:97)
at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:173)
at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:151)

Followed by many other exceptions like this:

2004-02-05 14:39:38,437 ERROR [jira.issue.index.DefaultIndexManager] Giving up reindex - waited 10 seconds
com.atlassian.jira.issue.index.IndexException
at com.atlassian.jira.issue.index.DefaultIndexManager.getIndexLock(DefaultIndexManager.java:409)
at com.atlassian.jira.issue.index.DefaultIndexManager.reIndexIssues(DefaultIndexManager.java:94)
at com.atlassian.jira.issue.index.DefaultIndexManager.reIndexIssues(DefaultIndexManager.java:83)
at com.atlassian.jira.action.component.ComponentDelete.doExecute(ComponentDelete.java:45)