If you are running with a Sun JVM 1.6, one possible way is to monitor the low level JVM java IO calls using BTrace (See http://kenai.com/projects/btrace/pages/Home). This is kind of lightweight custom java profiler. It's quite easy to setup but will require that you know what IO calls are involved to write a few java lines to track what you need to.
For example to track the reads calls start/end including the duration: @OnMethod(clazz = "java.io.RandomAccessFile", method = "read") public static void onRandomReadStart() { print(timestamp("y/M/d HH:mm:ss.SSS")); print(strcat(", ", name(currentThread()))); print(strcat(", ", "IO read start"); } @OnMethod(clazz = "java.io.RandomAccessFile", method = "read", locati...@location(value=Kind.RETURN)) public static void onRandomReadEnd(@Duration long d) { print(timestamp("y/M/d HH:mm:ss.SSS")); print(strcat(", ", name(currentThread()))); print(strcat(", ", str(d)); print(strcat(", ", "IO read end"); } -----Original Message----- From: Jason Rutherglen [mailto:jason.rutherg...@gmail.com] Sent: jeudi 3 juin 2010 20:13 To: java-user@lucene.apache.org Subject: Monitoring low level IO This is more of a unix related question than Lucene specific however because Lucene is being used, I'm asking here as perhaps other people have run into a similar issue. On an Amazon EC2 merge, read, and write operations are possibly blocking due to underlying IO. Is there a tool that you have used to monitor this type of thing? --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org