Strange performance woes

[Serge Knystautas <se...@lokitech.com>]

I noticed that James was slow retrieving large (>1 meg) binary data through
my JDBC driver.  After many hours of testing, I was able to conclude that I
am missing something significant, and it's really slowing James down.
Perhaps someone can get me pointed back in the right direction.

Environment A is James (latest in CVS) running as a service in Avalon
(snapshot mid-September).
Environment B is a Resin webserver (cmp 1.0.4).
Environment C is a test class run from the command line

All are running on the same box (P3 800 Win2k 256 megs ram) with the same
JVM (Sun 1.3.0-C w/hotspot).  All are set to run initial heap size at 16m
(-Xms) and max heap size at 64m (-Xmx).  I'm using inetsoftware's TDS driver
to connect to a MS 2k SQL Server over a switched 100mbit LAN.

I time the following code:

for (int i = 0; i < 10; i++) {
  long start = System.currentTimeMillis();
  PreparedStatement stmt = conn.prepareStatement("select message_body from
messages where message_name = ?");
  stmt.setString(1, "mymessagesname");
  ResultSet rs = stmt.executeQuery();
  rs.next();
  byte[] data = rs.getBytes(1);
  rs.close();
  stmt.close();
  System.err.println(System.currentTimeMillis() - start);
}

Here are the results for a message that is 1,190,306 bytes:
Environment A (james/avalon): between 26,508 ms and 32,937 ms
Environment B (resin/jsp): between 3,465 ms and 5,087 ms
Environment C (commandline): between 3,645 ms and 3,935 ms

I tested that all had similar Runtime.totalMemory and freeMemory settings
and the current thread's priority said it was 5... I've tried modifying
Avalon's run.bat to tweak different settings, but nothing seems to make a
difference.

Any thoughts?

Serge Knystautas
Loki Technologies - Unstoppable Websites
http://www.lokitech.com/


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