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From "mike bell (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-3106) securityMechansim=8 causes slowdown on some JVMs?
Date Sun, 16 Aug 2009 01:47:14 GMT

    [ https://issues.apache.org/jira/browse/DERBY-3106?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12743798#action_12743798

mike bell commented on DERBY-3106:

Kathey thanks. I've not had time to play with this for a long time, but as I recall at the
time Derby was

a) client ser ver
b) not connection pooled (that's been resolved of course)

As I recall, I did run that JSP in a loop a few times, and it didn't really matter. There
were many JSP pages in the product that used Derby Connections (unpooled at the time), and
nearly all slowed down. The slowdown was only noticeable after the first connection/creation,
and then shutdown of the webapp. From then on, it was SLOW.

I am surprised that while you were able to dupe a noticeable slow down ( 4.9 s vs .63 s with
encryptiion on IBM vs SUN), but I had at the time an ever more dramatic slowdown of 80s. Admittedly
this was with IBM JVM 1.42.\

Anyway, just sharing my memories, for FWIW for whoever might grab this one

> securityMechansim=8 causes slowdown on some JVMs?
> -------------------------------------------------
>                 Key: DERBY-3106
>                 URL: https://issues.apache.org/jira/browse/DERBY-3106
>             Project: Derby
>          Issue Type: Bug
>          Components: Network Client
>    Affects Versions:
>         Environment: IBM JVM 1.42, SLES 10 or SLES 10 SP1
>            Reporter: mike bell
>         Attachments: goo.java, goo.jsp
> 1. We have a Web App that uses Derby 10.2, doing client/server. It is a Java 1.4 app
> 2.  We run it extensively on Windows (JDK 1.4,1.5/Tomcat 4.1/5.5), SLES 9, SLES 10, OES,
and NetWare
> 3. Recently I added securityMechanism=8 to the JDBC URL to at least encrypt the password
(it's all local right now, but it was a nicety). Extensive testing on Windows proved flawless.
> 4. Immediately after releasing to Beta testers, we heard the "UI" was slow. I traced
this specifically to pages that accessed Derby Connections (or built them into a pool - there
are depressing reasons why we don't do this all the time currently).
> 5. The issue only occurs on SLES 10/10 SP1. It occurred for about 80% of users, and was
oddly intermittent. The slowdown did NOT occur on initial login, but after they added some
entries (adding some fields to some tables effectively). From then on, the slowdown was rampant
and survived restarts. Even the login (which queries some DBs) was very very slow
> 6. A test JSP page was created, which basically will be attached, but did nothing more
than create a Connection, do a simple query, iterate the result set. Then do the same thing
without the security Mechanism. Then spit out benchmark numbers.
> On my box (Windows), the numbers were typically a total of less than 10 ms for the queries.
On machines exhibiting the issue, they were 80 SECONDS!
> As soon as the securityMechanism=8 was removed, the issue disappeared.
> Now, I'm not really sure I should blame Derby. My offhand gut guess is there is something
wrong with the IBM JVM 1.42, doing the encrypted password and Derby  took a long time to timeout
and then backed down to cleartext..
> But I don't have a lot of time to test this one out. So I'm mostly posting FYI.
> (Additional: Connection logging was performed and not that interesting. Telnet to derby
server was quick - it appears it is all in the client negotiating the connection that the
slow down occurs).

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