Обсуждение: SLOWNESS ON JDBC INTERFACE

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SLOWNESS ON JDBC INTERFACE

От
"Debbie and Mike Meyer"
Дата:
I've been installing and learning the jdbc driver with 6.3.2.
The example programs in the ../postgresql/src/interface/jdbc
directory run fine -- except everyone takes a good two
minutes to execute.

Running in debug, the hangup is on this line:

[Loaded java/net/InetAddressImpl.class from
/usr/lib/jdk-1.1.5/lib/classes.zip]

It halts there for a couple of minutes then makes the connection
quickly.

It's jdk-1.1.5 from the Redhat RPM.  Redhat 5.0 upgraded
to kernel 2.0.35.  postmaster is running with tcpip ( -i option)
The connection is from localhost (127.0.0.1) and the pg_hba.conf is
left at default (with localhost permissions wide open).

It's only a P-75 on a hobby machine, but I think it shud
be more responsive.  Normal commands from within
psql work fine.

Anyone seen this problem or at least have some ideas
how to approach troubleshooting it?

Tks much for any help,

Mike Meyer

Re: [INTERFACES] SLOWNESS ON JDBC INTERFACE

От
Peter T Mount
Дата:
On Fri, 25 Sep 1998, Debbie and Mike Meyer wrote:

> I've been installing and learning the jdbc driver with 6.3.2.
> The example programs in the ../postgresql/src/interface/jdbc
> directory run fine -- except everyone takes a good two
> minutes to execute.
>
> Running in debug, the hangup is on this line:
>
> [Loaded java/net/InetAddressImpl.class from
> /usr/lib/jdk-1.1.5/lib/classes.zip]
>
> It halts there for a couple of minutes then makes the connection
> quickly.
>
> It's jdk-1.1.5 from the Redhat RPM.  Redhat 5.0 upgraded
> to kernel 2.0.35.  postmaster is running with tcpip ( -i option)
> The connection is from localhost (127.0.0.1) and the pg_hba.conf is
> left at default (with localhost permissions wide open).

I assume you mean the "host all 127.0.0.1" line is uncommented...

> It's only a P-75 on a hobby machine, but I think it shud
> be more responsive.  Normal commands from within
> psql work fine.

Even then it should be more responsive than that.

>
> Anyone seen this problem or at least have some ideas
> how to approach troubleshooting it?

All of the examples are written on a P133 Linux box, and they show no
problems of this nature.

I have seen this symptom on other systems (nothing to do with postgresql
or java), and it's either been caused by a routing or host lookup failure.

For example: At work, I have a large corporate unix machine. If a PC is
not in that machines /etc/hosts file, then there is a delay of 60-120
seconds before a connection is made.

PS: JDK 1.1.5 is ok for pre v6.4 versions of the driver. In 1.1.6, Sun
fixed a bug in the java.util.Date class, and v6.4 now handles dates how
they should be, so it can break on 1.1.5 or earlier. The earlier drivers
had to add a day when storing them in PreparedStatement.setDate()

Peter

--
       Peter T Mount peter@retep.org.uk
      Main Homepage: http://www.retep.org.uk
PostgreSQL JDBC Faq: http://www.retep.org.uk/postgres
 Java PDF Generator: http://www.retep.org.uk/pdf