Re: Severe performance degradation when using the 9.2-1000 JDBC 4 driver

On Fri, 19 Oct 2012, Craig Ringer wrote:

> On 10/19/2012 02:36 PM, Mikko Tiihonen wrote:
>>>> I think the DNS lookup is part of the JDBC failover connection patch
>>>> that I created. I initially used a InetSocketAddress.getHostString()
>>>> that does not do any DNS lookups, but since that method was added in
>>>> Java7 I had to revert to getHostName() method which does.
>>>>
>>>
>>> Is there any functionality that we need that is provided by using
>>> InetSocketAddress or is it just a convenient object to pass around host
>>> and port together? The simplest option to me seems to be reverting to
>>> passing simple strings/ints around (possibly in some kind of our own
>>> container).
>>
>> It is just a convenient container. And it seems on older JVMs it cannot be
>> used for such purposes.
>> I agree that we should just replace it with our own container that contains
>> the host/port pair.
>
> If that's all you're using it for, then that's the simplest and best choice.
> +1 from me on that.

Could the new container contain the localAddress (null for "any") as well
as the target host and port? I'm using a simple patch that allows binding
my JDBC connections to specific localAddress (unit tests & docs still
to-do), and I can envision scenarios where a client with multiple NICs
might need to initiate connections to failover hostA from localAddress X
and to failover hostB from localAddress Y, in environments where iptables
SNAT may not be an option.

By creating an appropriate factory class for this laddr/caddr/cport
container we could select the best implementation (Java7-only or
pre-Java7) in a static initializer and avoid having to resort to
reflection to avoid the unwanted DNS calls as discussed earlier in this
thread. Want me to take a stab at this this weekend? I'm not git-skilled
yet so I'll just have to email a patch.