On Fri, 19 Oct 2012, Scott Harrington wrote:
> 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.
Hi everyone, please look over this patch.
By introducing a simple org.postgresql.util.HostSpec to contain the
orignal caller-provided host and port, we never even need to call
InetSocketAddress.getHostName() or getHostString().
If this is accepted, then I will resubmit the localAddress patch based on
this; will be quite simple to put localAddress in HostSpec and then it's
available where needed at the time of Socket.connect in PGStream without
having to touch a dozen other constructor signatures to get it there.