InetAddress should utilize networkaddress.cache.ttl for getLocalHost() too

[Deven You]

Hi Michael,

Thanks for your review, I have updated the patch[1] according to your 
comments.

[1] http://cr.openjdk.java.net/~youdwei/ojdk-527/webrev.03/ 
<http://cr.openjdk.java.net/%7Eyoudwei/ojdk-527/webrev.02/>

Thanks a lot!
On 07/25/2012 11:19 PM, Michael McMahon wrote:
> On 24/07/12 07:17, Deven You wrote:
>> Hi Alan and Michael,
>>
>> I add a java doc[1] for the new networkaddress.cache.localhost.ttl 
>> property. Please take a look when you have time.
>>
>
> The change looks fine to me. There is a typo in the apidoc in InetAddress.
> "as as" should be "as an". Might as well correct the same mistake in 
> the previous
> paragraph also.
>
> Since this is a spec change, it will need a CCC request. Is there a 
> bug id for this issue?
>> Again, I don't know how to set 
>> cachePolicyPropFallback/negativeCachePolicyPropFallback. Any 
>> suggestion please tell me.
>>
>
> These are system properties. So, they are normally set on the command 
> line with java -Dsun.net.inetaddr.ttl=X ....
>
> - Michael.
>
>> [1] http://cr.openjdk.java.net/~youdwei/ojdk-527/webrev.01/ 
>> <http://cr.openjdk.java.net/%7Eyoudwei/ojdk-527/webrev.01/>
>> Thanks a lot!
>>
>> On 07/12/2012 02:59 PM, Deven You wrote:
>>> Hi Alan and Michael,
>>>
>>> Thanks very much for your kind suggestions.
>>>
>>> I agree that local host shouldn't follow the default caching 
>>> mechanism because the IP may change frequently. And I also think 
>>> making the cache time configurable is a better solution.
>>>
>>> I am willing to make these changes including adding the local host 
>>> caching mechanism into the java doc.
>>>
>>> I have gone through the related code for InetAddress.java and 
>>> InetAddressCachePolicy.java. And I think we could add a new security 
>>> property networkaddress.cache.localhost.ttl to achieve the goal.
>>>
>>> As far as I know, to add networkaddress.cache.localhost.ttl I need 
>>> change jdk/src/share/lib/security/java.security*(include 
>>> java.security, java.security-solaris, java.security-macosx and 
>>> java.security-windows). Please correct me if I have any 
>>> misunderstanding.
>>>
>>> Here I have one question need your help:
>>>     the static block in InetAddressCachePolicy.java will first try 
>>> to get cachePolicyProp/negativeCachePolicyProp from System 
>>> properties. If one of the cache values is null then the value of 
>>> cachePolicyPropFallback/negativeCachePolicyProp would be got from 
>>> System properties.
>>>    I don't know where we declare these fallback properties so I have 
>>> no idea where I can do the same thing for 
>>> networkaddress.cache.localhost.ttl.
>>>
>>> Please take a look.
>>>
>>> Thanks a lot!
>>>
>>>
>>> On 07/11/2012 06:55 PM, Michael McMahon wrote:
>>>> On 11/07/12 08:00, Alan Bateman wrote:
>>>>> On 05/07/2012 07:10, Deven You wrote:
>>>>>> Hi All,
>>>>>>
>>>>>> I noticed that InetAddress.getLocalHost() uses cache to improve 
>>>>>> the performance. However the default implementation is caching 
>>>>>> local host within 5 seconds.
>>>>>>
>>>>>> From the spec, networkaddress.cache.ttl should be used to control 
>>>>>> the cache behaviour and I think it is a better solution.
>>>>>>
>>>>>> For example, if the networkaddress.cache.ttl is set to -1 which 
>>>>>> means always cache the local host then we can avoid unnecessary 
>>>>>> operations on getAddressesFromNameService to improve the performance.
>>>>>>
>>>>>> I have made a patch for this solution, so anyone would like to 
>>>>>> take a look?
>>>>>>
>>>>>> [1] http://cr.openjdk.java.net/~littlee/OJDK-527/webrev.00/ 
>>>>>> <http://cr.openjdk.java.net/%7Elittlee/OJDK-527/webrev.00/>
>>>>>> Thanks a lot!
>>>>>> -- 
>>>>>> Best Regards,
>>>>>>
>>>>>> Deven
>>>>> I'm not sure about this one as I suspect it will cause problems in 
>>>>> DHCP or any environments where the host addresses changes, say 
>>>>> moving to a different wireless network or waking up a machine 
>>>>> after hibernation.
>>>>>
>>>>> -Alan
>>>>
>>>> That's true. We updated the spec for the caching behavior a while 
>>>> back, and probably should have included this exception
>>>> for the local host. I agree that we shouldn't change the behavior. 
>>>> Perhaps, the 5 seconds could be configurable itself,
>>>> but I think it should be kept separate from the main caching behavior.
>>>>
>>>> - Michael.
>>>>
>>>
>>>
>>> -- 
>>> Best Regards,
>>>
>>> Deven
>>
>>
>> -- 
>> Best Regards,
>>
>> Deven
>


-- 
Best Regards,

Deven

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.openjdk.java.net/pipermail/net-dev/attachments/20120731/3f309ec5/attachment.html