RE: ENRP Server Hunt Timer

Thomas Dreibholz <mailto:[email protected]> wrote:
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> On Friday 29 October 2004 00:25, Johnson Walter-CWJ002 wrote:
>> Currently the draft states in ENRP server hunt procedure of section
>> 3.6 bullet item SH5 on page 21 that
>> 
>> SH5) If the T5-Serverhunt timer expires the following should be     
>> performed: 
>> 
>>       SH5.1) The endpoint MUST double the value of the T5-Serverhunt
>>       timer. SH5.2) The endpoint SHOULD stop the establishment of
>>       associations          and connections. SH5.2) The endpoint
>>          SHOULD repeat trying to establish an association or
>>          connection by proceeding to step SH1.  It SHOULD attempt to
>> select a different set of transport addresses to          connect
>> to.  
>> 
>> Currently the T5-Serverhunt timer keeps on doubling and there is no
>> upper limit on this so it appears it could go on forever. It would
>> seem reasonable to add a ceiling on the max value that the
>> T5-Serverhunt can reach (e.g. a variable max.severhunt.value to
>> section 5.1) or place to place a threshold of attempts to make called
>> MAX-SERVER-HUNTS in section 5.3. If either max is reached, a signal
>> could be sent to an ASAP application of the failure to find a home
>> ENRP server.
> 
> An upper limit for doubling the timeout is useful.
> 
> But it may be useful to keep on trying to connect to a NS even when
> the maximum timeout has been reached, because it may be better for the
> application to wait instead of failing. For this case, the number of
> trials must also be limited (this could be a configuration option, to
> be set by the application - I have implemented this behavior in the
> rsplib prototype). 
> 
> Example:
> TimeoutLimit=4s
> MaxTrials=100
> 
> Trail #1: timeout=1s
> Trail #2: timeout=2s
> Trail #3: timeout=4s (no more doubling)
> Trail #4: timeout=4s
> ...
> Trail #100: timeout=4s  => After this trial, signal failure to the
> user. 
> 


I agree with your proposal above.