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From Florian <f.allgoe...@web.de>
Subject Re: Customizing Sample Pinger of Uima
Date Mon, 06 May 2019 14:13:25 GMT
Hi,

is there eventual an example or demo for sending request to individual
service instances? I couldn't find an example in the repository.

Best regards,
Florian

On Mi, Mai 1, 2019 at 12:13 AM, Eddie Epstein <eaepstein@gmail.com>
wrote:
> Hi Florian,
>
> Interesting questions. First, yes the intended behavior is to leave 1
> instance running. Services are either started by having
> autostart=true, or
> by a job or another service having a dependency on the service.
> Logically
> it could be possible to let a pinger stop all instances and have the
> service still be in some kind of "running" state so that the pinger
> would
> continue running and be able to restart instances when it detected a
> need;
> all that is needed is a bit of programming :)
>
> A hacky approach would be not to use autostart, rather to start
> service-A
> by using a dummy service-B with a dependency on A. When service A
> pinger
> wants to stop A, it could issue a command to stop B which would allow
> service A to be stopped. Restarting A would require an external
> program
> requesting B to be started again.
>
> For the second question, the answer is yes for UIMA-AS services. The
> latest
> version of UIMA-AS supports sending process requests to specific
> service
> instances. A pinger could send such requests, and when an instance
> fails to
> reply the pinger can direct that instance to be stopped and another
> instance started. The answer is also yes for custom services for
> which the
> pinger knows how to address each instance.
>
> Regards,
> Eddie
>
> On Tue, Apr 30, 2019 at 1:43 PM Florian <f.allgoewer@web.de
> <mailto:f.allgoewer@web.de>> wrote:
>
>>  Hello everyone,
>>
>>  I have two questions about the given sample pinger example of Uima.
>>
>>  It is possible to set the minimal numbers of instances of a service
>> to
>>  zero? If I set the min-variable to zero uima is always starting a
>> new
>>  instance, when the last one is shutdown. Is this behavior intended
>> or
>>  is there a way to prevent the start of a new instance, when there
>> is no
>>  calls to the service? As we have some services that a rarely used,
>> we
>>  would only like to start instances on demand.
>>
>>  Secondly is there also a option to call specific instances of a
>> service
>>  and restart them? We would like to do health checks for individual
>>  instances and restart them if needed.
>>
>>  Best Regards
>>
>>  Florian
>>
>>
>>
>>


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