JCO3 JCoDestination property

Question

Hi,
  Can someone please shed some more light on below properties applicable to JCoDestination. The documentation does not provide much detail
jco.destination.peak_limit      Maximum number of active connections that can be created for a destination simultaneously
jco.destination.pool_capacity      Maximum number of idle connections kept open by the destination. A value of 0 has the effect that there is no connection pooling.
jco.destination.expiration_time      Time in ms after that the connections hold by the destination can be closed
jco.destination.expiration_check_period     Period in ms after that the destination checks the released connections for expiration
My requirement is to always have a pool capacity of 1,max limit of 1 with expiration time of say 300 seconds. However with this configuration I do see no physical socket connection opened is more than 1 (>max_limit).
What should be the best configuration to achieve the above requirement??

Answer 1

As a starter it might be best to take try out the examples that ship with the JCo3 distribution. I cannot comment much on your code, as it's an excerpt and doesn't show everything. E.g. I have no clue what the line this.getDestination().getAttributes() means; usually you retrieve destinations via the class JCoDestinationManager and there you always have to at least provide the name of the destination.
So let me give some generic comments instead:
<ul style="list-style:circle">
<li>Properties for destinations can be returned via a class that implements the interface DestinationDataProvider; you can register your own implementation (once) via static method Environment.registerDestinationDataProvider().</li>
<li>SAP ships the JCo with a generic file handler for providing destination attributes: It basically searches in the current directory (i.e. from where you started your application) for client destinations with the given name and extension ".jcoDestination" (server destinations use extension ".jcoServer"). As far as I remember you can also change the directory where those destination property files are searched for by setting System property "jco.destinations.dir".</li>
<li>I strongly recommend registering your own DestinationDataProvider (or ServerDataProvider) and so does SAP; this is especially true if you get your properties from somewhere else (as it seems to be in your case) or want some specific processing (e.g. use encrypted passwords in your properties that you decrypt upon loading).</li>
<li>For troubleshooting your existing coding I'd verify that you did actually create the file with the properties and that the file name (without the extension) matches the name that you use when trying to retrieve the destination.</li>
</ul>
Cheers, harald