JCO connections hanged in SMGW transaction at SAP

Question

Hi ,
I have deployed an ear application in SAP WAS 7.0 which basically talks to my SAP backend using JCO 2.1 connectors. The application will fetch the data from SAP backend calling FM using JCO 2.1.
I m using JCO pool manager and set to default 100 connections and taken care of release connections after every RFC call in finally block. The connections released successfully in  Dev and QA landscapes. In prod environment of customer, we are facing connections hang issues when it reaches to peak state of 100. It is due to max conversations reached at SAP backend, but the connections should eventually drop in SMGW which is not happening. There are some lost connections got hanged and remains for days and even they are not re-used. When i run method to release the pool, all connections are focibly returned back to pool, but lost connections still remain there.
Can somebody has similar situation ?
if connections reached to max in SMGW, will the connections from external client applications will get hanged ?
Does the JCO have control on the hanged connections if it reaches to max number?
Any help is appreciated!!!
Regards,
Ravi.

Answer 1

The relevant SAP note here is [549268|https://service.sap.com/sap/support/notes/549268].
But in this context there is big difference between the terms "not supported" and "does not work".
When SAP speaks of "not supported" this means that there won't be any SAP support for this configuration but this does not say anything about if this works technically. "Not supported" is more a legal issue than a technical one. SAP did not test this configuration and therefore also cannot guarantee to work.
Regarding JCo 2.1 I can say that technically it works with all Windows 32- and 64-bit versions. In contrast to that it really does not work with JRE releases >= 1.5 when using BCD types (type P) within your function modules.
From my point of view the connection issues don't have anything to do with the Windows version here.
And it is still not clear to me, if the maximum number of CPIC connections is reached at the AS ABAP/gateway side or the Java side. Furthermore it is not clear if these "hanging connections" were opened with your application at all or if they belong to another application.