I found the best approach was with pythonbind:

import intersys.pythonbind3 as pyb

url = "localhost"
userName= "???"
password="???"
port=1972

def main():
        conn     = pyb.connection()
        version = conn.get_implementation_version()
        conn.connect_now(f'[{url}][{port}]:%SYS', userName, password,None)

        # Create objects used to access cache/iris
        db  = pyb.database(conn)
        qry    = pyb.query (db)
        obj    = pyb.object(db)

......

With the connection handle and the db, qry, obj objects you can use the methods and classes to access any database item in the cache database

Ok, trying to isolate my syntax error. I have re-reviewed the class specs but I am not seeing an issue. I have this:

    allocated = 0
    used      = 0
    db          = "/data/testdb/"
    global      = "STRELPERF"
    
    # Set args to pass by reference
    list = [db,global,allocated,used]

    # exec the class method to get the global size
    res = self.db.run_class_method("%Library.GlobalEdit", "GetGlobalSize",list)

This is the call that returns the failure status of res(0,). The associated error text is :

ERROR #00: (no error description)

Since for other databases that do not contain the global I get the error:

ERROR #308: Global STRELPERF not found.

It seems that code clip is close but something that I am not seeing is missing. Any help would be appreciated.