Errata

The sentence says "Its purpose is to provide interoperability (connectivity, data mapping, and routing) combined...", but it should be "...interoperability (connectivity, data TRANSFORMATION, and routing) combined..." as noted on page 48 and on page 296 glossary: ESB.

Note from the Author or Editor:
accept as proposed, thus:
in the 2nd list item:
s/data mapping/data transformation/

Replace "in the opposite order" by "in the opposite direction"

Of course, the service should have the customer id as an additional parameter, which has to be used internally to identify the customer.
Thus, the code should be as follows
(custID 5 times with or without comma added)
:

string changeAddress (custID, newAddress)
{
oldAddress = backend_1.getAddress(custID);

status = backend_1.changeAddress(custID,newAddress);
if (status == failure) {
return "couldn't modify address in backend 1";
}

status = backend_2.changeAddress(custID,newAddress);
if (status == failure) {
// compensation: restore old address to keep consistency
status = backend_1.changeAddress(custID,oldAddress);
if (status == failure) {
fatalError(...);
}
return "couldn't modify address in backend 2";
}
return "OK";
}

In addition, use proportional font for the ellipsis (...) in the listing.

Note from the Author or Editor:
please care for exact indents.
Keep them just as they are.
Just add "custID" or "custID," 5 times.
Just use proportional font for ellipsis.

last line but 1:
s/setContractData()/getContractData()/

both in code at the top and Figure 18-13:
the order of
lastname
and
isActive
should be reversed.

Note that Figure 18-13 is a screen dump by me (the author),
so you probably need an update for that by me.