Casey_Lucas_167
Mar 25, 2014Nimbostratus
Transient data group failures from iRules
We're upgrading LTMs (9.2 to 11.x) and are converting/upgrading some iRules. When we did the original implementation years ago we had to put in some special logic because of transient failures when trying to access data groups from iRules. When the data group was accessed in the iRule at the same time the data group was being modified in the GUI (or via iControl), the iRule access would fail (as if the data group did not exist). For example, the following would fail:
when HTTP_REQUEST {
following line would fail if 'some_data_group' was being modfied via LTM GUI.
set preferredPool [findclass PREFERRED_POOL some_data_group " "]
}
My assumption at the time was that the data group modification was implemented with a complete delete followed by an insert vs an in-place modification.
We are now using
class
instead of findclass
and we have been unable to reproduce the transient problem of not being able to access a data group while modifying the data group. As it's difficult to disprove the existence of a problem, does anyone know if data groups are now (11.x) updated in an autonomous way? I.E. do iRules need to handle a missing data group because the data group is being updated?