Regarding CDB Data


As per my my understanding, CDB config data is preserved across Confd restarts by saving them and retrieving them from XML files. My intention is to utilize transaction and set-hooks to trigger a south-bound message from the application and this configuration is stored in CDB.

My question is two-fold:

  1. I was wondering if there was any way to invoke the same transaction or set-hook callbacks that were utilized to trigger the sound-bound message when CDB is restored with the configuration data from the XML files upon a restart?

  2. Is it possible to fetch a CDB element’s value(read operation) during the commit phase of a transaction for example in the create callback’s execution?

  1. sounds like a use case for cdb_trigger_subscription (or confd_cmd -c trigger_subscriptions, if you prefer to call it from a shell). But that would not invoke set-hook callbacks, only the CDB subscribers (I assume this is what you mean by “south-bound message”). I am not aware of any simple way to re-trigger data-provider callbacks.

  2. Yes, you can open a CDB session while processing the callback. Just be careful, the callbacks are supposed to react quickly.