For 3.0.0 (T793)... For pcmk_cluster_t, we can replace all deprecated struct members except destroy() and cpg with a void *private member that can be used internally for a new internal struct containing the deprecated members.

In T788#12087, @kgaillot wrote:

Ah right, whenever we did this before, we used new value names as well. Let's define new names like pcmk_cluster_type_corosync. (Or maybe pcmk_cluster_layer/pcmk_cluster_layer_corosync.)

From crm/cluster.h, sbd uses send_cluster_text() and crm_msg_ais but only if HAVE_DECL_PCMK_CLUSTER_CLASSIC_AIS

I suspect the use case for this feature was being able to set an explicit value in one block of meta-attributes, then have another rule-based block of attributes that resets the value to the default. Simply omitting the meta-attribute from the rule-based block wouldn't cause the explicit value to be removed.

In T817#12112, @nrwahl2 wrote:

From the GitHub discussion:

I believe it was originally for testing the code paths. Not needed anymore

Optionally, we could have a (possibly hidden) --async-call option for developer use, that starts a mainloop and runs a callback function that processes the reply.

From the GitHub discussion: