HDR Parameters and their Meaning

DRTIMEOUT

DRTIMEOUT specifies the upper limit of time that the Primary will wait for an acknowledgment from the Secondary until it assumes a data replication failure. Checkpoints on the Secondary must not exceed the DRTIMEOUT boundary. Primary and Secondary will also ping each other regardless if logical log records are send. DRTIMEOUT specifies the interval at which those pings are send. A HDR failure is assumed after four sequential ping attempts failed. So the DRTIMEOUT parameter should be set to 1/4 (25 %) of the total time that is appropriate before declaring a failure.

Starting HDR and using only level-0 backup vs (currently not implemented) using level-0 with incremental backups

For physical restore secondary of HDR, level-0 must be using. If you are using incremental backups from primary for physical restore on secondary, you get the error on secondary IDS in online.log:

...
11:55:36 DR: new type = secondary, primary server name = hdr_lo
11:55:36 DR: Trying to connect to primary server = hdr_lo
11:55:38 DR: Secondary server restored from a non level-0 archive - aborting
11:55:39 IBM Informix Dynamic Server Stopped.
...

Why IBM does not fix this behavior for possibility using incremental backups for physical restore secondary HDR?