Currently northd incremental processing fails when logical routers are added/removed. The I-P node dependency is:
NB.Logical_Router -> en_northd -> en_lflow
When a new router is created/deleted the "en_northd" input handler for logical routers is called:
bool northd_handle_lr_changes(const struct northd_input *ni, struct northd_data *nd) { const struct nbrec_logical_router *changed_lr; NBREC_LOGICAL_ROUTER_TABLE_FOR_EACH_TRACKED (changed_lr, ni->nbrec_logical_router_table) { if (nbrec_logical_router_is_new(changed_lr) || nbrec_logical_router_is_deleted(changed_lr)) { goto fail; } ... fail: destroy_northd_data_tracked_changes(nd); return false; }
which in turn causes "en_lflow" handler for en_northd data changes to fail:
bool lflow_northd_handler(struct engine_node *node, void *data) { struct northd_data *northd_data = engine_get_input_data("northd", node); if (!northd_has_tracked_data(&northd_data->trk_data)) { return false; } ...
This triggers a full recompute of the "en_lflow" node which can be costly at scale.