Returning large lists in response to get_elem

CDB and CDB API
1

when large number (20k) of list items are returned as a list_element in response to get_elem() via confd_data_reply_value. confd is repeatedly calling get_elem() in an infinite loop. This is happening only when large number of entries are returned. Is there an upper limit on the list size?

2

Can you give an example of YANG structure (excerpt) covering the items, and an example of paths (input params) of the callbacks that you see repeated?

It’s a bit unclear what you mean, as get_elem is designated to a leaf, not lists of elements…

(“old” behavior of leaf-lists - if this is the case, has been updated to work in list-like style quite some time ago - around ConfD 6.4 if i recall correctly)

3 
container test {
    leaf model {
        tailf:callpoint extract_device_model;
        type string;
    }
}

I’m returning a leaf-list which has around 40k entries from callpoint extract_device_model, even after returning all 40k entries as part of
the callpoint, confd still calls get_elem() multiple times which results
in callpoint being called multiple times and the cli just gets stuck.

4

See the examples.confd/dp/generic_perf example and the ConfD-Demos/dp-performance at master · ConfD-Developer/ConfD-Demos · GitHub demo for data provider application performance guidance and a reference example.
Regarding leaf-lists, search for “CS_NODE_IS_LEAF_LIST” in ConfD-Demos/cdboper_dp.c at master · ConfD-Developer/ConfD-Demos · GitHub
Ps. your YANG model above contains a leaf, not a leaf-list.

5

Thanks for the response.

I have a requirement to return 70K elements as a leaf-list in response to get_elem. Is this possible? Is there any hard limit on how many elements a leaf-list can have?

6

Memory in your system is the only limit with ConfD.

Since you say the get_elem() callback is invoked for leaf-list I am guess you are either using a very old ConfD or the long time deprecated CONFD_DAEMON_FLAG_LEAF_LIST_AS_LEAF flag.

As you describe ConfD is calling get_elem() in an “infinite loop”, check your developer log (with log level trace) for clues.