NotifyType.NT_FILL_ARRAY_WITH_COLUMN (220)
vs
NotifyType.NT_FILL_ARRAY_WITH_COLUMN_ONLY_UPDATES (336)
What's the difference between them?
What's the history of 336? Is it related to the incorporation of Protocol.Clear and Protocol.Leave?
Hi,
To give an overview of the history: More than a decade ago the EPM (CPE) collectors were using NotifyProtocol NT_FILL_ARRAY_WITH_COLUMN (220) to fill in the data that was being polled in the frequency tables. But as the number of US and DS channels increased with the introduction of newer DOCSIS version this meant that the tables also needed to contain more rows and the processes could not handle the data load anymore at that moment in time. For this reason the NT_FILL_ARRAY_WITH_COLUMN_ONLY_UPDATES (336) got introduced as a more performant alternative for the notify 220: only the cells that changed got forwarded in the background and because of that there was an increase in the throughput as it could save out some locking (you still had to fill in the cell value in the notify, but if it was the same then it got filtered out in the background).
Later on, the internal locking in the DataMiner core software got rewritten and it could be improved in such a way that there was no difference anymore between the notify 220 and 336. So now there is no difference between notify 220 and 336, they're both the same.
This is something different with the protocol.Clear and protocol.Leave that got introduced later. With these items you indicate protocol.Clear = set the cell to not initialized, protocol.Leave = I don't know what the cell value is, but the value can stay as is. In the past when using the notify one had to fill in all the values even though they were to remain the same.
Do note that at this moment a protocol.Leave in the background will copy the current cell value and fills it in as if you would have filled it in the notify call, this result is then being forwarded to other processes like SLElement so that process is not aware if a protocol.Leave or a real value was specified. There were plans to ignore the .Leave cell but as far as I'm aware this is not implemented yet. In other words when executing a notify with a row containing protocol.Leave for all the columns will be better performance wise to leave out that row from the notify.