That brings back a few memories... There were a few bugs in the early versions of 10.x with regards to HSL... Upgrading to a later version (I think we went to 10.2.1 IIRC) resolved most of the issues.
There were a few other issues. Mainly around the way in which HSL is implemented.
- I believe that there is no buffering. If buffering would be required, then HSL opens another connection.
- There is no attempt to deliver HSL messages in order. Nor can you guarantee that two consecutive messages from the same thread will be delivered to the same HSL connection.
As I was after generating traffic stats more than being interested in individual messages, I ended up using tables to keep some of the stats for each connection and delivering them on a timer... That ramped up my performance considerably...
H