Tablelog in Distributed mode not getting updated

Hi,

Currently we are running LoadUI with Distributed Agents. we have around 6 Agents connected to controller. We run a load of around 100 TPS. The DUT (Device Under test) responds for sometime and after sometime say around 2 minutes there are lots of discard because the response time starts increasing. Even though there are discards there are some passed and failed transactions as well.
For the first few minutes we observe that the Tablelog is getting updated but after the discard starts the Tablelog stops updating the results. I understand that the tablelog may not be updated for the discarded requests but I expect the table log to get updated for Failed requests, which i don't see.

Also another question is on the maximum concurrent samples? I observe the Running requests reaches a maximum of 1000 * No of agents even if the maximum concurrent samples is configured as a large value (1000000000). Is there any restrictions on the maximum concurrent samples? Is there a way to increase it to maximum so that I will not see any discards?

Thanks in advance for your help.

Regards,
Raghu