+cc Barry, who is the expert in this area, for his thoughts. Do you have the complete list of TM config calls you issue to set this up? I know Bala (+cc) was looking to propose a "streamlined" config API for TM since this is can be tricky as there are a number of "knobs" the TM provides to control these things.
You are correct that the TM only really gets involved when output classes become over-subscribed as its job is to throttle output based either on physical or configured transmission limits. So without seeing the complete config it's difficult to assess what might be going on here. On Fri, Apr 28, 2017 at 8:57 AM, Oriol Arcas <or...@starflownetworks.com> wrote: > Hello, > > I'm trying to use the Traffic Manager to implement priorities and weights. > But it is not applying these policies. > > I have observed from the traces that the TM is not queuing the packets, but > directly ouputing them. For instance, see this final stats from the TM: > > odp_tm_stats_print - tm_system=0x56347C6E6790 tm_idx=0 > input_work_queue size=256 current cnt=0 peak cnt=256 > input_work_queue enqueues=1225767 dequeues=1225767 fail_cnt=1034 > green_cnt=0 yellow_cnt=0 red_cnt=0 > * queue_num=1 priority=0 rcvd=408650 enqueued=0 dequeued=0 > consumed=408650 > * queue_num=2 priority=0 rcvd=409041 enqueued=0 dequeued=0 > consumed=409041 > * queue_num=4 priority=2 rcvd=408076 enqueued=0 dequeued=0 > consumed=408076 > > I have two priorities (0 and 2) and 3 queues. Two queues go to priority 0, > with 30% and 70% weights. I transmit 1GB through each queue with TCP. There > is no prioritization, nor weighted scheduling. > > My understanding is that if the TM doesn't enqueue the packets in its > internal queues (enqueued and dequeued stats are 0), it doesn't apply any > of the algorithms (priority encoder, WFQ, etc.). > > I am using taps in my laptop, not a real network, so the BW is quite high > (~3 Gbps). Could it be that if the network can absorb the BW processed by > the CPU, then the PKTOUT doesn't get congested and no queing is done, so no > TM either. > > However, to reject this hypothesis, I reduced the main input queue to 256 > packets. Now, it gets full, because the TM rejects 1034 packets. So it > still doesn't apply queuing (thus priorities and weights), but it is > clearly congested because it rejects packets. > > Any thoughts on this? > > Thank you in advance. > > -- > Oriol Arcas > Software Engineer > Starflow Networks >
