'dropped due to full socket buffers' by SNMP

[Victor Gamov]

On 30/12/2020 12:57, Eugene Grosbein wrote:
> 30.12.2020 16:44, Victor Gamov wrote:
> 
>> Currently I'm thinking about ethernet flow control: Host-B connected to VLAN-750 on the third switch has 1G link (via igb driver)
>> and both Host-A and Host-B has fc=3.  So when Host-B get microburst it can send PAUSE and Host-A start to fill queue.
>> But FC disabled for all switches and I'm not sure about PAUSE can be propagated from Host-A to Host-B
> 
> AFAIK, pause frames are not forwarded. For short term you should make flow control settings consistent
> between link partners,

As I understand hw.ix.flow_control=3 to allow flow-control for 
negotiation.  Real PAUSE setting will be set during negotiation.  So 
where I can find active flow-control setting for host interface?

> maybe increase kern.ipc.maxsockbuf and then net.inet.udp.recvspace.

Eugene, at first message you suppose Host-A (sender) "outgoing link for 
that UDP packets is congested" because this host shows non-zero "dropped 
due to full socket buffers".   So is net.inet.udp.recvspace increasing 
on Host-B (mainly receiver) will be affected for this congestion?  Or I 
need to try to increase both kern.ipc.maxsockbuf and 
net.inet.udp.recvspace on both hosts?

Also how I can check current sockbuf usage?

> But for long term you should consider adding more links and create LACP aggregate
> so not input nor output link be close to congestion.

I'll migrate to 10G on Host-B at next month.


Thanks for your advise!

-- 
CU,
Victor Gamov