Crossbow is another cool technology on Opensolaris. It gives administrator control over network resources and is an important mechanism in managing service level. Administrator could decide how much bandwidth to allocate to the different containers using different vnics.
At the Singapore OpenSolaris User Group Event today, we had a good discussion on this technology. We also configured flow control on the vnic and tested how the maxbw parameter affect network throughput.
First, a 10MB file is created on my notebook. We coped the 10MB file using scp from one zone to another, using different maxbw setting. The result was:
1. maxbw=5, 24 secs
2. maxbw=2, over 1 minute
3. maxbw=10, 10 secs
The results shows that changing the maxbw parameter does impact the throughput of the vnic.
With this capability, administrator could give more bandwidth to applications that require quick response or are time critical to meet service level requirement.