Datacenter Latency Control (DCLC) RG (Proposed)
Charter
Data centers are an example of network fabrics that enjoy high bandwidth, high path diversity, and very low end-to-end delays. These environments serve a large number of communicating systems - physical and virtual - that support workloads ranging from traditional applications (databases, email), VDI, to newer high connectivity applications such as hadoop. With very short response time and jitter requirements and applications in which large numbers of systems might simultaneously attempt to communicate with a much smaller set of machines, several problems are widely observed and commented on, including:
- Incast collapse: large numbers of latency-sensitive flows hit port-sharing shallow-buffered switches in a highly synchronized manner
- Bufferbloat: greedy bulk flows build up persistent queues at shallow buffered switches
- The impacts of multi-tenancy and the distribution of tenants across multiple data centers.
- Traffic management to SLAs, which may include guaranteeing minimum and maximum rates or latencies between systems or tenants in a data center application
- Virtualization complications: VM stack loses direct access to the physical link, while VM operation flows among hypervisors enter the competition. Also, Network Function Virtualization (which is to say, the containment of specified functionality within domains connected using tunnels or other virtual interconnects) can itself impose latency issues.
Solutions have been proposed at a variety of layers, including Ethernet (start/stop congestion control), IP (ECN), Transport (SCTP, TCP, DCTCP, MPTCP, UDP), and at the application layer (hadoop). The group proposes to first describe the characteristics of network fabrics and workloads found in data center, study the resulting problems and proposed solutions to determine the state of research on the topic, and then publish protocol standards and operational recommendations for the efficient high performance operation of data centers.
Chairs:
- 邓灵莉/Lingli Deng <denglingli@…>
- Fred Baker <fred@…>
Mailing List
dclc@… https://www.irtf.org/mailman/listinfo/dclc
