1 đ„đ„ The Fire Down Below! đ„đ„Interoperable Convergence of Storage, Networking and Processing at Layer 2 đ„đ„ The Fire Down Below! đ„đ„ Micah Beck Electrical Eng. & Computer Sci. Terry Moore & Piotr Luszczek Innovative Computing Lab. University of Tennessee,Knoxville Dept of Energy Germantown 8/2/2017
2 Motivation and Background20 yrs: Web caches to prestage content (TN Cachebox) 15 yrs: Logistical Networking as async. communication Design methodology: follow patterns of Internet and Unix Architectural analysis: very confused, much controversy Experiment, deploy, describe⊠try, try, try to understand! Slow realization: storage, processing implement layer 3 Last year: some formal insight into the hourglass model
3 Interoperation and InnovationâWhat is lacking ⊠is a common, open, underlying âplatformâ, analogous to ⊠the Internet or Web, allowing applications and services to be developed as modular, extensible, interoperable components. To achieve the level of interoperation and innovation⊠that we have seen in the Internet will require investment in the basic research and development of an analogous open platform for intelligent infrastructureâŠ.â [CCC Smart Cities whitepaper]
4 Historical Context: Divergence of IT silosStarting with gates, wires and cores Modeled by Boolean operators and variables Divergence of communication, transformation, persistence Giving rise to networking, computation and storage silos But optimization & service creation work across silos Active Networking, Web Caching, Content Delivery Grid, Software Defined Networking This talk proposes an architectural strategy for convergence
5 Legacy Silos and Overlay Convergence
6 The Hourglass vs. The Anvil
7 Publications âOn the Hourglass Model, The End-to-End Principle and Deployment Scalabilityâ, Micah Beck, Submitted to CACM in 2016 (http://philsci-archive.pitt.edu/id/eprint/12626) âInteroperable Convergence of Storage, Networking and Processingâ, Micah Beck, Terry Moore and Piotr Lusczcek, Submitted to Usenix Middleware in (https://arxiv.org/abs/ )
8 Our Proposal: A common abstraction of the IT nodeConvergence can occur at many levels Operating system kernel interface (eg. file systems, sockets) Application overlay environments (eg. PVM, Grid, Workflows) Convergence at a high level preserves silo abstractions Reliability, performance, fairness, permanence, identity, accountability Convergence at a high level limits interop. and ubiquity Resources at the bottom of the stack are accessed through the top We propose a converged common abstraction of buffer management, transformation and transfer at layer 2.
9 Buffer Interoperability: Linux sendfile() system call
10 Interoperability: The spanning layerThe spanning layer as the basis of interoperability âCertain protocols are designed with the specific purpose of bridging differences at the lower layers⊠Such a layer is called a âspanning layerâ...â David. Clark, Interoperation, Open Interfaces, and Protocol Architecture, 1997 N interfaces require O(N2) translations, perhaps imperfect A common spanning layer enables ânetwork effectsâ The âthin waistâ of the hourglass âInteroperable convergenceâ: full generality, performance
11 Deployment Scalability: Simple, generic, limitedOvercoming barriers: technological, geographical, admin. Successful infrastructure interfaces scale âby designâ Not regulation or market dominance The strategy of the Internet: converge at a lower layer Expose underlying resources Enable flexibility and heterogeneity at higher layers Unix also followed a âloweringâ design strategy Saltzer, Clark, Reed, Thompson & Ritchie all worked on MULTICS Internet and Unix are the two examples of deployment scalability
12 Multics and Unix sure, but the Internet? End-to-end?âA similar problem exists for the magnetic tapes containing backup copies of segments. ⊠These tapes should probably be encrypted, using per-segment keys known only by the operating system.â âProtection and the Control of Information Sharing in Multicsâ, Jerome Saltzer, Massachusetts Institute of Technology Communications of the ACM, July 1974
13 Logical Weakness: The Hourglass Theorem (Beck 2016)Competing notions of âthinnessâ at the spanning layer âLogical weaknessâ may exert a controlling effect A weak spanning layer implies more implementations But a weak spanning layer implies fewer applications! Recipe for deployment scalability: Select ânecessary application requirementsâ Design the weakest spanning layer that satisfies them! Best effort, bounded lifetime, cycles, memory, block size, MTU, âŠ
14 Heterogeneity: Lowering the spanning layerOssification: The dark side of spanning layer ubiquity Necessary uniformity at the spanning layer Resources poorly exposed are not accessible IT nodes are computers: processors, storage, transfer In digital computer systems high level flow/process/file abstractions are implemented as sequences of buffer-to- buffer steps Minimal abstraction: operations on common buffer model
15 The Hourglass vs. The Anvil
16 Exposed Buffer ProcessingFundamental Buffer Management Local or in neighbor Weak: best effort with limits imposed by node owner Allocate/delete buffer lease Write/Read to/from/xfer-between buffer(s) Apply operation to transform buffer(s) Semi-static set of (weak, limited) operations available An operation can be a VM (taking code as input) â
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18 Application: Content DeliveryUnicast datagram delivery and point-to-multipoint services Redundant point-to-point transmissions Bottlenecks overload local network and server resources Poor user performance or denial of service (âSlashdot effectâ) Content Delivery employs caching & server replication A proprietary converged distributed platform âat application layerâ Specialized, expensive, difficult to deploy and operate Layering violation â an overlay built out of pieces of the Internet stack
19 Point-to-Multipoint Communication
20 Persistent processes vs. EBP opsmanager data movement ops
21 Application: Edge processingData deluge at the edge Sensors and many other distributed data producers Application-specific data volume reduction is required Thin clients require shared infrastructure Administration & policy are major roadblocks Trust, fair contention, cooperative sharing are enablers Remember: It works with LAN and OS resources
22 Example: Record filteringFILTER
23 Persistent processes vs. EBP opsfilter ops manager data movement ops
24 What about high level ârequirements?âSecurity: moats and bridges Low latency transmission Highly synchronized computation Permanent, corruption-free storage Identity and accountability, metering and billing Overlay implementation: The Data Logistics Toolkit, Lead PI Martin Swany, Indiana University (data-logistics.org).
25 Broader Implications and Generalized ConvergenceCommunicating with poor infrastructure Digital divide: rural, remote, urban, developing world, ⊠Disaster response: wildfire, floods, earthquakes, war, ⊠Can other resources & services inteoperate at layer 2? Power and transportation Smart Cities, Cyberphysical Systems, Critical Infrastructures, âŠ
26 WildfireDLN (Data Logistics Network)"Resilient System Solutions for Data Sharing for Wildland Fire Incident Operations," NIST Public Safety Accelerator Program Award #70NANB17H174 Lead PI Nancy French, Michigan Technical University
27 Conclusions Divergence is a historical artifact, not inevitableOptimization across silos is necessary but challenging Convergence at layer 2 is a path to generality, innovation Heterogeneity is key to flexible global services (layer 3) Locality of access enables control and flexibility
28 Thank you!