• Reading Group. Performance-Optimal Read-Only Transactions

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    Last meeting we looked at “Performance-Optimal Read-Only Transactions” from OSDI’20. This paper covers important topics of transactional reads in database/data-management systems. In particular, the paper discusses “one-shot” read-only transactions that complete in 1 network round-trip-time (RTT) without blocking and bloated and expensive messages. If this sounds too good to be true, it is. Before presenting…

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  • Reading Group. Microsecond Consensus for Microsecond Applications

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    Our 43rd reading group paper was about an extremely low-latency consensus using RDMA: “Microsecond Consensus for Microsecond Applications.” The motivation is pretty compelling — if you have a fast application, then you need fast replication to make your app reliable without holding it back. How fast are we talking here? Authors go for ~1 microsecond…

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  • Reading Group. Cobra: Making Transactional Key-Value Stores Verifiably Serializable.

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    This Wednesday, we were talking about serializability checking of production databases. In particular, we looked at the recent OSDI’20 paper: “Cobra: Making Transactional Key-Value Stores Verifiably Serializable.” The paper explores the problem of verifying serializability in a black-box production system from a client point of view. This makes sense as serializability is an operational, client-observable…

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  • Reading Group. A large scale analysis of hundreds of in-memory cache clusters at Twitter.

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    In the 41st distributed systems reading group meeting, we have looked at in-memory caches through the lens of yet another OSDI20 paper: “A large scale analysis of hundreds of in-memory cache clusters at Twitter.” This paper explores various cache usages at Twitter and distills the findings into a digestible set of figures. I found the…

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  • Reading Group. Virtual Consensus in Delos

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    We are continuing through the OSDI 2020 paper list in our reading group. This time we have discussed “Virtual Consensus in Delos,” a consensus paper (Delos is yet another greek island to continue the consensus naming tradition). Delos relies on the log abstraction to keep track of all commands/operations and their order. Traditionally, some consensus…

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  • Planetary-Scale Systems Seminar Spring 2021

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    This spring semester I am teaching an exciting seminar class: “Planetary-Scale Systems.” I will start the seminar with a 4 lectures long crash course to get my students on the same page, but the bulk of the class will be paper presentations and discussions. The format is similar to the zoom reading group I am…

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  • Reading Group. hXDP: Efficient Software Packet Processing on FPGA NICs

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    Last reading group meeting we have discussed “hXDP: Efficient Software Packet Processing on FPGA NICs.” This paper talks about using FPGA NICs to offload some CPU cycles doing certain routine packet processing tasks. In particular, the paper implements XDP purely in FPGA and achieves a performance similar to that of a single x86 CPU core.…

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  • Reading Group. Toward a Generic Fault Tolerance Technique for Partial Network Partitioning

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    Short Summary We have resumed the distributed systems reading group after a short holiday break. Yesterday we discussed the “Toward a Generic Fault Tolerance Technique for Partial Network Partitioning” paper from OSDI 2020. The paper studies a particular type of network partitioning – partial network partitioning. Normally, we expect that every node can reach every…

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  • Reading Group. Near-Optimal Latency Versus Cost Tradeoffs in Geo-Distributed Storage

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    Short Summary Yesterday we discussed Pando, a geo-replication system achieving near-optimal latency-cost tradeoff in storage systems. Pando uses large Flexible Paxos deployments and erasure coding to do its magic. Pando relies on having many storage sites to locate sites closer to users. It then uses Flexible Paxos to optimize read and write quorums to have…

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  • Reading Group. Autoscaling Tiered Cloud Storage in Anna.

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    This week we looked at “Autoscaling Tiered Cloud Storage in Anna.” This is the second Anna paper. The first one introduces Anna Key-Value store, and the second paper talks about various “cloud-native” improvements. The presentation by Michael Whittaker is available here: Short Summary Anna is an eventual-consistent key-value data store, where each value is a…

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Aleksey CharapkoI am an assistant professor of computer science at the University of New Hampshire. My research interests lie in distributed systems, distributed consensus, fault tolerance, reliability, and scalability.
X (twitter)@AlekseyCharapko
emailaleksey.charapko@unh.edu

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