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Data centers are increasingly equipped with RDMAs. These network interfaces mark the advent of a new distributed system model where a node can directly access the remote memory of another. They have enabled microsecond-scale replicated services. The underlying replication protocols of these systems execute all operations under strong consistency. However, strong consistency can hinder response time and availability, and recent replication models have turned to a hybrid of strong and relaxed consistency. This paper presents RDMA replicated data types, the first hybrid replicated data types for the RDMA network model. It presents a novel operational semantics for these types that considers three distinct categories of methods and captures their re- quired coordination, and formally proves that they preserve convergence and integrity. It implements these semantics in a system called Hamband that leverages direct remote accesses to efficiently implement the required coordination protocols. The empirical evaluation shows that Hamband outperforms the throughput of existing message-based and SMR-based implementations by more than 4x.
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Exploiting Nil-Externality for Fast Replicated Storage
Do some storage interfaces enable higher performance than others? Can one identify and exploit such interfaces to realize high performance in storage systems? This paper answers these questions in the affirmative by identifying nilexternality, a property of storage interfaces. A nil-externalizing (nilext) interface may modify state within a storage system but does not externalize its effects or system state immediately to the outside world. As a result, a storage system can apply nilext operations lazily, improving performance. In this paper, we take advantage of nilext interfaces to build high-performance replicated storage. We implement SKYROS, a nilext-aware replication protocol that offers high performance by deferring ordering and executing operations until their effects are externalized. We show that exploiting nil-externality offers significant benefit: for many workloads, SKYROS provides higher performance than standard consensus-based replication. For example, SKYROS offers 3x lower latency while providing the same high throughput offered by throughput-optimized Paxos.
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- Award ID(s):
- 1838733
- PAR ID:
- 10299722
- Date Published:
- Journal Name:
- Proceedings of the Symposium on Operating Systems Principles
- ISSN:
- 0736-6663
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Conference Paper:
- The DOI is not currently available.
