Results 1 -
6 of
6
Logic and Lattices for Distributed Programming
"... In recent years there has been interest in achieving application-level consistency criteria without the latency and availability costs of strongly consistent storage infrastructure. A standard technique is to adopt a vocabulary of commutative operations; this avoids the risk of inconsistency due to ..."
Abstract
-
Cited by 21 (2 self)
- Add to MetaCart
(Show Context)
In recent years there has been interest in achieving application-level consistency criteria without the latency and availability costs of strongly consistent storage infrastructure. A standard technique is to adopt a vocabulary of commutative operations; this avoids the risk of inconsistency due to message reordering. Another approach was recently captured by the CALM theorem, which proves that logically monotonic programs are guaranteed to be eventually consistent. In logic languages such as Bloom, CALM analysis can automatically verify that programs achieve consistency without coordination. In this paper we present Bloom L, an extension to Bloom that takes inspiration from both of these traditions. Bloom L generalizes Bloom to support lattices and extends the power of CALM analysis to whole programs containing arbitrary lattices. We show how the Bloom interpreter can be generalized to support efficient evaluation of lattice-based code using well-known strategies from logic programming. Finally, we use Bloom L to develop several practical distributed programs, including a key-value store similar to Amazon Dynamo, and show how Bloom L encourages the safe composition of small, easy-to-analyze lattices into larger programs.
Blazes: Coordination analysis for distributed programs,”
- EECS Department, UC Berkeley, Tech. Rep.
, 2013
"... Abstract-Distributed consistency is perhaps the most discussed topic in distributed systems today. Coordination protocols can ensure consistency, but in practice they cause undesirable performance unless used judiciously. Scalable distributed architectures avoid coordination whenever possible, but ..."
Abstract
-
Cited by 12 (4 self)
- Add to MetaCart
(Show Context)
Abstract-Distributed consistency is perhaps the most discussed topic in distributed systems today. Coordination protocols can ensure consistency, but in practice they cause undesirable performance unless used judiciously. Scalable distributed architectures avoid coordination whenever possible, but undercoordinated systems can exhibit behavioral anomalies under fault, which are often extremely difficult to debug. This raises significant challenges for distributed system architects and developers. In this paper we present BLAZES, a cross-platform program analysis framework that (a) identifies program locations that require coordination to ensure consistent executions, and (b) automatically synthesizes application-specific coordination code that can significantly outperform general-purpose techniques. We present two case studies, one using annotated programs in the Twitter Storm system, and another using the Bloom declarative language.
Consistency Without Borders
"... Distributed consistency is a perennial research topic; in recent years it has become an urgent practical matter as well. The research literature has focused on enforcing various flavors of consistency at the I/O layer, such as linearizability of read/write registers. For practitioners, strong I/O co ..."
Abstract
-
Cited by 4 (1 self)
- Add to MetaCart
(Show Context)
Distributed consistency is a perennial research topic; in recent years it has become an urgent practical matter as well. The research literature has focused on enforcing various flavors of consistency at the I/O layer, such as linearizability of read/write registers. For practitioners, strong I/O consistency is often impractical at scale, while looser forms of I/O consistency are difficult to map to application-level concerns. Instead, it is common for developers to take matters of distributed consistency into their own hands, leading to application-specific solutions that are tricky to write, test and maintain. In this paper, we agitate for the technical community to shift its attention to approaches that lie between the extremes of I/O-level and application-level consistency. We ground our discussion in early work in the area, including our own experiences building programmer tools and languages that help developers guarantee distributed consistency at the application level. Much remains to be done, and we highlight some of the challenges that we feel deserve more attention. 1
On the CRON Conjecture
"... Abstract. Declarative networking is a recent approach to programming distributed applications with languages inspired by Datalog. A recent conjecture posits that the delivery of messages should respect causality if and only if they are used in non-monotone derivations. We present our results about t ..."
Abstract
-
Cited by 1 (1 self)
- Add to MetaCart
(Show Context)
Abstract. Declarative networking is a recent approach to programming distributed applications with languages inspired by Datalog. A recent conjecture posits that the delivery of messages should respect causality if and only if they are used in non-monotone derivations. We present our results about this conjecture in the context of Dedalus, a Datalogvariant for distributed programming. We show that both directions of the conjecture fail under a strong semantical interpretation. But on a more syntactical level, we can show that positive Dedalus programs can tolerate non-causal messages, in the sense that they compute the correct answer when messages can be sent into the past. 1
Positive Dedalus Programs Tolerate Non-Causality $
"... Abstract Declarative networking is a recent approach to programming distributed applications with languages inspired by Datalog. A recent conjecture posits that the delivery of messages should respect causality if and only if they are used in non-monotone derivations. We present our results about t ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract Declarative networking is a recent approach to programming distributed applications with languages inspired by Datalog. A recent conjecture posits that the delivery of messages should respect causality if and only if they are used in non-monotone derivations. We present our results about this conjecture in the context of Dedalus, a Datalog-variant for distributed programming. We show that both directions of the conjecture fail under a strong semantical interpretation. But on a more syntactical level, we show that positive Dedalus programs can tolerate non-causal messages, in the sense that they compute the correct answer even when messages can be sent into the past.
