Abstract: The disclosed subject matter provides techniques for detecting and diagnosing mobile app bugs. An approximate execution mode screens for potential bugs, which can expose bugs but can generate false positives. From the generated bug reports, certain bugs can be automatically validated and false positives pruned, reducing the need for manual inspection.

Abstract: A data partitioning plan is automatically generated that—given a data-parallel program and a large input dataset, and without having to first run the program on the input dataset—substantially optimizes performance of the distributed execution system that explicitly measures and infers various properties of both data and computation to perform cost estimation and optimization. Estimation may comprise inferring the cost of a candidate data partitioning plan, and optimization may comprise generating an optimal partitioning plan based on the estimated costs of computation and input/output.

Abstract: Methods, systems, and media for providing determinism in multithreaded programs are provided. In some embodiments, methods for providing determinism in multithreaded programs are provided, the methods comprising: instrumenting a program with: a proxy that: receives inputs to the program; and determines whether a schedule corresponding to a set of input constraints satisfied by the inputs has been memoized; and a replayer that: if it is determined that a schedule corresponding to a set of input constraints satisfied by the inputs has been memoized, processes the inputs by the program according to the schedule.

Abstract: Methods, systems, and media for protecting applications from races are provided. In some embodiments, methods for protecting applications from races are provided, the methods comprising: adding to at least one cycle of the application an update check to determine when an update to the application is to be made; adding an update engine to the application, wherein the update engine is configured to: receive an update plan that is based on an execution filter that specifies how operations of the application are to be synchronized; and cause synchronization operations to be added to the application based on the update plan that prevent the race from occurring.

Abstract: A technique for automatically detecting and correcting configuration errors in a computing system. In a learning process, recurring event sequences, including e.g., registry access events, are identified from event logs, and corresponding rules are developed. In a detecting phase, the rules are applied to detected event sequences to identify violations and to recover from failures. Event sequences across multiple hosts can be analyzed. The recurring event sequences are identified efficiently by flattening a hierarchical sequence of the events such as is obtained from the Sequitur algorithm. A trie is generated from the recurring event sequences and edges of nodes of the trie are marked as rule edges or non-rule edges. A rule is formed from a set of nodes connected by rule edges. The rules can be updated as additional event sequences are analyzed. False positive suppression policies include a violation-consistency policy and an expected event disappearance policy.

Abstract: A distributed system checker may check a distributed system against events to detect bugs in the distributed system. The events may include machines crashes, network partitions, and packet losses, for example. The distributed system checker may check a distributed system that can have multiple threads and multiple processes running on multiple nodes. To obtain control over a distributed system, a distributed system checker may insert an interposition layer between a process and the operating system on each node.

Abstract: A technique for automatically detecting and correcting configuration errors in a computing system. In a learning process, recurring event sequences, including e.g., registry access events, are identified from event logs, and corresponding rules are developed. In a detecting phase, the rules are applied to detected event sequences to identify violations and to recover from failures. Event sequences across multiple hosts can be analyzed. The recurring event sequences are identified efficiently by flattening a hierarchical sequence of the events such as is obtained from the Sequitur algorithm. A trie is generated from the recurring event sequences and edges of nodes of the trie are marked as rule edges or non-rule edges. A rule is formed from a set of nodes connected by rule edges. The rules can be updated as additional event sequences are analyzed. False positive suppression policies include a violation- consistency policy and an expected event disappearance policy.

Abstract: A distributed system checker may check a distributed system against events to detect bugs in the distributed system. The events may include machines crashes, network partitions, and packet losses, for example. The distributed system checker may check a distributed system that can have multiple threads and multiple processes running on multiple nodes. To obtain control over a distributed system, a distributed system checker may insert an interposition layer between a process and the operating system on each node.

Abstract: A distributed data store employs replica placement techniques in which a number k hash functions are used to compute k potential locations for a data item. A number r of the k locations are chosen for storing replicas. These replica placement techniques provide a system designer with the freedom to choose r from k, are structured in that they are determined by a straightforward functional form, and are diffuse such that the replicas of the items on one server are scattered over many other servers. The resulting storage system exhibits excellent storage balance and request load balance in the presence of incremental system expansions, server failures, and load changes. Data items may be created, read, and updated or otherwise modified.