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Modern applications use storage systems in complex and often surprising ways. Tracing system calls is a common approach to understanding applications' behavior, allowing offline analysis and enabling replay in other environments. But current system-call tracing tools have drawbacks: (1) they often omit some information---such as raw data buffers---needed for full analysis; (2) they have high overheads; (3) they often use non-portable trace formats; and (4) they may not offer useful and scalable analysis and replay tools. We have developed Re-Animator, a powerful system-call tracing tool that focuses on storage-related calls and collects maximal information, capturing complete data buffers and writing all traces in the standard DataSeries format. We also created a prototype replayer that focuses on calls related to file-system state. We evaluated our system on long-running server applications such as key-value stores and databases. Our tracer has an average overhead of only 1.8-2.3×, but the overhead can be as low as 5% for I/O-bound applications. Our replayer verifies that its actions are correct, and faithfully reproduces the logical file system state generated by the original application.
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Recorder 2.0: Efficient Parallel I/O Tracing and Analysis
Recorder is a multi-level I/O tracing tool that captures HDF5, MPI-I/O, and POSIX I/O calls. In this paper, we present a new version of Recorder that adds support for most metadata POSIX calls such as stat, link, and rename. We also introduce a compressed tracing format to reduce trace file size and run time overhead incurred from collecting the trace data. Moreover, we add a set of post-mortem and visualization routines to our new version of Recorder that manage the compressed trace data for users. Our experiments with four HPC applications show a file size reduction of over 2× and reduced post-processing time by 20% when using our new compressed trace file format.
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- Award ID(s):
- 1763540
- PAR ID:
- 10155948
- Date Published:
- Journal Name:
- The IEEE International Workshop on High-Performance Storage
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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