Project Design Principles

The following principles drive design decisions in the project.


The library and tools should be designed such that running with more processes increases performance, provided there are sufficient data and parallelism available in the underlying file systems. The design of the tool should not impose performance scalability bottlenecks.


While it is tempting to mimic the interface, behavior, and file formats of familiar tools like cp, rm, and tar, when forced with a choice between compatibility and performance, mpiFileUtils chooses performance. For example, if an archive file format requires serialization that inhibits parallel performance, mpiFileUtils will opt to define a new file format that enables parallelism rather than being constrained to existing formats. Similarly, options in the tool command line interface may have different semantics from familiar tools in cases where performance is improved. Thus, one should be careful to learn the options of each tool.


The tools are intended to support common file systems used in HPC centers, like Lustre, GPFS, and NFS. Additionally, methods in the library should be portable and efficient across multiple file systems. Tool and library users can rely on mpiFileUtils to provide portable and performant implementations.


While the tools do not support chaining with Unix pipes, they do support interoperability through input and output files. One tool may process a dataset and generate an output file that another tool can read as input, e.g., to walk a directory tree with one tool, filter the list of file names with another, and perhaps delete a subset of matching files with a third. Additionally, when logic is deemed to be useful across multiple tools or is anticipated to be useful in future tools or applications, it should be provided in the common library.