ASDF: An Autonomous and Scalable Distributed File System . many of the same goals as previous distributed file systems such as scalability. Distributed File System (DFS) could be a set of consumer and server .. Huang and Huan-Ming Liang, “ASDF: An Autonomous and Scalable Distributed. File. 3 / Abstract. We have simulated SimpleFS, a simple and scalable distributed file system for nowadays highly Other file systems, like TidyFS, ASDF, Ceph, etc, utilize similar concepts but take more .. ASDF: An Autonomous and. Scalable.

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New features also include: Running Lisp code to portably create executable commands from Lisp is great, but there is a bootstrapping problem: What is worse, changing syntax is only useful if it also happens at the interactive REPL and in appropriate editor buffers. The principle of visiting the action graph multiple times is generalizable scalabke other situations, and the maximum number scalabpe visits of a given node is the height of the semi-lattice of node states during the traversal.

1 Ceph Distributed Storage Sage Weil DreamHost / new dream network April 7, 2011.

Also lib-op links into a library all the object files in a system and dll-op creates a dynamically loadable library out of them. Happily, each implementation provides its own extensions and there exist libraries to abstract over the discrepancies between these implementations and provide portable access to threads bordeaux-threadsUnicode support cl-unicodea “foreign function interface” scalble libraries written in C cffiML-style pattern-matching optimaetc.

A recurrent question to ASDF developers was about how to properly modify the CL syntax for some files, without breaking the syntax for other files: Autonoomus discussing pathnames in Appendix C: A negative infinity marker implemented as boolean nil also serves to mark as no dependency.


You could try to provide an explicit pathname option to your component definition as in: Logical pathnames thus intrinsically do not scale. UIOP implements predicates file-pathname-p and directory-pathname-p to distinguish between the two kinds of pathnames and there are yet more kinds of pathname objects, because of wildcards. Changing the semantics of one software system while other systems keep relying on it is akin to changing the wheels on a running car: Scalaable code had a lot of rough edges: What then, is backward compatibility?

The greatest source of portability woes was in handling pathnames: This bilingual program, both a portable shell script and a portable CL program, provides a nice colloquial shell command interface to building shell commands from Lisp code, and supports delivery as either portable systm scripts or self-contained precompiled executable files.

There were many cases during ASDF development where we wanted to rename a function or change the behavior of a class. POIU compiles files in parallel on Unix multiprocessors using forkwhile still loading them sequentially into a main image, minimizing latency.

Chronologically, however, we consciously started this porting process in interaction with developing ASDF 3, thus ensuring ASDF 3 had all the extension hooks required to avoid redefinitions. The DAG defines a partial order, whereby each action must be perform ed, but only after all the actions it transitively depends-on have already been performed.

But in other important ways ASDF demonstrates how these C systems have much accidental complexity that CL does away with thanks to better architecture. To avoid subtle mistakes, the latter are conventionally named with enclosing asterisks, also known in recent years as earmuffs. Share buttons are a little bit lower. To tell ASDF 3. The fike were found in while working on ASDF 2; they were partially fixed, but support for the selective syntax was guarded by a continuable error message inviting users to contact the maintainer.


Each implementation shipped its own old version, often slightly edited; system definition semantics often varied subtly between implementations, notably regarding pathnames.

ASDF 3 gets rid of: Only then, could the same specification be used on all supported platforms with the same semantics.

学术圈 – Reclaiming Space from Duplicate Files in a Serverless Distributed File System

Failed Attempts at Improvement. A glaring issue, for instance, ahd causing much aggravation in large projects: Failed Attempts at Improvement ; and the bug that required rewriting it all over again in Appendix F: The principle followed was that the cognitive load on each kind of user must be minimized. Most of the utilities deal with providing sane pathname abstractions see Appendix C: O log n calculation Stable: A type, if provided by the component or its class and not nilis always added at the end of the provided name.

More Cooperation, Less Coordination.

ASDF did scale reasonably well to a large number of small systems, because it was using a hash-table to find systems; on the other hand, there was a dependency propagation bug in this case see Appendix F: