RE: RBD thoughts

2014-05-07 Thread Allen Samuels
implementation task. --- Never put off until tomorrow what you can do the day after tomorrow. Mark Twain Allen Samuels Chief Software Architect, Emerging Storage Solutions 951 SanDisk Drive, Milpitas, CA 95035 T: +1 408 801 7030| M: +1 408 780 6416

RE: RBD thoughts

2014-05-07 Thread Allen Samuels
. --- Now I know what a statesman is; he's a dead politician. We need more statesmen. Bob Edwards Allen Samuels Chief Software Architect, Emerging Storage Solutions 951 SanDisk Drive, Milpitas, CA 95035 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original

RE: [Feature]Proposal for adding a new flag named shared to support performance and statistic purpose

2014-06-05 Thread Allen Samuels
You talk about restting the object map on a restart after a crash -- I assume you mean rebuilding, how long will this take? --- The true mystery of the world is the visible, not the invisible. Oscar Wilde (1854 - 1900) Allen Samuels

RE: Regarding key/value interface

2014-09-12 Thread Allen Samuels
Another thing we're looking into is compression. The intersection of compression and object striping (fracturing) is interesting. Is the striping variable on a per-object basis? Allen Samuels Chief Software Architect, Emerging Storage Solutions 951 SanDisk Drive, Milpitas, CA 95035 T: +1 408

RE: Inline dedup/compression

2015-07-02 Thread Allen Samuels
objects are replicated rather than ECed). This will have a massive impact on backend storage I/O as the basic data/metadata ratio is complete skewed (both for static storage and dynamic I/O count). Allen Samuels Software Architect, Emerging Storage Solutions 2880 Junction Avenue, Milpitas, CA

RE: Ceph Hackathon: More Memory Allocator Testing

2015-08-19 Thread Allen Samuels
memory discussion will go away. Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message- From: ceph-devel-ow...@vger.kernel.org [mailto:ceph-devel-ow

RE: Inline dedup/compression

2015-08-20 Thread Allen Samuels
I was referring strictly to compression. Dedupe is a whole 'nother issue. I agree that dedupe on a per-OSD basis isn't interesting. It needs to be done at the pool level (or higher). Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T

RE: Inline dedup/compression

2015-08-20 Thread Allen Samuels
diversity. Then you'd want to add verbiage to the individual access schemes to allow/disallow compression. For file systems you'd want that on a per-directory basis or perhaps even better a set of regular expressions. Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction

RE: Inline dedup/compression

2015-06-30 Thread Allen Samuels
This covers the read and write, what about the delete? One of the major issues with Dedupe, whether global or local is to address the inherent ref-counting associated with sharing of pieces of storage. Allen Samuels Software Architect, Emerging Storage Solutions 2880 Junction Avenue, Milpitas

RE: The design of the eviction improvement

2015-07-22 Thread Allen Samuels
to storage with some mechanism that allows batched updates. Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message- From: ceph-devel-ow...@vger.kernel.org

RE: The design of the eviction improvement

2015-07-22 Thread Allen Samuels
Don't we need to double-index the data structure? We need it indexed by atime for the purposes of eviction, but we need it indexed by object name for the purposes of updating the list upon a usage. Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction Avenue, San

RE: The design of the eviction improvement

2015-07-22 Thread Allen Samuels
high counts of small objects. I agree that paying $ for RAM that translates into actual performance isn't really a problem. It really boils down to your workload and access pattern. Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1

RE: The design of the eviction improvement

2015-07-20 Thread Allen Samuels
This seems much better than the current mechanism. Do you have an estimate of the memory consumption of the two lists? (In terms of bytes/object?) Allen Samuels Software Architect, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416

RE: newstore direction

2015-10-22 Thread Allen Samuels
How would this kind of split affect small transactions? Will each split be separately transactionally consistent or is there some kind of meta-transaction that synchronizes each of the splits? Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San

RE: newstore direction

2015-10-21 Thread Allen Samuels
I am pushing internally to open-source ZetaScale. Recent events may or may not affect that trajectory -- stay tuned. Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu

RE: newstore direction

2015-10-21 Thread Allen Samuels
-per-core software development will also tend to support the "do it in user-space" trend. That's because most of the kernel and file-system interface is architected around the blocking "thread-per-IOP" model and is unlikely to change in the future. Allen Samuels Software Archi

RE: newstore direction

2015-10-21 Thread Allen Samuels
roadblock. Just my experience. YMMV. Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message- From: Ric Wheeler [mailto:rwhee...@redhat.

RE: newstore direction

2015-10-21 Thread Allen Samuels
of DRAM. Regardless of the choice, you'll see a significant degradation of performance while the scrub is ongoing -- which is one of the biggest problems with clustered systems (expensive and extensive maintenance operations). Allen Samuels Software Architect, Fellow, Systems and Software

RE: newstore direction

2015-10-21 Thread Allen Samuels
that into the equation the "on top of an FS" path doesn't look like such a clear winner. Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message-

RE: Notes from a discussion a design to allow EC overwrites

2015-11-13 Thread Allen Samuels
to a subsequent release (i.e., I'm out of large blocks, but there's plenty of fragmented available space -- This can happen, but's a pretty pathological case which becomes rare-er and rare-er as you scale-out) Allen Samuels Software Architect, Emerging Storage Solutions 2880 Junction Avenue

RE: Question about how rebuild works.

2015-11-06 Thread Allen Samuels
rebuild. The average case would be 1.5x and this is inverse with the MTTDL, i.e., this behavior cuts the MTTDL in half. Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu

RE: newstore direction

2015-10-21 Thread Allen Samuels
you're using a file system. Yes an LSM tree performs better on HDD than does a B-tree, which is a good argument for keeping the KV module pluggable. Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408

RE: newstore direction

2015-10-21 Thread Allen Samuels
required for deep scrubbing. Allen Samuels Software Architect, Fellow, Systems and Software Solutions 2880 Junction Avenue, San Jose, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message- From: ceph-devel-ow...@vger.kernel.org [mailto:ceph-devel-ow

RE: loadable objectstore

2015-09-12 Thread Allen Samuels
which is loaded from a known constant offset in the object). Allen Samuels Chief Software Architect, Emerging Storage Solutions 951 SanDisk Drive, Milpitas, CA 95035 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message- From: ceph-devel-ow

RE: loadable objectstore

2015-09-14 Thread Allen Samuels
Yes, I'm referring to the C++ vtable. Allen Samuels Software Architect, Emerging Storage Solutions 2880 Junction Avenue, Milpitas, CA 95134 T: +1 408 801 7030| M: +1 408 780 6416 allen.samu...@sandisk.com -Original Message- From: James (Fei) Liu-SSI [mailto:james@ssi.samsung.com