electricshampo1

6 ms·

1.
by electricshampo1 1y ago
Depending on the IOPS rate for your app; SPDK can result in less CPU time spent in issuing IO/reaping completions compared to ex. io_uring. See Ex. https://www.vldb.org/pvldb/vol16/p2090-haas.pdf What Modern
2.
by electricshampo1 1y ago
From the pdf of the bill, software is still classified as R&D on page 303 of this bill; the change is that domestic (US) software R&D is no longer forced into a 5yr amortization schedule. Foreign software R&D is still forced to
3.
by electricshampo1 1y ago
Nice to see SDC concerns being taken more seriously by hardware folks. Once software gets to sufficient quality (which we have achieved in many cases), these kinds of rando hw issues are the only remaining causes of "impossible"
4.
Using high bandwidth PCIe 5 SSDs in databases(link.springer.com)
6 points by electricshampo1 2y ago|1 comments
5.
by electricshampo1 2y ago
The gap between the efficiency displayed here and that which can be found in ex. postgres/mysql is insane.
6.
by electricshampo1 2y ago
It is integer factors better overall total BW than ddr5 spr; I think they went for minimal investment + time to market for the spr w/ hbm product rather than heavy investment to hit full bw utilization. Which may have made sense for in
7.
by electricshampo1 2y ago
Completely agree re: firedancer codebase. There is a level of thought and discipline wrt performance that I have never seen anywhere else.
8.
Scalable Linearizable Caching(dropbox.tech)
1 points by electricshampo1 2y ago|0 comments
9.
by electricshampo1 2y ago
On prod servers I see a bunch of frontend stalls & code misses in the L2 for the kernel tcp stack; having each process statically embed its own network stack may make that worse (though using dynamic shared quic lib for ex. in userspace
10.
Chrono: Scalable Consistent Caching(dropbox.tech)
3 points by electricshampo1 2y ago|0 comments
11.
by electricshampo1 2y ago
Thanks for this link; did not realize that they did this.
12.
by electricshampo1 4y ago
Answering only the latter question: A Primer on Memory Consistency and Cache Coherence, Second Edition https://www.morganclaypool.com/doi/10.2200/S00962ED2V01Y2019... (free online book) would help
13.
Detection and Prevention of Silent Data Corruption in Spanner [pdf](storage.googleapis.com)
2 points by electricshampo1 4y ago|0 comments
14.
by electricshampo1 4y ago
" Like many modern analytical engines [18, 20], Procella does not use the conventional BTree style secondary indexes, opting instead for light weight secondary structures such as zone maps, bitmaps, bloom filters, partition and sort ke
15.
by electricshampo1 4y ago
The whole chip in general will be used in aggregate by independent vms/containers etc that do NOT read and write to the same memory. Some kernel datastructures within a given vm are still shared, ditto for within a single process, but
16.
by electricshampo1 4y ago
It might be helpful to read something like DB2 with BLU Acceleration: So Much More than Just a Column Store https://db.cs.pitt.edu/courses/cs3551/16-1/handouts/db2BLU.p... or Real-Time Analytical Process
17.
by electricshampo1 4y ago
Unlike goroutines, seems here you have control over the execution schedule for the virtual threads if you provide an executor. This is pretty great. Think this will obsolete go over the next few decades.
18.
by electricshampo1 4y ago
This is only on the client side; server still has and will have AVX512 for the foreseeable future.
19.
by electricshampo1 4y ago
"However, we were talking about array indexes, for loops, and file offsets for a single file. These are 8 byte variables within a running program." This depends on storage/page layout etc. See for ex. https://db.cs
20.
by electricshampo1 5y ago
Is Swift ( https://dl.acm.org/doi/pdf/10.1145/3387514.3406591 ) expected/designed to be used in non-intra dc environments where primarily quic is expected to have an advantage relative to tcp? I agree that
21.
by electricshampo1 5y ago
Generally for perf critical use cases you dedicate the machine to the database. This simplifies many things (avoiding having to reason about sharing, etc etc).
22.
by electricshampo1 5y ago
Seems like facebook's internal db TAO supports it according to https://www.vldb.org/pvldb/vol14/p3014-cheng.pdf
23.
by electricshampo1 5y ago
Seems 400M is aggregated qps worldwide. Wonder what avg qps looks like per iam server (and size of server).
24.
by electricshampo1 5y ago
This is just best effort on google's end right? Don't think anything is documented/guaranteed such that you would be able to, for ex. rely on it like spanner's use of true time.
25.
by electricshampo1 5y ago
Very often people are looking at icache misses instead of something more precise when regarding perf effects due to code size/layout, etc. That more precise thing is frontend stalls: you only care about misses when they cause stalls; o
26.
by electricshampo1 5y ago
"Java and JavaScript have avoided introducing weak (acquire/release) synchronizing atomics, which seem tailored for x86." This is not true for Java; see http://gee.cs.oswego.edu/dl/html/j9mm.html h
27.
by electricshampo1 5y ago
This is essentially the approach taken by https://www.dpdk.org/ (network) and https://spdk.io/ (storage) Anything trying to squeeze perf doing IO intensive work should switch to this model (context permitti
28.
by electricshampo1 5y ago
Thanks for the reference.
29.
by electricshampo1 5y ago
For this load shedding in a single node, are you imagining something more than work stealing style approaches? In a multi-node cooperative setting you need some way to transmit information that a given node is overloaded, some way to find n
30.
by electricshampo1 6y ago
I don't know about latest; but try look at Scheduling Parallel Programs by Work Stealing with Private Deques https://hal.inria.fr/file/index/docid/863028/filename/full.p...

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