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unum-cloud
UStore
C++2022–2023
unum-cloud / UStore

UStore

Embedded transactional database for blobs, documents & graphs, with kernel-bypass NVMe through io_uring & SPDK, GPU compaction, and one C ABI over its own, RocksDB & LevelDB engines 🗄️

3Distinct people
8Mentions
0Explicit recommenders
649GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Embedded transactional database for blobs, documents & graphs, with kernel-bypass NVMe through io_uring & SPDK, GPU compaction, and one C ABI over its own, RocksDB & LevelDB engines 🗄️

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by month8 dated mentions

Observed mentions: 2022-12-27 15:02:39 UTC to 2023-10-16 11:19:06 UTC.

01232022-12-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 1 mentions; 1 submissions, 0 commentsDec 20222023-01-01 00:00:00 UTC to 2023-02-01 00:00:00 UTC (exclusive): 3 mentions; 1 submissions, 2 comments2023-02-01 00:00:00 UTC to 2023-03-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2023-03-01 00:00:00 UTC to 2023-04-01 00:00:00 UTC (exclusive): 2 mentions; 1 submissions, 1 comments2023-04-01 00:00:00 UTC to 2023-05-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2023-05-01 00:00:00 UTC to 2023-06-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 commentsMay 20232023-06-01 00:00:00 UTC to 2023-07-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2023-07-01 00:00:00 UTC to 2023-08-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2023-08-01 00:00:00 UTC to 2023-09-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2023-09-01 00:00:00 UTC to 2023-10-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2023-10-01 00:00:00 UTC to 2023-11-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 commentsOct 2023

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
Dec 20222022-12-01 00:00:00 UTC2023-01-01 00:00:00 UTC110
Jan 20232023-01-01 00:00:00 UTC2023-02-01 00:00:00 UTC312
Feb 20232023-02-01 00:00:00 UTC2023-03-01 00:00:00 UTC101
Mar 20232023-03-01 00:00:00 UTC2023-04-01 00:00:00 UTC211
Apr 20232023-04-01 00:00:00 UTC2023-05-01 00:00:00 UTC000
May 20232023-05-01 00:00:00 UTC2023-06-01 00:00:00 UTC000
Jun 20232023-06-01 00:00:00 UTC2023-07-01 00:00:00 UTC000
Jul 20232023-07-01 00:00:00 UTC2023-08-01 00:00:00 UTC000
Aug 20232023-08-01 00:00:00 UTC2023-09-01 00:00:00 UTC000
Sep 20232023-09-01 00:00:00 UTC2023-10-01 00:00:00 UTC000
Oct 20232023-10-01 00:00:00 UTC2023-11-01 00:00:00 UTC101

What Hacker News says

8 sources
I don't remember exactly why I have any of them saved, but these are some experimental data stores that seems to be fitting what you're looking for somewhat: - https://github.com/DataManagementLab/ScaleStore - "A Fast and Cost-Efficient Storage Engine using DRAM, NVMe, and RDMA" - https://github.com/unum-cloud/udisk (https://github.com/unum-cloud/ustore) - "The fastest ACID-transactional persisted Key-Value store designed for NVMe block-devices with GPU-acceleration and SPDK to bypass the Linux kernel." - https://github.com/capsuleman/ssd-nvme-database - "Columnar database on SSD NVMe"
In Ask HN: Why are there no open source NVMe-native key value stores in 2023?
Yes, we also constantly think about that! In the document collections of UKV, for example, we have interoperability between JSON, BSON, and MessagePack objects [1]. CSV is another potential option, but text-based formats aren't ideal for large scale transmissions. One thing people do - use two protocols. That is the case with Apache Arrow Flight RPC = gRPC for tasks, Arrow for data. It is a viable path, but compiling gRPC is a nightmare, and we don't want to integrate it into our other libraries, as we generally compile everything from sources. Seemingly, UJRPC can replace gRPC, and for the payload we can continue using Arrow. We will see :) [1]: https://github.com/unum-cloud/ukv/blob/main/src/modality_doc...
In Show HN: Faster FastAPI with simdjson and io_uring on Linux 5.19

Show HN: Faster FastAPI with simdjson and io_uring on Linux 5.19

A few months ago, I benchmarked FastAPI on an i9 MacBook Pro. I couldn't believe my eyes. A primary REST endpoint to `sum` two integers took 6 milliseconds to evaluate. It is okay if you are targeting a server in another city, but it should be less when your client and server apps are running on the same machine. FastAPI would have bottleneck-ed the inference of our lightweight UForm neural networks recently trending on HN under the title "Beating OpenAI CLIP with 100x less data and compute". (Thank you all for the kind words!) So I wrote another library. It has been a while since I have written networking libraries, so I was eager to try the newer io_uring networking functionality added by Jens Axboe in kernel 5.19. TLDR: It's excellent! We used pre-registered buffers and re-allocated file descriptors from a managed pool. Some other part
Read the rest
s, like multi-shot requests, also look intriguing, but we couldn't see a flawless way to integrate them into UJRPC. Maybe next time. Like a parent with two kids, we tell everyone we love Kernel Bypass and SIMD equally. So I decided to combine the two, potentially implementing one of the fastest implementations of the most straightforward RPC protocol - JSON-RPC. ~~Healthy and Fun~~ Efficient and Simple, what can be better? By now, you may already guess at least one of the dependencies - `simdjson` by Daniel Lemiere, that has become the industry standard. io_uring is generally very fast, even with a single core. Adding more polling threads may only increase congestion. We needed to continue using no more than one thread, but parsing messages may involve more work than just invoking a JSON parser. JSON-RPC is transport agnostic. The incoming requests can be sent over HTTP, pre-pended by rows of headers. Those would have to be POSTs and generally contain Content-Length and Content-Type. There is a SIMD-accelerated library for that as well. It is called `picohttpparser`, uses SSE, and is maintained by H2O. The story doesn't end there. JSON is limited. Passing binary strings is a nightmare. The most common approach is to encode them with base-64. So we took the Turbo-Base64 from the PowTurbo project to decode those binary strings. The core implementation of UJRPC is under 2000 lines of C++. Knowing that those lines connect 3 great libraries with the newest and coolest parts of Linux is enough to put a smile on my face. Most people are more rational, so here is another reason to be cheerful. - FastAPI throughput: 3'184 rps. - Python gRPC throughput: 9'849 rps. - UJRPC throughput: -- Python server with io_uring: 43'000 rps. -- C server with POSIX: 79'000 rps. -- C server with io_uring: 231'000 rps. Granted, this is yet to be your batteries-included server. It can't balance the load, manage threads, spell S in HTTPS, or call parents when you misbehave in school. But at least part of it you shouldn't expect from a web server. After following the standardization process of executors in C++ for the last N+1 years, we adapted the "bring your runtime" and "bring your thread-pool" policies. HTTPS support, however, is our next primary objective. --- Of course, it is a pre-production project and must have a lot of bugs. Don't hesitate to report them. We have huge plans for this tiny package and will potentially make it the default transport of UKV: https://github.com/unum-cloud/ukv
290 points · Open discussion
Great point! I would be happy to get more input and brain-storm a good pricing model together, one that is fair both for developers and for users. We have an source project UKV, that partly overlaps with vector-search: https://github.com/unum-cloud/ukv Another one - UNSW, is a placeholder for now: https://github.com/unum-cloud/unsw Both will be soon available on cloud marketplaces, but server-less options are a bit harder to cook. Our Discord is the best place to continue conversation: https://discord.gg/Bbh2bjNhvz Thank you for advice!
In Beating OpenAI CLIP with 100x less data and compute
I am really stunned by this story. It made me check the MemGraph benchmarks section. Don't get me wrong, it may be 10-100x faster than Neo4J in even the most basic operations. Moreover, given the quality of Neo4J, it is hard not to be that much quicker. Even Postgres and MySQL are better at storing graphs than Neo4J. --- Disclosure: I have worked on Graph Algorithms, Graph Databases, and Database Engines for years, and we are now preparing a commercial solution based on UKV [1]. I don't know anyone at MemGraph or Neo4J. Never used the first. As for the second, I am not a fan. --- Aside from licensing, there are 3 primary complaints. I will address them individually, and I am open to a discussion. A. Using Python for Benchmarks instead of Gatling. I don't entirely agree with this. Python still has the fastest-growing programming community
Read the rest
while already being one of the 2 most popular languages. Gatling, however, never heard of it. Choosing between the two, I would pick Python. But neither works if you want to design a High-Performance benchmark for a fast system. Without automatic memory management and expensive runtimes, you can only implement those in C, C++, Rust, or another systems-programming language. We have faced that too many times that the benchmark itself works worse than the system it is trying to evaluate [2]. B. Using hardware from 2010 [3], weird datasets [4]. This shocked me. When I looked at the charts [5] and the benchmarking section, it seemed highly professional and good-looking. I wouldn't expect less from a startup with $20M VC funding. But the devil is in the details. I would have never expected anyone benchmarking a new DBMS to use now 13-year-old CPUs and an unknown dataset. Assuming current developer salaries, hiring people to design a DBMS doesn't make sense if you will be evaluating on a $1000 machine is just financially irresponsible. We buy expensive servers, they cost like sports cars or even apartments in poorer countries. It is hard to maintain, but they are essential to quality work. It is sad to see companies taking such shortcuts. But to be a devil's advocate, there is no 1 graph benchmark or dataset that everyone agrees on. So I imagine people experimenting with multiple real datasets of different sizes or generating them systemically using one of the Random Generator algorithms. In UKV, we have used Twitter data to construct both document and graph collections. In the past, we have also used `ci-patent`, `bio-mouse-gene`, `human-Jung2015-M87102575`, and hundreds of other public datasets from the Network Repository and SNAP [6]. There are datasets of every shape and size, reaching around 1 Billion edges, in case someone is searching for data. For us the next step is the reconstruction of the Web from the 300 TB CommonCrawl dataset [7]. There is no such Graph benchmark in existence, but it is the biggest public dataset we could find. C. Running query different number of times for various engines. This can be justified, and it is how current benchmarks are done. You are tracking not just the mean execution time but also variability, so if at some point results converge, you abrupt before hitting the expected iterations number to save time. --- LDBC [8] seems like a good contestant for a potential industry standard, but it needs to be completed. Its "Business Intelligence workload" and "Interactive workload" categories exclude any real "Graph Analytics". Running an All-Pairs-Shortest-Paths algorithm on a large external memory graph could have been a much more interesting integrated benchmark. Similarly, one can make large-scale community detection or personalized recommendations based on Graphs and evaluate the overall cost/performance. It, however, poses another big challenge. Almost all algorithm implementations for those problems are vertex-centric. They scale poorly with large sparse graphs that demand edge-centric algorithms, so a new implementation has to be written from scratch. We will try to allocate more resources towards that in 2023 and invite anyone curious to join. --- [1] https://github.com/unum-cloud/ukv [2] https://unum.cloud/post/2022-03-22-ucsb [3] https://github.com/memgraph/memgraph/tree/master/tests/mgben... [4] https://github.com/memgraph/memgraph/tree/master/tests/mgben... [5] https://memgraph.com/benchgraph/base [6] https://snap.stanford.edu/data [7] https://commoncrawl.org [8] https://ldbcouncil.org/benchmarks/snb
In Bullshit graph database performance benchmarks

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