DiceDB

https://dicedb.io/

by rainhacker • 1 year ago

235 131 1 year ago

dicedb.io

bdcravens3• 1 year ago

Is there a single sentence anywhere that describes what it actually is?

rvnx• 1 year ago

A Redis-inspired server in Go

adhamsalama• 1 year ago

Can't wait to feel the impact of garbage collection in my fast cache!

arpitbbhayani12• 1 year ago

Nope. it started as Redis clone. We are on a different trajectory now. Chasing different goals.

ekianjo• 1 year ago

seems like a key store, with an ability to watch/subscribe to monitor for the change of values in real time

arpitbbhayani12• 1 year ago

Yes. With DiceDB clients can "WATCH" the output of the commands and upon the change in data, the resultset are streamed to the subscribers.

mrbluecoat• 1 year ago

"A key store, with an ability to watch/subscribe to monitor for the change of values in real time."

Should be the first sentence on their website and repo.

bdcravens3• 1 year ago

Even clicking through to the Github, after reading the "What is DiceDB?", I'm still not very clear. It feels more like marketing than information.

"What is DiceDB? DiceDB is an open-source, fast, reactive, in-memory database optimized for modern hardware. Commonly used as a cache, it offers a familiar interface while enabling real-time data updates through query subscriptions. It delivers higher throughput and lower median latencies, making it ideal for modern workloads."

siddharthgoel88• 1 year ago

Drop in replacement of Redis.

arpitbbhayani12• 1 year ago

Nope. We are not redis compliant.

DrammBA2• 1 year ago

I've seen this more and more with software landing pages, they are somehow so deep into developing/marketing that they totally forget to say what the thing actually is or does, that's why you show it to family and friends first to get some fresh eyes before publishing the site.

lucianbr2• 1 year ago

In a similar vein, lots of software is Mac-only, but omits to say this anywehere. You just get to the downloads page and see that there are only mac packages.

As if nobody ever uses anything else.

lucianbr2• 1 year ago

No. I had the exact same problem.

Feels arrogant. "Of course you already know what this is, how could you not?"

goodpoint• 1 year ago

The video is also advertisement rather than a real thing.

johnisgood2• 1 year ago

Looks like a Redis clone. The benchmarks compare it to Redis.

Description from GitHub:

DiceDB is an open-source, fast, reactive, in-memory database optimized for modern hardware. Commonly used as a cache, it offers a familiar interface while enabling real-time data updates through query subscriptions. It delivers higher throughput and lower median latencies, making it ideal for modern workloads.

pcthrowaway2• 1 year ago

Not 100% a Redis clone, but the API appears to be very similar to Redis of 10 years ago, with some additions that Redis doesn't have. See the list of commands: https://dicedb.io/get-started/installation/

jlengrand• 1 year ago

I picked that up purely because of the logo / website palette / name choice combinations. Interestingly, not sure it's a good thing.

arpitbbhayani12• 1 year ago

Arpit here.

DiceDB is an in-memory database that is also reactive. So, instead of polling the database for changes, the database pushes the resultset if you subscribe to it.

We have a similar set of commands as Redis, but are not Redis-compliant.

remram4• 1 year ago

This is a lot clearer than any information I found anywhere else. There wasn't any room on your website, README, or docs for this summary?

ofrzeta2• 1 year ago

So like RethinkDB? https://rethinkdb.com/

nebulous16• 1 year ago

Would "key-value" not have a place in the description?

This application may be very capable, but I agree with the person saying that its use-case isn't clear on the home page, you have to go deeper into the docs. "Smarter than a database" also seems kind of debatable.

aloknnikhil• 1 year ago

In the list of things that DiceDB is at the top, you should add "an in-memory database". Pretty critical thing to leave out right at the top.

Apofis• 1 year ago

Question, how does DiceDB differ from Redis pub/sub? https://redis.io/docs/latest/develop/interact/pubsub/

remram4• 1 year ago

The docs do, the site is useless.

DiceDB is an open-source, fast, reactive, in-memory database optimized for modern hardware.

A Redis-like database with a Redis-like interface. No info about drop-in compatibility, I assume no.

spiderfarmer3• 1 year ago

DiceDB is an in-memory, multi-threaded key-value DBMS that supports the Redis protocol.

It’s written in Go.

arpitbbhayani12• 1 year ago

nope. We do not support Redis protocol :)

spiderfarmer3• 1 year ago

Did you remove support? Cause Google found mentions of it on your website.

datadeft• 1 year ago

Is this suffering from the same problems like Redis when trying to horizontally scale?

weekendcode2• 1 year ago

I guess yes.

DrammBA2• 1 year ago

I love the "Follow on twitter" link with the old logo and everything, they probably used a template that hasn't been updated recently but I'm choosing to believe it's actually a subtle sign of protest or resistance.

arpitbbhayani12• 1 year ago

I prefer that over X icon.

spiderfarmer3• 1 year ago

Just use Bluesky. It’s the better middle finger.

remram4• 1 year ago

This seems orders of magnitude slower than Nubmq which was posted yesterday: https://news.ycombinator.com/item?id=43371097

arpitbbhayani12• 1 year ago

Different tool. I metrics I am optimizing for are different hence wrote a separate utility. May not be the most optimized one. But I am usign this to measure all things DiceDB and will be using this to optimize DiceDB further.

ref: https://github.com/DiceDB/membench

alexey-salmin2• 1 year ago

  | Metric               | DiceDB   | Redis    |
  | -------------------- | -------- | -------- |
  | Throughput (ops/sec) | 15655    | 12267    |
  | GET p50 (ms)         | 0.227327 | 0.270335 |
  | GET p90 (ms)         | 0.337919 | 0.329727 |
  | SET p50 (ms)         | 0.230399 | 0.272383 |
  | SET p90 (ms)         | 0.339967 | 0.331775 |

UPD Nevermind, I didn't have my eyes open. Sorry for the confusion.

Something I still fail to understand is where you can actually spend 20ms while answering a GET request in a RAM keyvalue storage (unless you implement it in Java).

I never gained much experience with existing opensource implementations, but when I was building proprietary solutions at my previous workplace, the in-memory response time was measured in tens-hundreds of microseconds. The lower bound of latency is mostly defined by syscalls so using io_uring should in theory result in even better timings, even though I never got to try it in production.

If you read from nvme AND also do the erasure-recovery across 6 nodes (lrc-12-2-2) then yes, you got into tens of milliseconds. But seeing these numbers for a single node RAM DB just doesn't make sense and I'm surprised everyone treats them as normal.

Does anyone has experience with low-latency high-throughput opensource keyvalue storages? Any specific implementation to recommend?

davekeck• 1 year ago

Something I still fail to understand is where you can actually spend 20ms

Aren’t these numbers .2 ms, ie 200 microseconds?

Kerbonut• 1 year ago

Looks like your units are in ms, so 0.20 ms.

alexey-salmin2• 1 year ago

oh thank you, it's just me being blind

esafak• 1 year ago

They also sounded fishy to me. I'd expect closer to 10x as much throughput with Redis: https://redis.io/docs/latest/operate/oss_and_stack/managemen...

bitlad2• 1 year ago

I think it is fishy based on this - https://dzone.com/articles/performance-and-scalability-analy...

ajnin• 1 year ago

I had the same reaction as you. And that's for 4 simultaneous clients, too, for a single client you get 3159 ops/s (from https://dicedb.io/benchmarks/). I'm not too familiar with in-memory databases in general but I would have expected figures in the millions on modern hardware. Makes me feel there's some hidden bottleneck somewhere and the benchmarks are not purely measuring the performance of the software.

ac130kz3• 1 year ago

Any reason to use this over Valkey, which is now faster than Redis and community driven? Genuinely interested.

hp773• 1 year ago

DragonflyDB is also in that race, isn't it?

ac130kz3• 1 year ago

From what I looked at in the past, they seem better on paper by comparing themselves to a very old version of Redis in a rigged scenario (no clustering or multithreading applied despite Drangonfly getting multithreading enabled), and they are a lot worse in terms of code updates. Maybe that's different today, but I'm more keen on using Valkey.

OutOfHere• 1 year ago

In-memory caches (lacking persistence) shouldn't be called a database. It's not totally incorrect, but it's an abuse of terminology. Why is a Python dictionary not an in-memory key-value database?

rebolek• 1 year ago

- proudly open source. cool! - join discord. YAY :(

schmookeeg• 1 year ago

Using an instrument of chance to name a data store technology is pretty amusing to me.

bufferoverflow• 1 year ago

No chance if we live in a deterministic universe.

dkh4• 1 year ago

This is essentially what all in-memory data stores have always been

Kinda refreshing to see someone own it and run with it

sidcool• 1 year ago

Is Arpit is the system design course guy?

arpitbbhayani12• 1 year ago

Yes. I do run a sys design course on weekends.

bitlad2• 1 year ago

I think performance benchmark you have done for DiceDB is fake.

These are the real numbers - https://dzone.com/articles/performance-and-scalability-analy...

Does not match with your benchmarks.

arpitbbhayani12• 1 year ago

The benchmark tool is different. I mentioned the same on my benchmark page.

We had to write a small benchmark utility (membench) ourselves because the long-term metrics that we are optimizing need to be evaluated in a different way.

Also, the scripts, utilities, and infra configurations are mentioned. Feel free to run it.

nylonstrung• 1 year ago

Who is this for? Can you help me explain why and when I'd want to use this in place of redis/dragonfly

losvedir• 1 year ago

I didn't see it in the docs, but I'd want to know the delivery semantics of the pubsub before using this in production. I assume best effort / at most once? Any retries? In what scenarios will the messages be delivered or fail to be delivered?

huntaub2• 1 year ago

What are some example use cases where having the ability for the database to push updates to an application would be helpful (vs. the traditional polling approach)?

zupa-hu2• 1 year ago

One example is when you want to display live data on a website. Could be a dashboard, a chat, or really the whole site. Polling is both slower and more resource hungry.

If it is built into your language/framework, you can completely ignore the problem of updating the client, as it happens automatically.

Hope that makes sense.

huntaub2• 1 year ago

Interesting -- is that normally done with database updates + polling vs. something purpose-built?

deazy2• 1 year ago

Looking at the diceDB code base, I have few questions regarding its design, I'm asking this to understand the project's goals and design rationale. Anyone feel free to help me understand this.

I could be wrong but the primary in-memory storage appears to be a standard Go map with locking. Is this a temporary choice for iterative development, and is there a longer-term plan to adopt a more optimized or custom data structure ?

I find the DiceDB's reactivity mechanism very intriguing, particularly the "re-execution" of the entire watch command (i.e re-running GET.WATCH mykey on key modification), it's an intriguing design choice.

From what I understand is the Eval func executes client side commands this seem to be laying foundation for more complex watch command that can be evaluated before sending notifications to clients.

But I have the following question.

What is the primary motivation behind re-executing the entire command, as opposed to simply notifying clients of a key change (as in Redis Pub/Sub or streams)? Is the intent to simplify client-side logic by handling complex key dependencies on the server?

Given that re-execution seems computationally expensive, especially with multiple watchers or more complex (hypothetical) watch commands, how are potential performance bottlenecks addressed?

How does this "re-execution" approach compare in terms of scalability and consistency to more established methods like server-side logic (e.g., Lua scripts in Redis) or change data capture (CDC) ?

Are there plans to support more complex watch commands beyond GET.WATCH (e.g. JSON.GET.WATCH), and how would re-execution scale in those cases?

I'm curious about the trade-offs considered in choosing this design and how it aligns with the project's overall goals. Any insights into these design decisions would help me understand its use-cases.

Thanks

deazy2• 1 year ago

I was hoping for a response, but no one bothered. I had noted the following when I made that comment and will just wrap up from my end so this could be used by others for reference later.

I'm skeptical that the re-execution approach can scale for complex queries, the latency and throughput improvements would be offseted by the computational cost and bottlenecks introduced for achieving it via its reactivity mechanism (query subscription), this might not work at scale and serve niche use cases.

There are various ways throughput and latency for kv stores can be improved, so bar is really high here.

The messaging with Dice seems unclear and confusing to describe its purpose/use-cases over alternatives, or how it achieves them, which could just be how it's marketed. But it seems to be a collection of ideas and a WIP project.

I think reducing data fetching complexity and complex key dependencies for end clients could be appealing, and it would be great to have it at the KV store level, but there is no reason this type of reactivity can't be implemented on top of various clients for existing KV stores (like Redis). And basic WATCH with transactions are even offered out of the box in them.

Deno kv seem nice but its vendor locked, also there are many others like dragonfly, valkey etc, redis could still work, even something over sqlite can work, deno has a selfhosted kv on top of sqlite - https://github.com/denoland/denokv

Also with dice its creator had made this talk

https://hasgeek.com/rootconf/2024/sub/how-we-made-dicedb-a-t...

From that and the thread so far it seems, they want to make some super cache by building a realtime multi-threaded kv store, improving latency and reducing its read load via its reactivity mechanism. Solving the problem of cache invalidation.

Not sure how this will be achieved but there is no harm in trying. From what is said and shared, rationale behind this design and its tradeoffs are not clear, code could be fixed/improved but providing clarity on this is essential for adoption.

weekendcode2• 1 year ago

From the benchmarks on 4vCPU and num_clients=4, the numbers doesn't look much different.

Reactive looks promising, doesn't look much useful in realworld for a cache. For example, a client subscribes for something and the machines goes down, what happens to reactivity?

999900000999• 1 year ago

I like it!

Anyway to persist data in case of reboots?

That's the only thing missing here.

Is Go the only SDK ?

lucifercr7• 1 year ago

Snapshot functionality is WIP, which can be utilised to persist and replay data between reboots. For now Golang SDK is only one, more SDKs are to be added soon.

Aeolun3• 1 year ago

I feel like this needs a ‘Why DiceDB instead of Redis or Valtio’ section prominently on the homepage.

dkh4• 1 year ago

Did you mean Valkey, or has the js community now managed to shoehorn an entire high-availability database server into a javascript object proxy?

Aeolun3• 1 year ago

It’s only a matter of time xD but yes, I meant Valkey.

I was typing that out and felt like something was wrong but couldn’t put my finger on what.

kiitos5• 1 year ago

There are _so many_ bugs in this code.

One example among many:

https://github.com/DiceDB/dice/blob/0e241a9ca253f17b4d364cdf... defines func ExpandID, which reads from cycleMap without locking the package-global mutex; and func NextID, which writes to cycleMap under a lock of the package-global mutex. So writes are synchronized, but only between each other, and not with reads, so concurrent calls to ExpandID and NextID would race.

This is all fine as a hobby project or whatever, but very far from any kind of production-capable system.

senderista3• 1 year ago

Haven't looked at the code, but enforcing mutual exclusion between writers but not readers can make sense for a single-writer lock-free algorithm.

ignoramous• 1 year ago

single-writer lock-free algorithm

I understand the need for correct lock-free impls: Given OP's description, simply avoiding read mutexes can't be the way to go about it?

kiitos5• 1 year ago

https://github.com/DiceDB/dice/pull/1588

This PR attempted to fix the memory model violation I mentioned in the parent comment, but also added in an extra change that swapped the sync.Mutex to a sync.RWMutex. The PR description claimed 2 benefits: "Eliminates the data race, ensuring thread safety" -- correct! at least to some level; but also "Improves performance by allowing concurrent ExpandID calls, which is likely a common operation" -- which is totally unsubstantiated, and very likely false, as RWMutex is only faster than a regular Mutex under very narrowly-defined load patterns.

In any case, the PR had no kind of test or benchmark to validate either of these claims, so not a great start by the author. But then a maintainer chimed in with a comment that expressed concerns about edge-condition performance details, without any kind of data or evidence, and apparently didn't care about (or know about?) the much more important fixes that the PR made re: data races.

https://github.com/DiceDB/dice/pull/1588#issuecomment-274521...

I tried changing this, but I did not see any benefit in benchmark numbers.

No apparent understanding of the bugs in this code, nor how changes may or may not fix those bugs, nor really how performance is defined or can be meaningfully evaluated.

Again, hobby project or whatever, all good. But the authors and maintainers of this project are clearly, demonstrably, in over their heads on this one.

deadbabe• 1 year ago

I think Postgres can do everything this does and better if you use LISTEN/NOTIFY.

cozzyd• 1 year ago

DiceDB sounds like the name of a joke database that returns random results.

BoorishBears4• 1 year ago

No it doesn't.

kreddor• 1 year ago

It was my first thought as well, before reading the landing page.

graynk3• 1 year ago

Yes it does.

Seems we're in a stalemate, where do we go from here?

retropragma• 1 year ago

Why would I use this over keyspace notifications in redis?

dkh4• 1 year ago

Based on this thread, I'm not sure you would want to use this over keyspace notifications, but I will also say that there comes a point in the maturity of a system when keyspace notifications become a complicated, unreliable, resource-heavy nightmare. They work fine is your needs and scale are limited, but it's definitely not what you want if handling lots of frequent chances across craploads of keys, with complicated logic for who needs them and how they get routed to them, and where it matters if the notification is successfully received.

But certainly you could build something to handle these and most other needs in this realm with mostly just redis, using streams for what needs to be more robust, in tandem with pub/sub, keyspace notifs, etc. in the areas they are suited to.

re-lre-l• 1 year ago

For Modern Hardware fully utilizes underlying core to get higgher throughput and better hardware utilization.

Would be great to disclose details of this one. I'm interested in using what DiceDB achieves higher throughput.

throwaway2037• 1 year ago

FYI: Here is the creator and maintainer's profile: https://github.com/arpitbbhayani

Is there a plan to commercialise this product? (Offer commercial support, features, etc.) I could not find anything obvious from the home page.

robertlagrant• 1 year ago

fully utilizes underlying core to get higgher throughput and better hardware utilization

FYI this is a misspelling of "higher"

alexpadula• 1 year ago

15655 ops a second with a Hetzner CCX23 machine with 4 vCPU and 16GB RAM is rather slow for an in-memory database I hate to say it. You can't blame that on network latency as for example supermassivedb.com is written in go and achieves magnitudes more, actually x20 and it's persisted.. I must investigate the bottlenecks with Dice.

rednafi• 1 year ago

Database as a transport?

DiceDB

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