Memcached 1.6

https://github.com/memcached/memcached/wiki/ReleaseNotes160

by nrr • 6 years ago

110 46 6 years ago

haolez3• 6 years ago

I have a trading bot that consolidates a lot of price information in order to make decisions. I'm currently using Redis due to data structures (lists and scores) and Pub/Sub.

I wonder if memcached would give me performance benefits and lower my CPU costs.

manigandham5• 6 years ago

CPU is cheap and memcached has no advanced data structures. If you're using them then you'll probably have to reimplement everything yourself in memcached with less efficiency.

henriquez2• 6 years ago

You can always just JSON-encode whatever you’re putting in there and decode on the way out. Though I couldn’t imagine using it for pub/sub like the parent commenter is doing with redis.

dormando3• 6 years ago

Mind giving some examples in more detail about how you make use of lists/scores?

haolez3• 6 years ago

Pub/Sub is easily replaceable. I use lists and scores to store orders from orderbooks, where the prices are the scores. Then I can order by price.

It's simple, but I have like 400 updates per second.

jasonwatkinspdx• 6 years ago

You'll get a bunch of garbage answers here to be frank, from people who never put more than trivial load through both.

Memcache blows redis out of the water in terms of raw throughput and latency, like it's not even remotely close on modern lots of cores and big memory machines.

Redis has a more feature rich api, but has fundamentally hobbled itself on a root hash table and concurrency implementation that is circa 1990.

Give memcached a try, even if it means you implement some stuff you currently defer to redis ops. Measure it. Look at the code bases. Make up your own mind about performance and which actually makes your code simpler.

dijit• 6 years ago

http://antirez.com/news/94

TL;DR: Redis is just doing different things, and the slab allocator is pretty efficient in regards to performance but not memory usage.

haolez3• 6 years ago

Thanks. I'll make sure to create a PoC and post back here.

dleslie• 6 years ago

This was the first non-sql datastorage I used for online services; a lifetime ago. Glad to see that it is still maintained.

qeternity• 6 years ago

I wouldn't be surprised if there is more data cached by memcached than redis with all the massive players using. Hardly a dead project.

henriquez2• 6 years ago

I still use Memcache in a handful of old PHP projects I’ve been keeping on life support since the mid 2000s. I’m also glad it’s being maintained! It’s perfectly fine at what it was designed to do.

coleifer• 6 years ago

Memcached doesn't pander or resort to marketing to achieve a userbase (compare to redis/labs). It's a great piece of software engineering and I absolutely respect that there's no gimmick, no bullshit. Just a lot of hard work given away for free. Great work!

dormando3• 6 years ago

Thanks!

vosper• 6 years ago

Memcached doesn't pander or resort to marketing to achieve a userbase (compare to redis/labs)

I think this is pretty unfair to Redis. Redis has a lot more features (tell me which ones you think are pandering, and to whom?), is free for the vast majority of what people want to use it for, and the attempt to make some money through Redis Labs is pretty recent in the scheme of things. If that helps with the continued development of Redis I have no problem with it.

cletus• 6 years ago

While I don't want to take anything away from memcached, I'm puzzled by the swipe at Redis. Whatever marketing you're referring to, Redis supports some pretty useful data structures that make some pretty common query patterns trivial (eg top-N queries) and does it with a small, elegant core of some of the most readable code ever produced.

Memcache OTOH is a fairly simple KV cache. It seems to be pretty decent. Neither of these supplants the other however. Hence my puzzlement. It just seems out of place, unnecessary and doesn't really add anything.

philippz• 6 years ago

Been using memcached for >7 years now. Just thank you! It's been adding great benefits to almost all of my projects.

darknrgy• 6 years ago

Memcached is state of the art for caching and most of the big players on the internet use it. Nice work, dormando.

ksec• 6 years ago

It is interesting to see how Memcached and Redis, what was once competing in the same space, diverge in development. Redis continue to add features on top of features, it isn't bloat by any means, but it is still a lot more than say Redis 2.x. While Memcached stayed pretty much the same as memcahched 1.4, which was released over a decade ago. Optimising every single bit out of it and allow cache to be extended to SSD.

Boring Tech is Good. Memcached should be added to that list.

Edit: Release Note Mentioned Netflix, I wonder what they use it for.

threeseed2• 6 years ago

Boring Tech is Good

It's fine if all you are doing is boring things.

But often there are use cases where a simple key/value store just isn't going to cut it.

And I for one am glad to have Redis as a solid, well-engineered alternative.

gdy• 6 years ago

You can do boring things with cool tech and cool things with boring tech. I'm not sure if they even correlate.

Rafuino• 6 years ago

Regarding Netflix, here's a big usage of theirs, which is the Extstore (external flash storage) the Github page refers to. They probably use it beyond this, but it's a good technical article to sink your teeth into.

https://netflixtechblog.com/evolution-of-application-data-ca...

subsaharancoder• 6 years ago

Snapchat is one of the largest if not the largest user of memcached on GCP, a few years ago they were +100TB and growing like a weed!!

Tostino• 6 years ago

That seems horrible.

kator• 6 years ago

What I like about Memcached is it's just that, it works, written in C, oh and my goodness uses Perl tests!

It's not re-written every other year in the latest hot language. It chugs along, without embarrassment, doing one thing amazingly well over 17 years...

bigiain• 6 years ago

It used to be written in Perl, back in the day... I suspect some of those tests are quite likely to be from back then.

I smiled when I read the title, thinking "How cool! Something I was using at a job I left ~16 years ago has _finally_ made it to version 1.6!" :-)

(I suspect the old LiveJournal Perl code probably didn't have it's version numbers carry over into this somewhat more modern version...)

threeseed2• 6 years ago

It's not re-written every other year in the latest hot language

What is with all of the weird sniping in this thread ?

There are legitimate reasons why people move to Rust and similar languages e.g. security, maintainability.

manigandham5• 6 years ago

"It's not re-written every other year in the latest hot language."

What project does this?

qatanah• 6 years ago

Redis tests are written in tcl! both perl and tcl are awesome!

pachico5• 6 years ago

This is not a rhetorical question, I'm asking our of curiosity/ignorance. If you were about to start a new project, for what reasons would you choose Memcached over Redis? Or probably better said, for which use cases?

rawoke083600• 6 years ago

I grew up with memcached and it certainly has way less features than redis, but nothing is simpler. For linux+php anyway. From setup to usage.

teej• 6 years ago

Redis. Back in the day when I ran memcached with the rest of the cool kids, I always wanted something like SADD and LPUSH. Redis is a realization of that vision and using it is always a delight to me.

mrweasel2• 6 years ago

I don't really see those two projects as solving the same problems.

Memcache is for caching only, it's very good at it, there is basically no administrative overhead and people (i.e. other developers) know that if you stuff data into memcache, you should be prepared to lose it.

Redis is, to me at least, much more akin to "shared data structures as a service". Sure it's also a key value store, where I could cache data, but I could do that with MySQL as well. I look to Redis when I need to have data shared between components, and sometimes a key value store happens to be the best solution, other times it may be pub/sub.

pachico5• 6 years ago

Thanks for your answer. I can hardly see Redis as a hard to admin software - vanilla installation should work in most (if not all) scenarios, honestly. This is why I'm asking because, giving that Redis has a great number of extra features and superb performance, it would be hard to justify, at least for me, to choose Memcached. Worst case scenario, you don't use all those extra features. Or am I missing anything?

philliphaydon• 6 years ago

I would go Redis because I feel Memcached clients in .NET have more or less been abandoned. The main one used for .net core causes problems and I cannot narrow down why :(

mhd• 6 years ago

I think the default Javascript one still can't connect properly to memcache run over a domain socket. So yeah, there's a lot of rust in the client-space.

steve_adams_86• 6 years ago

There are definitely reasons to consider.

At the highest level, I'd say Redis is a swiss army knife and Memcached is a simple pocket knife. Sometimes you really want the swiss army knife, sometimes all of that stuff is just in the way. Memcached is super simple and basic, and that's what I want to lean towards in the building blocks of my software.

Looking closer, Redis isn't multithreaded while Memcached is. This means Memcached can scale vertically by scaling compute power in a single instance. Redis isn't well-suited to that. If you're just using a key-value store with zero frills and you run a monolithic app on a single instance, Memcached is going to take you a lot further. A ton of people still run their web applications this way.

Having said that, Redis scales horizontally very easily and nicely. You can create replicas of a primary Redis instance to create super high performance/availability clusters. I'd say the lack of multithreading is a non-issue if you know how to manage Redis this way and your infrastructure allows for it.

Beyond that, if you do need the features Redis offers (scripting, geospatial support, pub/sub, etc) then Memcached is pretty much off the table.

I'm sure there are things I'm missing, but these are the key items that come to mind. They're definitely different! I wouldn't say Redis is the de-facto solution, although I love it and use it a lot.

Memcached 1.6

Related Stories