Recent macOS versions zero out memory on free, which improves the efficacy of memory compression. Apparently it’s a net performance gain in the average case

A few years back I patched the memory allocator used by the Cloudflare Workers runtime to overwrite all memory with a static byte pattern on free, so that uninitialized allocations contain nothing interesting.

Note that many malloc implementations will do this for you given an appropriate environment, e.g. setting MALLOC_CONF to opt.junk=free will do this on FreeBSD.

> OpenBSD uses 0xdb to fill newly allocated memory and 0xdf to fill memory upon being freed. This helps developers catch "use-before-initialization" (seeing 0xdb) and "use-after-free" (seeing 0xdf) bugs quickly.

Looks like this is the default in OpenBSD.

You know, I never even considered doing that but it makes sense; whatever overhead that's incurred by doing that static byte pattern is still almost certainly minuscule compared to the overhead of something like a garbage collector.

FYI, at least in C/C++, the compiler is free to throw away assignments to any memory pointed to by a pointer if said pointer is about to be passed to free(), so depending on how you did this, no perf impact could have been because your compiler removed the assignment. This will even affect a call to memset()

see here: https://godbolt.org/z/rMa8MbYox

From my experience, Mongo DB's entire raison d'etre is "laziness".

* Don't worry about a schema.

* Don't worry about persistence or durability.

* Don't worry about reads or writes.

* Don't worry about connectivity.

This is basically the entire philosophy, so it's not surprising at all that users would also not worry about basic security.

A highly cited reason for using mongo is that people would rather not figure out a schema. (N=3/3 for “serious” orgs I know using mongo).

That sort of inclination to push off doing the right thing now to save yourself a headache down the line probably overlaps with “let’s just make the db publicly exposed” instead of doing the work of setting up an internal network to save yourself a headache down the line.

Are you guys serious with these takes?

You very often have both NoSQL and SQL at scale.

NoSQL is used for high availability of data at scale - iMessage famously uses it for message threads, EA famously uses it for gaming matchmaking.

What you do is have both SQL and NoSQL. The NoSQL is basically caches of resources for high availability. Imagine you are making a social media app... Yes of course you have a SQL database that stores all the data, but you maintain API caches of posts in NoSQL.

Why? This gets to some of your other black vs white insults: NoSQL is typically WAY FASTER than SQL. That's why you use it. It's way faster to read a JSON file from a hard drive than it is to query a SQL database, always has been. So why not use NoSQL for EVERYTHING? Well, because you have duplicated data everywhere since it's not relational, it's just giant caches essentially. You also will get slow queries when the documents get huge.

Anyway you need both. It's not an either/or thing. I cannot believe this many years later people do not know the purpose of SQL and NoSQL and do not understand that it is not a competition at all. You want both!

The article links to a shodan scan reporting 213K exposed instances https://www.shodan.io/search?query=Product%3A%22MongoDB%22

My university has one exposed to the internet, and it's still not patched. Everyone is on holiday and I have no idea who to contact.

It could be because when you leave an SQL server exposed it often turns into much worse things. For example, without additional configuration, PostgreSQL will default into a configuration that can own the entire host machine. There is probably some obscure feature that allows system process management, uploading a shell script or something else that isn't disabled by default.

The end result is "everyone" kind of knows that if you put a PostgreSQL instance up publicly facing without a password or with a weak/default password, it will be popped in minutes and you'll find out about it because the attackers are lazy and just running crypto-mine malware, etc.

For a long time, the default install had it binding to all interfaces and with authentication disabled.

often. lots of data leaks happened because of this. people spin it up in a cloud vm and forget it has a public ip all the time.

What would you prefer them to say?

Easy replication. I suppose it's faster than Postgres's JSONB, too.

I would rather not use it, but I see that there are legitimate cases where MongoDB or DynamoDB is a technically appropriate choice.

Right? When they came out, it was all about NoSQL, which then turned out only mean key-value database, whom are plentiful.

because it is "web scale"

ref: https://www.youtube.com/watch?v=b2F-DItXtZs

This is a nasty ad repositorium datorum argumentation which I cannot tolerate.

I mean giving everyone footguns and you'll find that is unavoidable forever. Thoughts and prayers to the Mongo devs until we migrate to a language that prevents this error.

TLDR: Blame logs not NoSQL.

Almost always when you hear about emails or payment info leaking (or when Twitter stored passwords in plaintext lol) it's from logs. And a lot of times logs are in NoSQL because it is only ever needed in that same JSON format and in a very highly available way (all you Heroku users tailing logs all day, yw) and then almost nobody encrypts phone numbers and emails etc. whenever those end up in logs.

There's basically no security around logs actually. They're just like snapshots of the backend data being sent around and nobody ever cares about it.

Anyway it has nothing to do with the choice to use NoSQL, it has more to do with how neglected security is around it.

Btw in case you are wondering in both the Twitter plaintext password case and in the Rainbow Six Siege data leak you mention were both logs that leaked. NoSQL backed logs sure, but it's more about the data security around logging IMO.

I read that hack was made possible by Ubisoft’s support staff taking bribes.

That's what calloc() is for

It takes time to zero out memory.