MongoDB writes to be safe/verified by default

http://blog.mongodb.org/post/36666163412/introducing-mongoclient?yey

by mrkurt • 14 years ago

68 32 14 years ago

blog.mongodb.org

This seems like a very sane way of handling this particular issue. I know it's cool to hate on MongoDB these days, but I've always liked the way they built their product. Maybe at ridiculous scale it's not as awesome, but it's been pretty decent for me on the small projects I used it on.

davidw• 14 years ago

Pretty much anything can be made to work for small projects. Even stodgy old SQL projects like Postgres which pay a lot of attention to being correct and doing their damndest to preserve your data.

smoyer• 14 years ago

Gasp ... I'm just about to use "stodgy old PostgreSQL" in a new project. I guess I'm old enough now that perhaps I'm stodgy myself.

ukd12• 14 years ago

I think this seems a pretty insane way of doing it; why not change the default behavior instead of making another driver with a separate name as well as keeping the old one too?

This is likely to be super confusing to new users; rumours that it's write safe and all the common examples will be fore the old driver...

IMHO they should have altered the defaults; people who require the extra performance will likely be the ones reading the changelogs / docs / these posts and notice.

msbarnett• 14 years ago

> I think this seems a pretty insane way of doing it; why not change the default behavior instead of making another driver with a separate name as well as keeping the old one too?

Because, as they clearly explain in their rationale, that would break compatibility with all of the existing software out there that relies on the current semantics.

Thou Shalt Not Break Working Code is the first rule of building software that other software relies on.

They're deprecating but retaining the old driver to give people a transition period in which to modify their software instead of kicking them in the teeth immediately or forcing them to hold off on upgrading. That's the mature approach to fixing mistakes that people nonetheless built assumptions around.

MichaelGG2• 14 years ago

If it's properly deprecated, the old constructor should cause a compiler warning with a message explaining the issue. This way, old and new users of the new library will get the message, even if the sample uses the old constructor.

At least in languages that support that feature (.NET, Java, C++ with some extensions).

A more aggressive approach, used e.g. in the CLR for really serious problems (like the improper HMAC calculation bug, or background threads not aborting in CLR < 2.0) give you a warning and allow you to switch it off via config, so no code change is required, but everyone gets the "fix".

rdtsc• 14 years ago

Yes everyone here hates mongo because that is cool and they are all irrational, not because up until, well ... now, it had been calling itself a 'database' product while specifically defaulting to doing the least possible to make sure your data actually hits the disk. But hey, it looks good in benchmarks, and it is WebScale(tm) and anyone who hates that kind of thing is just an irrational hater.

darkarmani• 14 years ago

> it had been calling itself a 'database' product while specifically defaulting to doing the least possible to make sure your data actually hits the disk

Being a database doesn't mean you have to persist on disk. There is nothing wrong with in-memory databases. If you thought they were giving you persistence guarantees, then yeah, you would have a gripe.

willholloway• 14 years ago

Mongo made it extremely easy for me to create local caches of JSON api data. I didn't want to go through the hassle of mapping postgres schema or dealing with it's hstore data type.

I was then able to write a quick script to copy my mongo database over to elasticsearch. It was a joy.

six• 14 years ago

Sadly it seems that the "ubuntu generation" of people who don't RTFM have won out.

The sheer amount of recent MongoDB hate has been extremely annoying, not to mention the half-assed reasons for justifying it - we've learned a lot of things from running MongoDB at scale, and none of them are what the haters usually whine about.

meghan• 14 years ago

Glad that you are having success with MongoDB at scale. Have you considered sharing your experiences? Would be really helpful for others to learn from you.

biscarch• 14 years ago

Seconded. I'd love to see a post about your experiences.

mrinterweb• 14 years ago

Kind of take some offence to you using "ubuntu generation" as a pejorative, but you're right about people hating on MongoDB because it is cool to hate on MongoDB. I'm sure that most people spreading the fud have little to no experience with it.

I think that MongoDB has got a lot of attention because its brand of NoSQL is one of the closest neighbours to RDBMS. I believe a lot of people may have dabbled with mongo and they might have walked away realizing that NoSQL is not 100% sugar plums and lollipops as evangelized. There are trade-offs between different NoSQL databases and RDBMS, and Mongo is no exception. Personally, I really like MongoDB and continue to use it.

MichaelGG2• 14 years ago

Still seems like an awfully long time to switch to proper defaults -- 3 and a half years?

wmf• 14 years ago

They had to wait until their unsafe benchmarks had killed off the competition.

malkia• 14 years ago

LOOOOL!

rogerbinns3• 14 years ago

I think the single biggest mistake they made was calling the option "safe". That is obviously ludicrous! They should have called it exactly what it is - "async".

fruchtose• 14 years ago

Don't you mean safe mode is the synchronous version? The original default was asynchronous error checking.

rogerbinns3• 14 years ago

What I mean is that instead of calling it "safe" they should have called it "async". "safe" is the wrong terminology to use.

ericcholis• 14 years ago

I know that the case is for safe is obvious, and I'm happy about the switch. However, read the manual before getting your CAT6 in a twist. I really want to use Postgres for an upcoming project, so I plan to read everything I can about it. A sane developer tests, reads, tests again, swears a lot, drinks coffee, and reads again. Try to find every damn pitfall you can digest. You will spend an exorbitant amount of time reading, but you'll be better for it.

dkhenry• 14 years ago

So for any of us who have been responsible and actually used the fire and forget behavior of the previous driver here is the API call that you can use to revert back

http://api.mongodb.org/java/2.6/com/mongodb/Mongo.html#setWr...

jeffdavis• 14 years ago

A good decision. I know backwards compatibility is important, but safe defaults are an important aspect of usability.

Also, it's difficult to change something after defending it for a while. That's a promising sign.

websauce• 14 years ago

I switched to MongoDB because devnull is webscale. Why take the speed of devnull away from new users?

ericflo• 14 years ago

This is fantastic news!

nviennot• 14 years ago

That reminds me of https://github.com/mongoid/moped/pull/92

MongoDB writes to be safe/verified by default

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