On: Scaling MongoDB at Mailbox

[jessaustin]

Interesting:

...a single Python process using gevent and pymongo can copy a large MongoDB collection in half the time that mongodump (written in C++) takes, even when the MongoDB client and server are on the same machine.

[MBCook → jessaustin]

I would guess this is for the reason posted in the article: the Python code is multithreaded (sort of, gevent) but the C++ code is only single threaded.

[jessaustin → MBCook]

Sure, but that seems to suggest a meta-reason: the standard utility included with the package isn't asynchronous [sort of orthogonal to threadedness] because it would be a PITA to write an asynchronous utility in C++.

[leif → jessaustin]

That's not true, I've had no trouble writing very fast threaded C++ programs with the mongo client.

[jessaustin → leif]

1. That's not what I said.

2. I'm sure the Mongo devs would accept pull requests for mongodump.

[leif → jessaustin]

1. > it would be a PITA to write an asynchronous utility in C++

2. Doubt it, and there's no reason for me to write one for them.

[jessaustin → leif]

Asynchronous ≠ multithreaded. TFA actually tried both ways, measured the difference, and found async to be much faster.