Home / server / Questions / 401301
Accepted
ledy
Asked: 2012-06-23 04:35:23 +0800 CST

mongodb eating 48G in 1min

  • 772

In mongodb i work with this collection:

Size     55.93g 
Data Size    39.82g
Storage Size 41.08g 
Extents  53 
Indexes  4 
Index Size   9.64g

It takes few seconds of mongdb being up with this single collection and all 48GB RAM on the dedicated server are gone.

That's worse because there is also a mysqld+nginx/fcgi on this machine which should be allowed to use at least 24GB together. I.e. remaining 24GB, enough for the mongod!

However, it does not share in a fair way. Everybody says that the memory for mongod is managed by OS and releases unneccessary space for other processes if they demand RAM. On my machine it is not releasing RAM. What's wrong?

free

             total       used       free     shared    buffers     cached`
Mem:      49559136   49403908     155228          0      57284   47247564
-/+ buffers/cache:    2099060   47460076
Swap:      8008392        164    8008228
memory mongodb

1 Answers

  1. Best Answer

    As you see in your output of free, 47460076 byte are cached. They are freed if needed. Don't worry you have plenty of memory and mongoDB won't eat it. It just takes a bit of ram that is immediately freed when other applications really need it.

    • 7