>>> Jürgen Baier <[email protected]> schrieb am 07.10.2021 um 08:07 in
Nachricht
<[email protected]>:
> Hi,
> 
> I'm using LMDB for mapping MD5 hash codes to some data. I noticed that a 
> virtualized environment (Xen/Windows on our own servers and AWS/Windows) 
> slows down LMDB significantly (e.g. a certain workload is executed in 30 
> minutes on a local machine vs. 15 hours on AWS).

I don't know whether Winows uses huge pages at all, but AFAIK huge pages are
unavaiable under Xen.
Maybe that makes a difference for large memory configurations (in addition to
the other things mentioned).
The other thing is whether your VM has a dedicated CPU or an "overcommitted"
shared CPU.

However 15 hours vs. 30 minutes sounds drastic.

> 
> My application also has an implementation in SQLite which is slower than 
> LMDB on a local machine. But its performance is similar on AWS. The 
> rough numbers are something like
> 
> Local:
> 
> - LMDB: 30 minutes
> - SQLite: 45 minutes
> 
> AWS:
> 
> - LMDB: 15 hours
> - SQLite: 50 minutes
> 
> I wanted to ask if there is something I can do to speed up LMDB on AWS? 
> Maybe I'm missing something obvious.
> 
> Thanks,
> 
> Jürgen
> 
> -- 
> Juergen Baier


Reply via email to