IGFS cache configuration.

[Vladimir Ozerov <vo...@gridgain.com>]

Hi all,

I was thinking more about our file system configuration. Currently in order
to configure IGFS user have to specify at least three things:
1) Cache configuration for metadata;
2) Cache configuration for actual data;
3) IGFS configuration which wires all these things together.

Furthermore, configurations from p.1 and p.2 have some limitations. E.g. we
force user to make metadata cache REPLICATED, we force him to set specific
eviction policy for data cache, etc..

All these configuration settings and their inter-relations seem to be
pretty complex . In addition, we force user to be aware of IGFS
implementation details, while normally user would like to configure only
very few things (say, maximum FS size, DUAL/PRIMARY mode, etc.), or use all
defaults.

What if we add meta and data cache configuration beans directly to
IgfsConfiguration and initialize them with sensible defaults? Then, during
Ignite startup we just pull these configurations from Igfs config and add
to regular cache configurations. This way user will be able to start using
GGFS with almost no configuration.
But if we have want to user some specific cache config, he can always
define another CacheConfiguration bean and set whatever he like to it.

Thoughts?

Vladimir.