Adjust block max size for Flash

[Linh Tran Tuan]

@unrealhoang @Permagate

As I research a lot on leveldb/rocksdb sst file, I recommend setting Block Max Size to at least 8MB and at most 32MB for Flash raft store.

[Linh Tran Tuan]

Example:

grocksdb/options_block_based_table.go

Line 104 in b52a8c8

 func (opts *BlockBasedTableOptions) SetBlockSize(blockSize int) { 

[Linh Tran Tuan]

Sorry for my previous recommend. I would correct it: disable filter might help in reduce io, sst file size.

I think in most of cases , hit rate is pretty high. So we might not need bloom filter or any kind of filter.