I have carefully calculate the demand of memory and the cost.
1) As traffic grows, memory consumption does not growing, because of node.js?
I was running another site ourjs.com, sometime I saw 100~200 active users on site at the same time (from Google Analytic), but the memory used of ourjs thread is still less than 100Mb, almost the same when there is no traffic.
2) JSON Data doesn't consumption much memory, I post one article per day on my ourjs, now there are more than 450 articles, I think I can use this framework for 10 years.
3) There maybe memory limitation in V8 but I don't think the blog/website will exceed this limit, maybe I will split into several threads in future if I really run into this issue.
PS: English is a foreign language for me, if you can point out any grammatical errors, I will be very happy too.