The Su-30SM is a Russian Air Force version of the Su-30MKI that has long been exported (to India, Algeria, and Malaysia). For the last two decades Russian defense manufacturers have survived on exports. The Russian military halted most procurement spending after the Soviet Union collapsed in 1991 (largely from financial mismanagement).
In the last decade the Russian military has gradually resumed buying. Initially the Russian military could not afford the best stuff (like the Su-30MKI). But that has changed, and now the Russian military is catching up. This is the first Su-30 model for the Russian Air Force that uses thrust vectoring (the ability of the engine to direct its exhaust a bit and enhance maneuverability).
Both the Su-30SM and Su-30MKI are most similar to the two seat American F-15E fighter-bomber. The Su-30MKI, even though equipped with Western electronics, costs less than $40 million each, about half of what an equivalent F-15 costs. The Russian version will have Russian electronics and other Russian made gear but otherwise be nearly identical to the Su-30MKI. The Su-30MKI/SM can carry more than eight tons of bombs and hit targets over 1,500 kilometers away. The Su-30SM is able to use a large range of missiles and smart bombs.