Is it safe to use the node v8 options in a production environment?

Question

node.js provides lower layer V8 options too. These options are very low layer like garbage collection or heap algo.

# node --v8-options

Options:
 --harmony_typeof (enable harmony semantics for typeof)
    type: bool  default: false
 --harmony_proxies (enable harmony proxies)
    type: bool  default: false
 --harmony_weakmaps (enable harmony weak maps)
    type: bool  default: false
 --harmony_block_scoping (enable harmony block scoping)
    type: bool  default: false

Although I can see most of them are not meant for frequent use.

If I see some option useful, can I use them safely without any fear of code change in V8 engine release upgrade?

Answer 1

The harmony options are not yet part of an official ECMA script standard, you can checkout some of the ongoing discussions here. I don't keep up with the work on the ES6 standard, it is possible that some of these features will not be changed significantly once ES6 arrives, but I would say there is still a fear of code change. If you choose to still implement any, I would recommend keeping up with the V8 changes to see if any of their interfaces undergo modification.

Edit: Re-reading your post, it appears you're talking about all the options in general. I would still stick by my statement above regarding the Harmony options for now. Other options may come down to a per-option basis. You might be best posting to the V8 discussion list when you come across one that you're not sure of.

Answer 2

Most of the V8 options are only there for debugging purposes. If you report a bug that is triggered by a flag the most likely result is that the flag will be removed. However, the following flags are supposed to work:

--max-old-space-size (not for really small sizes) --harmony (activates all Harmony features but meaning of that may change)