Vitess production testing/onboarding

[bbeaudreault]

As we look to bring more users onto vitess, one area we can smooth over is helping the new user easily validate whether vitess will work in their system. There are a few areas I think any new person should concern themselves with:

1. Query compatibility
2. Sharding methodology
3. Load testing

When I was doing this process a few months ago, I wrote a binary called vtparse that could do all of the validation parts for the first item and output any errors found. This got the job done, but was clunky and is now outdated.

@sougou believes vtcombo could handle the first 2 parts. We'd need to provide some ease-of-access improvements to it:

• Allow calling with a single query or a sql file filled with queries.
• Allow loading existing schema into it with a sql file
• Aggregate output a bit, such as group errors by type (parse error, plan error, etc). It would also be nice to output how many queries were single shard vs multi-shard/db.

Finally, all of this should be documented in an Onboarding document.

cc @o1egl @derekperkins

[sougou]

I've produced this video https://youtu.be/71nTBafPtcM, which should address 1 & 2.