Candidate databse instance: database native time

[shlomi-noach]

This PR resubmits #587 with only the actual code change. See discussion on #587 and #585

cc @ndelnano

[nickdelnano]

thank you @shlomi-noach !

[nickdelnano]

Is a date for the next release planned? The dates of the last several releases does not look like there is a fixed schedule.

[shlomi-noach]

You are correct, there is no fixed schedule. But a kind reminder helps!

[shlomi-noach]

While this may work well for sqlite, this breaks MySQL for servers with non-UTC timezone. Looking into.

[shlomi-noach]

We need to juggle between three different scenarios:

• MySQL backend (has timezone notion)
• Sqlite (does not have timezone notion)
• raft messages (register-candidate can apply by reading historical raft event, the value of now() becomes meaningless)

[shlomi-noach]

@ndelnano I ended up solving the problem in a different way: reading the timestamp as a string from the database, then feeding it back.
Would you care to test this PR works for you? Works for me, on sqlite and MySQL on different timezone boxes.

[nickdelnano]

@shlomi-noach I have tested and it does indeed work for me. Thanks again!

[shlomi-noach]

OK good, this has been deployed to staging and in production for a while. I'll let our daily tests run and then merge.