[KAFKA-2607] Review `Time` interface and its usage

• Type: Improvement
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.1.0
• Labels: newbie
• Assignee: Aleksei Kogan
• Reporter: Ismael Juma
• Reviewer: Ismael Juma
• Created: 02/Oct/15 12:15
• Updated: Yesterday 19:12

Description

Two of `Time` interface's methods are `milliseconds` and `nanoseconds` which are implemented in `SystemTime` as follows:

    @Override
    public long milliseconds() {
        return System.currentTimeMillis();
    }

    @Override
    public long nanoseconds() {
        return System.nanoTime();
    }

The issue with this interface is that it makes it seem that the difference is about the unit (`ms` versus `ns`) whereas it's much more than that:

https://blogs.oracle.com/dholmes/entry/inside_the_hotspot_vm_clocks

We should probably change the names of the methods and review our usage to see if we're using the right one in the various places.

Issue Links

• is blocked by: KAFKA-2247 Merge kafka.utils.Time and kafka.common.utils.Time
• is blocked by: KAFKA-2606 Remove kafka.utils.Time in favour of o.a.kafka.common.utils.Time
• links to: GitHub Pull Request #837
• links to: GitHub Pull Request #5958