ESQL: Pin now on all data nodes

[nik9000]

Description

ESQL currently uses system.currentTimeMillis for the query start time but it really should pin that at query start. See: https://github.com/elastic/elasticsearch/blob/main/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/session/Configuration.java#L163

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[luigidellaquila]

We already have a "now" in the configuration, I guess we can use it right away

[nik9000]

We already have a "now" in the configuration, I guess we can use it right away

Oh oops. I guess what I really mean is absoluteStartedTimeInMillis - but to be honest those should probably be the same. I'm not sure why our now is Zoned. But that's a thing for another day.

[luigidellaquila]

Sorry, my fault, too many StartedTime things in there...
I think the Zoned is QL legacy code.
I have no idea of why absoluteStartedTimeInMillis and getQueryStartTimeNanos are different (apart from the precision), but now has nanosecond precision as far as I can see, and both queryStartTimeNanos and now are always instantiated at the same time, so I agree with you, they could be the same thing.

[bpintea]

@luigidellaquila should this be closed after #113777?

[luigidellaquila]

I think so, thanks @bpintea, closing