* Add UI warning for time drift >30 seconds
* Yellow time drift warning & better warning message
* Set warning threshold to 30 sec
* Include changed assets
Instead, just make the anchoring part of the internal regex. This helps because
some users will want to read back the `Value` field and expect it to be the
same as the input value (e.g. some tests in Cortex), or use the value in
another context which is already expected to add its own anchoring, leading to
superfluous double anchoring (such as when we translate matchers into remote
read request matchers).
Instead or only printing the help message, which is not always helpful.
For example, when upgrading from prometheus v1, the retention time value
format has changed and now only accepts one unit (e.g. "15d") where it
previously allowed more complex strings (e.g. "360h0m0s").
This commit provides the error message as an explanation for the parsing
failure.
The timer semantics is really hard. The simple pattern as given in the
godoc for the time package assumes we are not elsewhere consuming from
the timer's channel. However, exactly that can happen here with the
right sequence of events. Thus, we have to drain the channel only if
it has something to drain.
This means that if there is no stale marker, only the usual staleness
delta (5m) applies.
It has occured to me that there is an oddity in the heurestic. It works
fine as long as you have 2 points within the last 5m, but breaks down
when the time window advances to the point where you have just 1 point.
Consider you had points at t=0 and t=10. With the heurestic it goes stale
at t=51, up until t=300. However from t=301 until t=310 we only
see the t=10 point and the series comes back to life. That is not
desirable.
I don't see a way to keep this form of heurestic working given this
issue, so thus I'm removing it.
* Re-add contexts to storage.Storage.Querier()
These are needed when replacing the storage by a multi-tenant
implementation where the tenant is stored in the context.
The 1.x query interfaces already had contexts, but they got lost in 2.x.
* Convert promql.Engine to use native contexts
