Currently, if a series stops to exist, its head chunk will be kept
open for an hour. That prevents it from being persisted. Which
prevents it from being evicted. Which prevents the series from being
archived.
Most of the time, once no sample has been added to a series within the
staleness limit, we can be pretty confident that this series will not
receive samples anymore. The whole chain as described above can be
started after 5m instead of 1h. In the relaxed case, this doesn't
change a lot as the head chunk timeout is only checked during series
maintenance, and usually, a series is only maintained every six
hours. However, there is the typical scenario where a large service is
deployed, the deoply turns out to be bad, and then it is deployed
again within minutes, and quite quickly the number of time series has
tripled. That's the point where the Prometheus server is stressed and
switches (rightfully) into rushed mode. In that mode, time series are
processed as quickly as possible, but all of that is in vein if all of
those recently ended time series cannot be persisted yet for another
hour. In that scenario, this change will help most, and it's exactly
the scenario where help is most desperately needed.
The staticcheck warns about testing.T usage in goroutines. Moving the
t.Fatal* calls to the main thread showed immediately that this is a good
practice, as one of the test setups didn't work.
* Fixed int64 overflow for timestamp in v1/api parseDuration and parseTime
This led to unexpected results on wrong query with "(...)&start=148966367200.372&end=1489667272.372"
That query is wrong because of `start > end` but actually internal int64 overflow caused start to be something around MinInt64 (huge negative value) and was passing validation.
BTW: Not sure if negative timestamp makes sense even.. But model.Earliest is actually MinInt64, can someone explain me why?
Signed-off-by: Bartek Plotka <bwplotka@gmail.com>
* Added missing trailing periods on comments.
Signed-off-by: Bartek Plotka <bwplotka@gmail.com>
* MOved to only `<` and `>`. Removed equal.
Signed-off-by: Bartek Plotka <bwplotka@gmail.com>
Expose buildQueryUrl, refactor dispatch to use
buildQueryUrl will allow users to execute queries over the range of an
existing graph. This will be helpful to select data series they wish to
annotate the graph with, for example.
