Some benchmarks for HEAD and allocate the correct slice size in LabelValues , we already know what it'll be
This is ~15% time improvement, and ~25% allocation improvement:
```
benchmark old ns/op new ns/op delta
BenchmarkHeadPostingForMatchers-4 74452 63514 -14.69%
benchmark old allocs new allocs delta
BenchmarkHeadPostingForMatchers-4 20 13 -35.00%
benchmark old bytes new bytes delta
BenchmarkHeadPostingForMatchers-4 5425 3137 -42.18%
```
Signed-off-by: Thomas Jackson <jacksontj.89@gmail.com>
This reverts commit 98fe30438c.
After some discussion, it was concluded that we want the full
`prometheus_tsdb_...` prefix hardcoded in the library.
Signed-off-by: beorn7 <beorn@soundcloud.com>
This fixes various issues when initializing the head time range
under different starting conditions.
Signed-off-by: Fabian Reinartz <freinartz@google.com>
Blocks are half-open intervals [a, b), while all other intervals
(chunks, head, ...) are closed intervals [a, b].
Make that distinction explicit by defining `OverlapsClosedInterval()`
methods for blocks and chunks, and using them in place of the more
generic `intervalOverlap()` function.
This change also fixes `db.Querier()` and `db.Delete()`, which could
previously return one extraneous block at the end of the specified
interval.
Signed-off-by: Benoît Knecht <benoit.knecht@fsfe.org>
This has been a frequent source of debugging pain since errors are
potentially delayed to a much later point. They bubble up in an
unrelated execution path.
We were determining a chunk's end time once it was one quarter full to
compute it so all chunks have uniform number of samples.
This accidentally skipped the case where series started near the end of
a chunk range/block and never reached that threshold. As a result they
got persisted but were continued across the range.
This resulted in corrupted persisted data.
The postings list index may point to series that no longer
exist during garbage collection. This clarifies that this is valid
behavior.
It would be possible, though more complex, to always keep them in sync.
However, series existance means nothing in itself as the queried time
range defines whether there's actual data. Thus our definition is sane
overall as long as drift is kept small.
This commit introduces error returns in various places and is explicit
about closing persisted blocks.
{Index,Chunk,Tombstone}Readers are more consistent about their Close()
method. Whenever a reader is retrieved, the corresponding close method
must eventually be called. We use this to track pending readers against
persisted blocks.
Querier's against the DB no longer hold a read lock for their entire
lifecycle. This avoids long running queriers to starve new ones when we
have to acquire a write lock when reloading blocks.
