This changes the structure to a single WAL backed by a single head
block.
Parts of the head block can be compacted. This relieves us from any head
amangement and greatly simplifies any consistency and isolation concerns
by just having a single head.
Change index persistence for series to not be accumulated in memory
before being written as one large batch. `Labels` and `ChunkMeta`
objects are reused.
This cuts down memory spikes during compaction of multiple blocks
significantly.
As part of the the Index{Reader,Writer} now have an explicit notion of
symbols and series must be inserted in order.
Implement labels.PrefixMatcher and use interface conversion in querier
to optimize label tuples search.
[unit-tests]: Fix bug and populate label index for mock index.
Signed-off-by: Dmitry Ilyevsky <ilyevsky@gmail.com>
When we have only one chunk that is out of range, then we are returning
it unpopulated (w/o calling `Chunk(ref)`). This would cause a panic
downstream.
Fixes: prometheus/prometheus#2629
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
Mutating the chunks can change their length. Hence referencing using
previous indices can cause panics.
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
Fixes#43
Added mint, maxt to chunkSeriesIterator. Adding a field there is
inevitable as something similar is required for ignoring deleted
time-ranges.
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
This adds a proper duration based lookback buffer for series iterators
to allow advancing sequentially while remaining able to calculate time
aggregating functions such as `rate` backwards.
It uses an array ring buffer to minimize heap allocations for
potentially hundreds of thousands of series for a single query.
