Commit graph

6 commits

Author SHA1 Message Date
Ganesh Vernekar 328a74ca36
Fix bugs and add enhancements to the chunk snapshot (#9185)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-08-17 18:08:16 +01:00
Bryan Boreham 040ef175eb
Optimise WAL loading by removing extra map and caching min-time (#9160)
* BenchmarkLoadWAL: close WAL after use

So that goroutines are stopped and resources released

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* BenchmarkLoadWAL: make series IDs co-prime with #workers

Series are distributed across workers by taking the modulus of the
ID with the number of workers, so multiples of 100 are a poor choice.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* BenchmarkLoadWAL: simulate mmapped chunks

Real Prometheus cuts chunks every 120 samples, then skips those samples
when re-reading the WAL. Simulate this by creating a single mapped chunk
for each series, since the max time is all the reader looks at.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Fix comment

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Remove series map from processWALSamples()

The locks that is commented to reduce contention in are now sharded
32,000 ways, so won't be contended. Removing the map saves memory and
goes just as fast.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* loadWAL: Cache the last mmapped chunk time

So we can skip calling append() for samples it will reject.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Improvements from code review

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Full stops and capitals on comments

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Cache max time in both places mmappedChunks is updated

Including refactor to extract function `setMMappedChunks`, to reduce
code duplication.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Update head min/max time when mmapped chunks added

This ensures we have the correct values if no WAL samples are added for
that series.

Note that `mSeries.maxTime()` was always `math.MinInt64` before, since
that function doesn't consider mmapped chunks.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-08-10 14:53:31 +05:30
Bryan Boreham 7407457243
Avoid deadlock when processing duplicate series record (#9170)
* Avoid deadlock when processing duplicate series record

`processWALSamples()` needs to be able to send on its output channel
before it can read the input channel, so reads to allow this in case the
output channel is full.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* processWALSamples: update comment

Previous text seems to relate to an earlier implementation.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2021-08-10 13:32:42 +05:30
Ganesh Vernekar ee7e0071d1
Snapshot in-memory chunks on shutdown for faster restarts (#7229)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-08-06 17:51:01 +01:00
Ganesh Vernekar 848cb5a6d6
Enhanced WAL replay for duplicate series record (#7438)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-08-03 20:03:54 +05:30
Ganesh Vernekar 8002a3ab80
Breakdown tsdb/head.go into multiple files (#9147)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-08-03 14:14:26 +02:00