Commit graph

22 commits

Author SHA1 Message Date
beorn7 a8d4f8af9a Improve minor things after review.
The problem of float precision will be addressed in the next commit.
2015-03-06 12:53:00 +01:00
beorn7 13fcf1ddbc Implement double-delta encoded chunks. 2015-03-05 20:33:26 +01:00
beorn7 edd716e63c Fix the embarrassing bug introduced in commit 0851945.
In that commit, the 'maintainSeries' call was accidentally removed.

This commit refactors things a bit so that there is now a clean
'maintainMemorySeries' and a 'maintainArchivedSeries' call.

Straighten the nomenclature a bit (consistently use 'drop' for
chunks and 'purge' for series/metrics).

Remove the annoying 'Completed maintenance sweep through archived
fingerprints' message if there were no archived fingerprints to do
maintenance on.
2015-02-26 18:30:33 +01:00
beorn7 af91fb8e31 Improve persisting chunks to disk.
This is done by bucketing chunks by fingerprint. If the persisting to
disk falls behind, more and more chunks are in the queue. As soon as
there are "double hits", we will now persist both chunks in one go,
doubling the disk throughput (assuming it is limited by disk
seeks). Should even more pile up so that we end wit "triple hits", we
will persist those first, and so on.

Even if we have millions of time series, this will still help,
assuming not all of them are growing with the same speed. Series that
get many samples and/or are not very compressable will accumulate
chunks faster, and they will soon get double- or triple-writes.

To improve the chance of double writes,
-storage.local.persistence-queue-capacity could be set to a higher
value. However, that will slow down shutdown a lot (as the queue has
to be worked through). So we leave it to the user to set it to a
really high value. A more fundamental solution would be to checkpoint
not only head chunks, but also chunks still in the persist queue. That
would be quite complicated for a rather limited use-case (running many
time series with high ingestion rate on slow spinning disks).
2015-02-17 16:02:09 +01:00
Bjoern Rabenstein 5859b74f1b Clean up license issues.
- Move CONTRIBUTORS.md to the more common AUTHORS.
- Added the required NOTICE file.
- Changed "Prometheus Team" to "The Prometheus Authors".
- Reverted the erroneous changes to the Apache License.
2015-01-21 20:07:45 +01:00
Bjoern Rabenstein 7af42eda65 Optimize purging.
Now only purge if there is something to purge.
Also, set savedFirstTime and archived time range appropriately.
(Which is needed for the optimization.)

Change-Id: Idcd33319a84def3ce0318d886f10c6800369e7f9
2014-11-25 17:10:30 +01:00
Bjoern Rabenstein 904acd43da Add crash recovery.
Fix the behavior if preload for non-existent series is requested.

Instead of returning an error (which triggers a panic further up),
simply count those incidents. They can happen regularly, we just want
to know if they happen too frequently because that would mean the
indexing is behind or broken.

Change-Id: I4b2d1b93c4146eeea897d188063cb9574a270f8b
2014-11-25 17:09:43 +01:00
Bjoern Rabenstein 5f8e9617ef Add more tests.
Add an end-to-end fuzz and race test.

Fix a race exposed by the above.

Change-Id: Ifaa39a90cefbde8d4c29bda197cc92592ded21bb
2014-11-25 17:09:17 +01:00
Bjoern Rabenstein d215e013b7 Fix the weird chunkDesc shuffling bug.
The root cause was that after chunkDesc eviction, the offset between
memory representation of chunk layout (via chunkDescs in memory) was
shiftet against chunks as layed out on disk. Keeping the offset up to
date is by no means trivial, so this commit is pretty involved.

Also, found a race that for some reason didn't bite us so far:
Persisting chunks was completel unlocked, so if chunks were purged on
disk at the same time, disaster would strike. However, locking the
persisting of chunk revealed interesting dead locks. Basically, never
queue under the fp lock.

Change-Id: I1ea9e4e71024cabbc1f9601b28e74db0c5c55db8
2014-11-25 17:09:17 +01:00
Bjoern Rabenstein 096fa0f8b2 Squash a number of TODOs.
- Staleness delta is no a proper function parameter and not replicated
  from package ast.

- Named type 'chunks' replaced by explicit '[]chunk' to avoid confusion.

- For the same reason, replaced 'chunkDescs' by '[]*chunkDescs'.

- Verified that math.Modf is not a speed enhancement over conversion
  (actually 5x slower).

- Renamed firstTimeField, lastTimeField into chunkFirstTime and
  chunkLastTime.

- Verified unpin() is sufficiently goroutine-safe.

- Decided not to update archivedFingerprintToTimeRange upon series
  truncation and added a rationale why.

Change-Id: I863b8d785e5ad9f71eb63e229845eacf1bed8534
2014-11-25 17:09:04 +01:00
Bjoern Rabenstein 8fba3302bc Bold changes to concurrency.
(WIP. Probably doesn't work yet.)

Change-Id: Id1537dfcca53831a1d428078a5863ece7bdf4875
2014-11-25 17:07:45 +01:00
Bjoern Rabenstein 0031a448e2 Add WaitForIndexing.
Change-Id: I5a5c975c4246632f937413322c855bbe63d00802
2014-11-25 17:07:44 +01:00
Bjoern Rabenstein c7aad110fb Add an indexing queue and batch the ops.
Some other improvements on the way, in particular codec -> codable
renaming and addition of LookupSet methods.

Change-Id: I978f8f3f84ca8e4d39a9d9f152ae0ad274bbf4e2
2014-11-25 17:07:44 +01:00
Bjoern Rabenstein 71206dbc06 More code cleanups.
Add license text everywhere.
And others....

Change-Id: I11ccde267a2ef7eb366c4788ba7aeae14ba7545c
2014-11-25 17:07:44 +01:00
Bjoern Rabenstein f5f9f3514a Major code cleanup.
- Make it go-vet and golint clean.
- Add comments, TODOs, etc.

Change-Id: If1392d96f3d5b4cdde597b10c8dff1769fcfabe2
2014-11-25 17:02:53 +01:00
Bjoern Rabenstein bbf49200ab Implement methods in persistence.go.
Change-Id: I804cdd0b30420e171825fd86fe1281eca0d5e638
2014-11-25 17:02:23 +01:00
Julius Volz 7e85711df0 Beginnings of a tiered index implementation.
This reintroduces a LevelDB-based metrics index.

Change-Id: I4111540301c52255a07b2f570761707a32f72c05
2014-11-25 17:02:00 +01:00
Bjoern Rabenstein d742edfe0d Fix precision loss.
Large delta values often imply a difference between a large base value
and the large delta value, potentially resulting in small numbers with
a huge precision error. Since large delta values need 8 bytes anyway,
we are not even saving memory.

As a solution, always save the absoluto value rather than a delta once
8 bytes would be needed for the delta. Timestamps are then saved as 8
byte integers, while values are always saved as float64 in that case.

Change-Id: I01100d600515e16df58ce508b50982ffd762cc49
2014-11-25 17:02:00 +01:00
Bjoern Rabenstein 52c9dc43a3 Improve testing.
In particular, create a fuzz test for time series.

Change-Id: I523a17912405a0b6b46bd395c781d201dfe55036
2014-11-25 17:02:00 +01:00
Julius Volz 3b25867d61 Add chunk persistence tests, fix storage tests.
Change-Id: Id0b8f5382e99efa839cc0f826e92bbda985fe9a9
2014-11-25 17:02:00 +01:00
Bjoern Rabenstein ecdf5ab14f Index-persistence switched from gob to a hand-coded solution.
Change-Id: Ib4ec42535bd08df16d34d4774bb638e35c5a1841
2014-11-25 17:02:00 +01:00
Julius Volz e7ed39c9a6 Initial experimental snapshot of next-gen storage.
Change-Id: Ifb8709960dbedd1d9f5efd88cdd359ee9fa9d26d
2014-11-25 17:02:00 +01:00