Commit graph

17 commits

Author SHA1 Message Date
beorn7 b02d900e61 Improve chunk and chunkDesc loading.
Also, clean up some things in the code (especially introduction of the
chunkLenWithHeader constant to avoid the same expression all over the place).

Benchmark results:

BEFORE
BenchmarkLoadChunksSequentially     5000            283580 ns/op          152143 B/op        312 allocs/op
BenchmarkLoadChunksRandomly        20000             82936 ns/op           39310 B/op         99 allocs/op
BenchmarkLoadChunkDescs            10000            110833 ns/op           15092 B/op        345 allocs/op

AFTER
BenchmarkLoadChunksSequentially    10000            146785 ns/op          152285 B/op        315 allocs/op
BenchmarkLoadChunksRandomly        20000             67598 ns/op           39438 B/op        103 allocs/op
BenchmarkLoadChunkDescs            20000             99631 ns/op           12636 B/op        192 allocs/op

Note that everything is obviously loaded from the page cache (as the
benchmark runs thousands of times with very small series files). In a
real-world scenario, I expect a larger impact, as the disk operations
will more often actually hit the disk. To load ~50 sequential chunks,
this reduces the iops from 100 seeks and 100 reads to 1 seek and 1
read.
2015-04-13 21:06:04 +02:00
beorn7 5bea942d8e Improve various things around chunk encoding.
A number of mostly minor things:

- Rename chunk type -> chunk encoding.

- After all, do not carry around the chunk encoding to all parts of
  the system, but just have one place where the encoding for new
  chunks is set based on the flag. The new approach has caveats as
  well, but the polution of so many method signatures is worse.

- Use the default chunk encoding for new chunks of existing
  series. (Previously, only new _series_ would get chunks with the
  default encoding.)

- Use an enum for chunk encoding. (But keep the version number for the
  flag, for reasons discussed previously.)

- Add encoding() to the chunk interface (so that a chunk knows its own
  encoding - no need to have that in a different top-level function).

- Got rid of newFollowUpChunk (which would keep the existing encoding
  for all chunks of a time series). Now only use newChunk(), which
  will create a chunk encoding according to the flag.

- Simplified transcodeAndAdd.

- Reordered methods of deltaEncodedChunk and doubleDeltaEncoded chunk
  to match the order in the chunk interface.

- Only transcode if the chunk is not yet half full. If more than half
  full, add a new chunk instead.
2015-03-14 19:03:20 +01:00
beorn7 13fcf1ddbc Implement double-delta encoded chunks. 2015-03-05 20:33:26 +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 fee88a7a77 Remove the remaining races, new and old.
Also, resolve a few other TODOs.

Change-Id: Icb39b5a5e8ca22ebcb48771cd8951c5d9e112691
2014-12-03 18:07:23 +01:00
Bjoern Rabenstein 7d11019aa2 Squash a few trivial TODOs.
- Delete unneeded file view_adapter.go.
- Assessed that we still need the fingerprints in nodes
  (to create iterators).
- Turned numMemChunkDescs into a metric.

Change-Id: I29be963c795a075ec00c095f76bf26405535609d
2014-11-27 18:26:06 +01:00
Bjoern Rabenstein 14bda4180c Changes after pair code review.
Change-Id: Ib72d40f8e9027818cfbbd32a7a7201eebda07455
2014-11-25 17:12:59 +01:00
Bjoern Rabenstein bb42cc2e2d Evict based on memory pressure. Evict recently used chunks last.
Change-Id: Ie6168f0cdb3917bdc63b6fe15585dd70c1e42afe
2014-11-25 17:10:39 +01:00
Bjoern Rabenstein a617269b12 Avoid unnecessary cloning of the head chunk.
Change-Id: I5da774515d5493166a197b5814d0a720628cfaff
2014-11-25 17:09:04 +01:00
Bjoern Rabenstein 74c9b34a5e Improve storage instrumentation even more.
Add gauge for chunks and chunkdescs in memory (backed by a global
variable to be used later not only for instrumentation but also for
memory management).

Refactored instrumentation code once more (instrumentation.go is back :).

Change-Id: Ife39947e22a48cac4982db7369c231947f446e17
2014-11-25 17:09:04 +01:00
Bjoern Rabenstein 443dd33805 Improve instrumentation in storage.
Also, fix some other minor bugs.

Change-Id: If72f1c058b0f47d3e378fdf80228d7e9a8db06c7
2014-11-25 17:09:04 +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 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
Julius Volz 8dfaa5ecd2 Remove use of freelists for chunk bufs.
Change-Id: Ib887fdb61e1d96da0cd32545817b925ba88831c1
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
Julius Volz e7ed39c9a6 Initial experimental snapshot of next-gen storage.
Change-Id: Ifb8709960dbedd1d9f5efd88cdd359ee9fa9d26d
2014-11-25 17:02:00 +01:00