Commit graph

16 commits

Author SHA1 Message Date
Björn Rabenstein c44e7cd105 Merge pull request #706 from prometheus/beorn7/persistence2
Improve iterator performance.
2015-05-21 13:48:52 +02:00
beorn7 3b9c421a69 Weed out all the [Gg]et* method names.
The only exception is getNumChunksToPersist to avoid naming the struct
member numChunksToPersist in a weird way.
2015-05-20 19:13:06 +02:00
Julius Volz 267fd34156 Switch Prometheus to use github.com/prometheus/log.
This change is conceptually very simple, although the diff is large. It
switches logging from "github.com/golang/glog" to
"github.com/prometheus/log", while not actually changing any log
messages. V(1)-style logging has been changed to be log.Debug*().
2015-05-20 18:19:32 +02:00
beorn7 c36e0e05f1 Add crash recovery of fingerprint mappings. 2015-05-07 18:58:14 +02:00
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 c5fa0b90c3 Fix the case where a series in memory has 0 chunks, but chunks on disk.
This is actually completely normal for a freshly unarchived series.

Test added to expose.
2015-04-09 15:57:11 +02:00
beorn7 11bd9ce1bd Increase resilience of the storage against data corruption - step 3.
Step 3: Remember the mtime of series files and make use of it to
detect series files that are not the one the checkpoint thinks they
are.
2015-03-19 15:44:11 +01:00
beorn7 e25cca823c Increase resilience of the storage against data corruption - step 2.
Step 2: Add a flag -storage.local.pedantic-checks to check every
series file.

Also, remove countPersistedHeadChunks channel, which is unused.
2015-03-19 12:06:15 +01:00
beorn7 1d8fc7d56f Change minor things after code review. 2015-03-18 19:09:07 +01:00
beorn7 0056eaeb4f Redesign series maintenance and chunk persistence. 2015-03-14 22:05:23 +01:00
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
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 5d3cd65a5d Improve performance of ingestion.
- Parallelize AppendSamples as much as possible without breaking the
  contract about temporal order.

- Allocate more fingerprint locker slots.

- Do not run early checkpoints if we are behind on chunk persistence.

- Increase fpMinWaitDuration to give the disk more time for more
  important things.

Also, switch math.MaxInt64 and math.MinInt64 to the new constants.
2015-02-12 18:12:37 +01:00
Bjoern Rabenstein 3948e2a7f8 Move lost files to an "orphaned" directory.
Previously, those were simply deleted. The orphaned files can now be
used for forensics if needed.
2015-01-29 14:52:12 +01:00
Bjoern Rabenstein c24bfdf701 Move crash related code into separate file.
persistence.go is way too long anyway, and a lot of code is just crash
recovery, which is not important to understand the normal operation.

Also, remove unused `exists` function.
2015-01-29 13:13:16 +01:00