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32 commits

Author SHA1 Message Date
beorn7 434ab2a6a3 storage: Evict chunks and calculate persistence pressure based on target heap size
This is a fairly easy attempt to dynamically evict chunks based on the
heap size. A target heap size has to be set as a command line flage,
so that users can essentially say "utilize 4GiB of RAM, and please
don't OOM".

The -storage.local.max-chunks-to-persist and
-storage.local.memory-chunks flags are deprecated by this
change. Backwards compatibility is provided by ignoring
-storage.local.max-chunks-to-persist and use
-storage.local.memory-chunks to set the new
-storage.local.target-heap-size to a reasonable (and conservative)
value (both with a warning).

This also makes the metrics intstrumentation more consistent (in
naming and implementation) and cleans up a few quirks in the tests.

Answers to anticipated comments:

There is a chance that Go 1.9 will allow programs better control over
the Go memory management. I don't expect those changes to be in
contradiction with the approach here, but I do expect them to
complement them and allow them to be more precise and controlled. In
any case, once those Go changes are available, this code has to be
revisted.

One might be tempted to let the user specify an estimated value for
the RSS usage, and then internall set a target heap size of a certain
fraction of that. (In my experience, 2/3 is a fairly safe bet.)
However, investigations have shown that RSS size and its relation to
the heap size is really really complicated. It depends on so many
factors that I wouldn't even start listing them in a commit
description. It depends on many circumstances and not at least on the
risk trade-off of each individual user between RAM utilization and
probability of OOMing during a RAM usage peak. To not add even more to
the confusion, we need to stick to the well-defined number we also use
in the targeting here, the sum of the sizes of heap objects.
2017-03-27 14:33:50 +02:00
beorn7 96a303b348 storage: Use staleness delta as head chunk timeout
Currently, if a series stops to exist, its head chunk will be kept
open for an hour. That prevents it from being persisted. Which
prevents it from being evicted. Which prevents the series from being
archived.

Most of the time, once no sample has been added to a series within the
staleness limit, we can be pretty confident that this series will not
receive samples anymore. The whole chain as described above can be
started after 5m instead of 1h. In the relaxed case, this doesn't
change a lot as the head chunk timeout is only checked during series
maintenance, and usually, a series is only maintained every six
hours. However, there is the typical scenario where a large service is
deployed, the deoply turns out to be bad, and then it is deployed
again within minutes, and quite quickly the number of time series has
tripled. That's the point where the Prometheus server is stressed and
switches (rightfully) into rushed mode. In that mode, time series are
processed as quickly as possible, but all of that is in vein if all of
those recently ended time series cannot be persisted yet for another
hour. In that scenario, this change will help most, and it's exactly
the scenario where help is most desperately needed.
2017-03-26 23:44:50 +02:00
Björn Rabenstein 1e2f03f668 Merge pull request #2005 from redbaron/microoptimise-matching
Microoptimise matching
2016-10-05 17:26:56 +02:00
Maxim Ivanov e6db9f8159 New fpsForLabelMatchers and seriesForLabelMatchers methods
These more specific methods have replaced `metricForLabelMatchers`
in cases where its  `map[fingerprint]metric` result type was
not necessary or was used as an intermediate step

Avoids duplicated calls to `seriesForRange` from
`QueryRange` and `QueryInstant` methods.
2016-10-05 15:15:54 +01:00
Julius Volz ab80ced756 storage: separate chunk package, publish more names
This is a followup to https://github.com/prometheus/prometheus/pull/2011.

This publishes more of the methods and other names of the chunk code and
moves the chunk code to its own package. There's some unavoidable
ugliness: the chunk and chunkDesc metrics are used by both packages, so
I had to move them to the chunk package. That isn't great, but I don't
see how to do it better without a larger redesign of everything. Same
for the evict requests and some other types.
2016-09-26 13:25:11 +02:00
Matthew Campbell 67d76e3a5d timeseries: store varbit encoded data into cassandra 2016-09-21 17:56:55 +02:00
Julius Volz 91401794fa storage: Make MemorySeriesStorage a public type
See https://twitter.com/fabxc/status/748032597876482048
2016-06-29 08:14:23 +02:00
Julius Volz b7b6717438 Separate query interface out of local.Storage.
PromQL only requires a much narrower interface than local.Storage in
order to run queries. Narrower interfaces are easier to replace and
test, too.

We could also change the web interface to use local.Querier, except that
we'll probably use appending functions from there in the future.
2016-06-23 15:14:38 +02:00
beorn7 e8c1f30ab2 Merge the parallel logic of getSeriesForRange and metricForFingerprint 2016-03-09 21:56:15 +01:00
Julius Volz af513468eb Fix some dead code, missing error checks, shadowings.
I applied
https://medium.com/@jgautheron/quality-pipeline-for-go-projects-497e34d6567
and was greeted with a deluge of warnings, most of which were not
applicable or really fixable realistically. These are some of the first
ones I decided to fix.
2015-09-14 12:21:34 +02:00
Fabian Reinartz b105e26f4d storage: remove global flags 2015-06-15 19:01:06 +02:00
Fabian Reinartz 0de6edbdfc Move pkg/ to util/ 2015-06-01 21:12:32 +02:00
Fabian Reinartz 3c8fbf1e15 Move test package to pkg/testutil 2015-06-01 21:12:31 +02:00
Fabian Reinartz d8440d75f1 Do not start storage processing before Start() is called. 2015-05-19 13:51:45 +02:00
beorn7 2235cec175 Handle fingerprint collisions. 2015-05-07 18:17:59 +02:00
beorn7 12ae6e9203 Increase resilience of the storage against data corruption - step 4.
Step 4: Add a configurable sync'ing of series files after modification.
2015-03-19 15:58:02 +01:00
beorn7 da7c0461c6 Rename persist queue len/cap to num/max chunks to persist.
Remove deprecated flag storage.incoming-samples-queue-capacity.
2015-03-18 19:36:41 +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 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 49683c0c20 Avoid test flags in normal binary.
Change-Id: If1fba813a73bf93ea5918dcda326e3ffa81a797d
2014-11-27 18:04:48 +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 3f61d304ce Reorganize maintenance loop.
Change-Id: Iac10f988ba3e93ffb188f49c30f92e0b6adce5a3
2014-11-25 17:10:30 +01:00
Bjoern Rabenstein f1de5b0c4e Run checkpointing of in-memory metrics and head chunks periodically.
Checkpointing interval is now a command line flag.

Along the way, several things were refactored.
- Restructure the way the storage is started and stopped..
- Number of series in checkpoint is now a uint64, not a varint.
  (Breaks old checkpoints, needs wipe!)
- More consistent naming and order of methods.

Change-Id: I883d9170c9a608ee716bb0ab3d0ded8ca03760d9
2014-11-25 17:09:04 +01:00
Bjoern Rabenstein b3ed9aa7a2 Clean up start-up and shut-down.
Change-Id: Idff4bbb0a15a9f879bfbb3da5b1025179cab5e2c
2014-11-25 17:08:45 +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 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 3b25867d61 Add chunk persistence tests, fix storage tests.
Change-Id: Id0b8f5382e99efa839cc0f826e92bbda985fe9a9
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