prometheus

Commit Graph

Author	SHA1	Message	Date
beorn7	d0a4477446	Merge branch 'beorn7/storage3' into beorn7/storage4 Conflicts: storage/local/preload.go storage/local/storage.go storage/local/storage_test.go	9 years ago
beorn7	beb36df4bb	De-flag preloadChunksForRange Now there is preloadChunksForRange and preloadChunksForInstant in both, the series and the storage.	9 years ago
beorn7	0ea5801e47	Handle errors caused by data corruption more gracefully This requires all the panic calls upon unexpected data to be converted into errors returned. This pollute the function signatures quite lot. Well, this is Go... The ideas behind this are the following: - panic only if it's a programming error. Data corruptions happen, and they are not programming errors. - If we detect a data corruption, we "quarantine" the series, essentially removing it from the database and putting its data into a separate directory for forensics. - Failure during writing to a series file is not considered corruption automatically. It will call setDirty, though, so that a crashrecovery upon the next restart will commence and check for that. - Series quarantining and setDirty calls are logged and counted in metrics, but are hidden from the user of the interfaces in interface.go, whith the notable exception of Append(). The reasoning is that we treat corruption by removing the corrupted series, i.e. a query for it will return no results on its next call anyway, so return no results right now. In the case of Append(), we want to tell the user that no data has been appended, though. Minor side effects: - Now consistently using filepath.* instead of path.*. - Introduced structured logging where I touched it. This makes things less consistent, but a complete change to structured logging would be out of scope for this PR.	9 years ago
beorn7	ce58fd357b	Merge branch 'beorn7/storage' into beorn7/storage2 Conflicts: storage/local/chunk.go storage/local/interface.go	9 years ago
beorn7	2581648f70	Separate iterators by offset Add test that exposes the problem.	9 years ago
beorn7	454ecf3f52	Rework the way ranges and instants are handled In a way, our instants were also ranges, just with the staleness delta as range length. They are no treated equally, just that in one case, the range length is set as range, in the other the staleness delta. However, there are "real" instants where start and and time of a query is the same. In those cases, we only want to return a single value (the one closest before or at the equal start and end time). If that value is the last sample in the series, odds are we have it already in the series object. In that case, there is no need to pin or load any chunks. A special singleSampleSeriesIterator is created for that. This should greatly speed up instant queries as they happen frequently for rule evaluations.	9 years ago
beorn7	0e202dacb4	Streamline series iterator creation This will fix issue #1035 and will also help to make issue #1264 less bad. The fundamental problem in the current code: In the preload phase, we quite accurately determine which chunks will be used for the query being executed. However, in the subsequent step of creating series iterators, the created iterators are referencing _all_ in-memory chunks in their series, even the un-pinned ones. In iterator creation, we copy a pointer to each in-memory chunk of a series into the iterator. While this creates a certain amount of allocation churn, the worst thing about it is that copying the chunk pointer out of the chunkDesc requires a mutex acquisition. (Remember that the iterator will also reference un-pinned chunks, so we need to acquire the mutex to protect against concurrent eviction.) The worst case happens if a series doesn't even contain any relevant samples for the query time range. We notice that during preloading but then we will still create a series iterator for it. But even for series that do contain relevant samples, the overhead is quite bad for instant queries that retrieve a single sample from each series, but still go through all the effort of series iterator creation. All of that is particularly bad if a series has many in-memory chunks. This commit addresses the problem from two sides: First, it merges preloading and iterator creation into one step, i.e. the preload call returns an iterator for exactly the preloaded chunks. Second, the required mutex acquisition in chunkDesc has been greatly reduced. That was enabled by a side effect of the first step, which is that the iterator is only referencing pinned chunks, so there is no risk of concurrent eviction anymore, and chunks can be accessed without mutex acquisition. To simplify the code changes for the above, the long-planned change of ValueAtTime to ValueAtOrBefore time was performed at the same time. (It should have been done first, but it kind of accidentally happened while I was in the middle of writing the series iterator changes. Sorry for that.) So far, we actively filtered the up to two values that were returned by ValueAtTime, i.e. we invested work to retrieve up to two values, and then we invested more work to throw one of them away. The SeriesIterator.BoundaryValues method can be removed once #1401 is fixed. But I really didn't want to load even more changes into this PR. Benchmarks: The BenchmarkFuzz.* benchmarks run 83% faster (i.e. about six times faster) and allocate 95% fewer bytes. The reason for that is that the benchmark reads one sample after another from the time series and creates a new series iterator for each sample read. To find out how much these improvements matter in practice, I have mirrored a beefy Prometheus server at SoundCloud that suffers from both issues #1035 and #1264. To reach steady state that would be comparable, the server needs to run for 15d. So far, it has run for 1d. The test server currently has only half as many memory time series and 60% of the memory chunks the main server has. The 90th percentile rule evaluation cycle time is ~11s on the main server and only ~3s on the test server. However, these numbers might get much closer over time. In addition to performance improvements, this commit removes about 150 LOC.	9 years ago
Fabian Reinartz	306e8468a0	Switch from client_golang/model to common/model	9 years ago
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.	10 years ago
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.	10 years ago
Bjoern Rabenstein	674624f1c8	Completed more TODOs. - Documented checkpoint file format. - High-level description of series sanitation. - Replace fp.LoadFromString panic with an error. (Change in client_golang already submitted.) - Introduced checks for series file size where appropriate. - Removed two Law of Demeter violations. Change-Id: I555d97a2c8f4769820c2fc8bf5d6f4e160222abc	10 years ago
Bjoern Rabenstein	bb42cc2e2d	Evict based on memory pressure. Evict recently used chunks last. Change-Id: Ie6168f0cdb3917bdc63b6fe15585dd70c1e42afe	10 years ago
Bjoern Rabenstein	443dd33805	Improve instrumentation in storage. Also, fix some other minor bugs. Change-Id: If72f1c058b0f47d3e378fdf80228d7e9a8db06c7	10 years ago
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	10 years ago
Bjoern Rabenstein	e9ff29c547	Comment/code cleanup. Change-Id: I38736e3d0fec79759a2bafa35aecf914480ff810	10 years ago
Bjoern Rabenstein	71206dbc06	More code cleanups. Add license text everywhere. And others.... Change-Id: I11ccde267a2ef7eb366c4788ba7aeae14ba7545c	10 years ago
Bjoern Rabenstein	f5f9f3514a	Major code cleanup. - Make it go-vet and golint clean. - Add comments, TODOs, etc. Change-Id: If1392d96f3d5b4cdde597b10c8dff1769fcfabe2	10 years ago
Julius Volz	e7ed39c9a6	Initial experimental snapshot of next-gen storage. Change-Id: Ifb8709960dbedd1d9f5efd88cdd359ee9fa9d26d	10 years ago

18 Commits (a2fc87630649c6d3787b829785391e30304d1276)