add command-line flag `-search.inmemoryBufSizeBytes` for configuring size of in-memory buffers used by vmselect during processing of vmstorage responses. A new summary metric `vm_tmp_blocks_inmemory_file_size_bytes` is exposed to show the size of the buffer during requests processing.
The new setting can be used by experienced users to adjust memory usage by vmselect when processing
many small read requests. Instead of allocating 4MB buffers each time, vmselect can be instructed to lower
the buffer size via `-search.inmemoryBufSizeBytes`. To make the decision whether this flag needs to be adjusted
users can consult with `vm_tmp_blocks_inmemory_file_size_bytes` which shows the actual size of buffers used
during query processing.
----------
The detailed information of this PR can be found in
https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6851
### Checklist
The following checks are **mandatory**:
- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Co-authored-by: hagen1778 <roman@victoriametrics.com>
(cherry picked from commit cab3ef8294)
The %q formatter may result in incorrectly formatted JSON string if the original string
contains special chars such as \x1b . They must be encoded as \u001b , otherwise the resulting JSON string
cannot be parsed by JSON parsers.
This is a follow-up for c0caa69939
See https://github.com/VictoriaMetrics/victorialogs-datasource/issues/24
Consistently using t.Fatal* simplifies the test code and makes it less fragile, since it is common error
to forget to make proper cleanup after t.Error* call. Also t.Error* calls do not provide any practical
benefits when some tests fail. They just clutter test output with additional noise information,
which do not help in fixing failing tests most of the time.
While at it, improve errors generated at app/victoria-metrics tests, so they contain more useful information
when debugging failed tests.
This is a follow-up for a9525da8a4
### Describe Your Changes
In most cases histograms are exposed in sorted manner with lower buckets
being first. This means that during scraping buckets with lower bounds
have higher chance of being updated earlier than upper ones.
Previously, values were propagated from upper to lower bounds, which
means that in most cases that would produce results higher than expected
once all buckets will become updated.
Propagating from upper bound effectively limits highest value of
histogram to the value of previous scrape. Once the data will become
consistent in the subsequent evaluation this causes spikes in the
result.
Changing propagation to be from lower to higher buckets reduces value
spikes in most cases due to nature of the original inconsistency.
See: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4580
An example histogram with previous(red) and updated(blue) versions:
This also makes logic of filling nan values with lower buckets values: [1 2 3 nan nan nan] => [1 2 3 3 3 3] obsolete.
Since buckets are now fixed from lower ones to upper this happens in the main loop, so there is no need in a second one.
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Andrii Chubatiuk <andrew.chubatiuk@gmail.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
'any' type is supported starting from Go1.18. Let's consistently use it
instead of 'interface{}' type across the code base, since `any` is easier to read than 'interface{}'.
Use metricsql.IsLikelyInvalid() function for determining whether the given query is likely invalid,
e.g. there is high change the query is incorrectly written, so it will return unexpected results.
The query is invalid most of the time if it passes something other than series selector into rollup function.
For example:
- rate(sum(foo))
- rate(foo + bar)
- rate(foo > bar)
Improtant note: the query is considered valid if it misses the lookbehind window in square brackes inside rollup function,
e.g. rate(foo), since this is very convenient MetricsQL extention to PromQL, and this query returns the expected results
most of the time.
Other unsafe query types can be added in the future into metricsql.IsLikelyInvalid().
TODO: probably, the -search.disableImplicitConversion command-line flag must be set by default in the future releases of VictoriaMetrics.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4338
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6180
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6450
This reverts commit 6e395048d3.
Reason for revert: the previous logic was correct.
The purpose of `-search.maxSamplesPerQuery` command-line flag is to limit the amounts of CPU resources,
which could be taken by a single query - see https://docs.victoriametrics.com/#resource-usage-limits .
VictoriaMetrics processes samples in blocks during querying - it reads the block, then unpacks it,
then filters out samples outside the selected time range. This means that it _spends CPU time_
on reading and unpacking of _all the samples_ in every block on the requested time range,
even if only a single sample per each block matches the given time range.
The previous logic was effectively limiting CPU time a single query could take.
The new logic fails limiting CPU time a single query could take in some pathological cases
when only a small fraction of samples per each requested block fit the requested time range.
This allows performing multiplication DoS-attacks by querying very narrow time ranges over historical blocks,
which tend to be full. For example, if the `-search.maxSamplesPerQuery` equals to a billion,
and the query requests a single sample out of 8K samples per each block, this means that the query
may unpack a billion of such blocks without exceeding the limit, e.g. it may unpack and process 8K*1e9=8e12 samples.
This is not what the resource usage limits were created for originally - see https://docs.victoriametrics.com/#resource-usage-limits
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5851
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6464
Check for ranged vector arguments in aggregate expressions when
`-search.disableImplicitConversion` or `-search.logImplicitConversion`
are enabled.
For example, `sum(up[5m])` will fail to execute if these flags are set.
### Describe Your Changes
Please provide a brief description of the changes you made. Be as
specific as possible to help others understand the purpose and impact of
your modifications.
### Checklist
The following checks are **mandatory**:
- [*] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
---------
Signed-off-by: hagen1778 <roman@victoriametrics.com>
- Fix docs for new functions at app/vmselect/graphite/functions.json
- Properly drain series lists on errors in aggregateSeriesListsGeneric() and aggregateSeriesList()
- Add links to docs for the added functions at docs/CHANGELOG.md
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5809
This reverts commit cb23685681.
Reason for revert: the "fix" may hide programming bugs related to incorrect creation of folders
before their use. This may complicate detecting and fixing such bugs in the future.
There are the following fixes for the issue https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5985 :
- To configure the OS to do not drop data from the system-wide temporary directory (aka /tmp).
- To run VictoriaMetrics with -cacheDataPath command-line flag, which points to the directory,
which cannot be removed automatically by the OS.
The case when the user accidentally deletes the directory with some files created by VictoriaMetrics
shouldn't be considered as expected, so VictoriaMetrics shouldn't try resolving this case automatically.
It is much better from operation and debuggability PoV is to crash with the clear `directory doesn't exist` error
in this case.
* lib/storage: add ability to use downsampling for the given series filter
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* docs: add information about downsampling filters
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* docs: fix MetricsQL filter
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/storage/downsampling: treat missing downsampling filter as a bug
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/storage/part_header: verify correctness of downsampling filters when opening partition
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/storage/downsampling: save only appliable rules in part metadata
Filter and save only rules which are appliable to partition based on MinTimestamp of stored data.
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/storage/downsampling: update log messages for final dedup
Properly specify a reason of re-running deduplication for partition.
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* lib/storage: consistently use MaxTimestamp to determine deduplication/downsampling rules
Using MinTimestamp leads to applying downsampling to parts which are only partially covered by downsampling rule.
For example, partition covers range [1000-2000]. At t=2100 and rule offset 500 data with t=2100-500 => 1600 must be downsampled. The range check against MinTimestamp evaluates to true even though partition contains range which must not be downsampled - [1600:2000].
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
* Follow-up
- Apply the first matching downsampling period if multiple filters match the given time series.
This allows fine-tuning the downsampling config for the specific needs.
- Take into account downsampling filters during search queries.
- Reduce the difference between community and enterprise branches. This should simplify further maintenance of these branches.
- Properly parse series filters with colons inside them.
- Document the feature at docs/CHANGELOG.md.
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4960
---------
Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
vmselect uses a cache folder in file system for two purposes:
1. Storing rollup cache results on shutdown;
2. Storing temporary search results from vmstorage during query executions.
It could happen that cache folder is deleted accidentally by user, or by OS
during cleanup routines. This would cause vmselect to:
1. panic on /metrics call, because `MustGetFreeSpace` will fail;
2. return query error user, as it won't be able to store temporary search results.
The changes in this commit are the following:
1. Make `MustGetFreeSpace` to try re-creating the cache folder if it is missing;
2. Make vmselect to try re-creating the cache folder if it can't persist tmp search
results.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5985
Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Nikolay <nik@victoriametrics.com>
The `match[]` filter is mandatory at /api/v1/series, so it mustn't be dropped here.
There is no sense in dropping `match[]` filter together with `extra_label` and `extra_filters[]`
at /api/v1/labels and /api/v1/label/.../values if -search.ignoreExtraFiltersAtLabelsAPI commnad-line flag is set,
since:
- the `match[]` filter triggers slow path at these APIs;
- the `extra_label` and `extra_filters[]` filters narrow down the number of matched time series,
so they improve performance comparing to the case when only `match[]` filter is left,
while `extra_label` and `extra_filters[]` filters are dropped.
This is a follow-up for 0b7a23a91d
The match[] at /api/v1/labels and /api/v1/label/.../values also may lead to slow requests and
high resource usage if it matches big number of time series. So it must be igrnored if -search.ignoreExtraFiltersAtLabelsAPI
command-line flag is set.
This is a follow-up for fab02faa3f
