Commit graph

2302 commits

Author SHA1 Message Date
Aliaksandr Valialkin
645365b2d1
lib/promscrape: fix BenchmarkScrapeWorkScrapeInternal, which has been broken by the commit 65bc460323 2024-01-30 16:07:40 +02:00
Aliaksandr Valialkin
61562cdee9
lib/storage: keep (date, metricID) entries only for the last two dates
Entries for the previous dates is usually not used, so there is little sense in keeping them in memory.

This should reduce the size of storage/date_metricID cache, which can be monitored
via vm_cache_entries{type="storage/date_metricID"} metric.
2024-01-29 18:44:27 +01:00
hagen1778
2ff94b2bfa
lib/streamaggr: fix incorrect err message for min interval value
Signed-off-by: hagen1778 <roman@victoriametrics.com>
2024-01-29 17:27:23 +01:00
Aliaksandr Valialkin
f5559c038c
lib/storage: do not check the limit for -search.maxUniqueTimeseries when performing /api/v1/labels and /api/v1/label/.../values requests
This limit has little sense for these APIs, since:

- Thses APIs frequently result in scanning of all the time series on the given time range.
  For example, if extra_filters={datacenter="some_dc"} .

- Users expect these APIs shouldn't hit the -search.maxUniqueTimeseries limit,
  which is intended for limiting resource usage at /api/v1/query and /api/v1/query_range requests.

Also limit the concurrency for /api/v1/labels, /api/v1/label/.../values
and /api/v1/series requests in order to limit the maximum memory usage and CPU usage for these API.
This limit shouldn't affect typical use cases for these APIs:

- Grafana dashboard load when dashboard labels should be loaded
- Auto-suggestion list load when editing the query in Grafana or vmui

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5055
2024-01-29 16:44:46 +01:00
Aliaksandr Valialkin
412f872597
lib/decimal: follow-up for e6bad5174f
- Add a benchmark for CalbirateAndScale.
- Reduce the decimal multipliers table size from 256Kb to 192bytes.
- Use more clear naming for variables.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5672
2024-01-27 00:08:32 +01:00
Fuchun Zhang
e6bad5174f
Optimize the performance of data merge: decimal.CalibrateScale() (#5672)
* Optimize the performance of data merge: decimal.CalibrateScale() from 49633 ns/op to 9146 ns/op

* Optimize the performance of data merge: decimal.CalibrateScale()
2024-01-27 00:05:04 +01:00
Hui Wang
f579adf05f
add inserting comma inside value instruction to flag description (#5666) 2024-01-26 22:47:33 +01:00
Roman Khavronenko
9e9f170fe7
lib/streamaggr: skip unfinished aggregation state on shutdown by default (#5689)
Sending unfinished aggregate states tend to produce unexpected anomalies with lower values than expected.
The old behavior can be restored by specifying `flush_on_shutdown: true` setting in streaming aggregation config

Signed-off-by: hagen1778 <roman@victoriametrics.com>
2024-01-26 22:45:45 +01:00
Aliaksandr Valialkin
7a8b92b590
lib/{mergeset,storage}: make background merge more responsive and scalable
- Maintain a separate worker pool per each part type (in-memory, file, big and small).
  Previously a shared pool was used for merging all the part types.
  A single merge worker could merge parts with mixed types at once. For example,
  it could merge simultaneously an in-memory part plus a big file part.
  Such a merge could take hours for big file part. During the duration of this merge
  the in-memory part was pinned in memory and couldn't be persisted to disk
  under the configured -inmemoryDataFlushInterval .

  Another common issue, which could happen when parts with mixed types are merged,
  is uncontrolled growth of in-memory parts or small parts when all the merge workers
  were busy with merging big files. Such growth could lead to significant performance
  degradataion for queries, since every query needs to check ever growing list of parts.
  This could also slow down the registration of new time series, since VictoriaMetrics
  searches for the internal series_id in the indexdb for every new time series.

  The third issue is graceful shutdown duration, which could be very long when a background
  merge is running on in-memory parts plus big file parts. This merge couldn't be interrupted,
  since it merges in-memory parts.

  A separate pool of merge workers per every part type elegantly resolves both issues:
  - In-memory parts are merged to file-based parts in a timely manner, since the maximum
    size of in-memory parts is limited.
  - Long-running merges for big parts do not block merges for in-memory parts and small parts.
  - Graceful shutdown duration is now limited by the time needed for flushing in-memory parts to files.
    Merging for file parts is instantly canceled on graceful shutdown now.

- Deprecate -smallMergeConcurrency command-line flag, since the new background merge algorithm
  should automatically self-tune according to the number of available CPU cores.

- Deprecate -finalMergeDelay command-line flag, since it wasn't working correctly.
  It is better to run forced merge when needed - https://docs.victoriametrics.com/#forced-merge

- Tune the number of shards for pending rows and items before the data goes to in-memory parts
  and becomes visible for search. This improves the maximum data ingestion rate and the maximum rate
  for registration of new time series. This should reduce the duration of data ingestion slowdown
  in VictoriaMetrics cluster on e.g. re-routing events, when some of vmstorage nodes become temporarily
  unavailable.

- Prevent from possible "sync: WaitGroup misuse" panic on graceful shutdown.

This is a follow-up for fa566c68a6 .
Thanks @misutoth to for the inspiration at https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5212

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5190
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3790
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3551
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3337
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3425
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3647
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3641
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/648
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/291
2024-01-26 22:19:52 +01:00
Aliaksandr Valialkin
c067f3f288
lib/mergeset: remove inmemoryBlock pooling, since it wasn't effecitve
This should reduce memory usage a bit when new time series are ingested at high rate (aka high churn rate)
2024-01-26 21:34:22 +01:00
Aliaksandr Valialkin
230ef43a32
lib/logstorage: make sure that WaitGroup.Add isnt called after stopCh is closed and WaitGroup.Wait is called
This protects from rare panic, which may occur during graceful shutdown of VictoriaLogs
2024-01-26 21:18:07 +01:00
Aliaksandr Valialkin
0715f1efcd
lib/storage: rename *AssistedMerges to *AssistedMergesCount in order to make these field names less misleading
These fields are counters, not gauges, so adding Count suffix to them makes easier to understand this while reading the code
2024-01-25 10:21:13 +02:00
Aliaksandr Valialkin
1cdef56d84
lib/mergeset: start assisted merge for file parts only if the number of file parts is bigger than maxFileParts
The maxFileParts usage has been accidentally removed in fa566c68a6

While at it, add Count suffix to *AssistedMerges counter names in order to make them less misleading.
Previously their names were falsely suggesting that these are gauges, which show the number of concurrently
executed assisted merges.
2024-01-24 15:10:48 +02:00
Aliaksandr Valialkin
b8c7f0d3bc
lib/promscrape/discovery/kubernetes: typo fix in the comment for ContainerStateTerminated struct
This is a follow-up for ef12598ad4
2024-01-24 15:10:47 +02:00
Aliaksandr Valialkin
1e364c992d
lib/promscrape/discovery/kubernetes: do not generate targets for already terminated pods and containers
Already terminated pods and containers cannot be scraped and will never resurrect,
so there is zero sense in creating scrape targets for them.
2024-01-24 14:58:51 +02:00
Aliaksandr Valialkin
e6e5b97e1e
lib/streamaggr: expand %{ENV} placeholders in stream aggregation configs 2024-01-24 12:31:42 +02:00
Aliaksandr Valialkin
12698b9136
lib/mergeset: really limit the number of in-memory parts to 15
It has been appeared that the registration of new time series slows down linearly
with the number of indexdb parts, since VictoriaMetrics needs to check every indexdb part
when it searches for TSID by newly ingested metric name.

The number of in-memory parts grows when new time series are registered
at high rate. The number of in-memory parts grows faster on systems with big number
of CPU cores, because the mergeset maintains per-CPU buffers with newly added entries
for the indexdb, and every such entry is transformed eventually into a separate in-memory part.

The solution has been suggested in https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5212
by @misutoth - to limit the number of in-memory parts with buffered channel.
This solution is implemented in this commit. Additionally, this commit merges per-CPU parts
into a single part before adding it to the list of in-memory parts. This reduces CPU load
when searching for TSID by newly ingested metric name.

The https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5212 recommends setting the limit on the number
of in-memory parts to 100, but my internal testing shows that much lower limit 15 works with the same efficiency
on a system with 16 CPU cores while reducing memory usage for `indexdb/dataBlocks` cache by up to 50%.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5190
2024-01-24 03:41:19 +02:00
Aliaksandr Valialkin
8dd73574ca
lib/encoding: remove uneeded re-slicing of byte slice before passing it to binary.BigEndian.Uint* 2024-01-23 22:50:11 +02:00
Aliaksandr Valialkin
5a97668ad6
lib/handshake: substitute time.Now() with fastttime.UnixTimestamp(), since profiling shows time.Now() is slow 2024-01-23 18:39:28 +02:00
Aliaksandr Valialkin
3199558da9
lib/{storage,mergeset}: reduce the maxium compression level for the stored data
This reduces CPU usage a bit, while doesn't increase resulting file sizes according to synthetic tests.
2024-01-23 17:47:40 +02:00
Aliaksandr Valialkin
68d76b1436
lib/storage: compress metricIDs, which match the given filters, before storing them in tagFiltersToMetricIDsCache
This allows reducing the indexdb/tagFiltersToMetricIDs cache size by 8 on average.
The cache size can be checked via vm_cache_size_bytes{type="indexdb/tagFiltersToMetricIDs"} metric exposed at /metrics page.
2024-01-23 16:13:25 +02:00
Aliaksandr Valialkin
9b3217db61
lib/storage: do not sort metricIDs passed to Storage.prefetchMetricNames, since the caller is responsible for the sorting 2024-01-23 16:13:19 +02:00
Aliaksandr Valialkin
7ed7eb95b4
lib/filestream: do not measure read / write duration from / to in-memory buffers
Measuring read / write duration from / to in-memory buffers has little sense,
since it will be always fast. It is better to measure read / write duration from / to
real files at vm_filestream_write_duration_seconds_total and vm_filestream_read_duration_seconds_total metrics.
This also reduces overhead on time.Now() and Histogram.UpdateDuration() calls
per each filestream.Reader.Read() and filestream.Writer.Write() call when the data is read / written from / to in-memory buffers.

This is a follow-up for 2f63dec2e3
2024-01-23 14:53:35 +02:00
Roman Khavronenko
8461add541
lib/promscrape: respect 0 value for series_limit param (#5663)
* lib/promscrape: respect `0` value for `series_limit` param

Respect `0` value for `series_limit` param in `scrape_config`
even if global limit was set via `-promscrape.seriesLimitPerTarget`.
Previously, `0` value will be ignored in favor of `-promscrape.seriesLimitPerTarget`.

This behavior aligns with possibility to override `series_limit` value via
relabeling with `__series_limit__` label.

Signed-off-by: hagen1778 <roman@victoriametrics.com>

* Update docs/CHANGELOG.md

---------

Signed-off-by: hagen1778 <roman@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2024-01-23 13:09:36 +02:00
Aliaksandr Valialkin
c2927053ee
lib/mergeset: make sure that the first and the last items are in the original range after prepareBlock()
Previously the checks were to strict by requiring to leave the same first and last items by prepareBlock()

Thanks to @ahfuzhang for the suggestion at https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5655
2024-01-23 12:59:04 +02:00
Aliaksandr Valialkin
389159767d
lib/mergeset: skip comparison for every item in the block during merge if the last item in the block is smaller than the first item in the next block
Thanks to @ahfuzhang for the suggestion at https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5651
2024-01-23 03:16:30 +02:00
Zakhar Bessarab
60ef978ffc
lib/storage: print tenant ID in log when discarding or truncating labels (#5658)
Previously, it was not possible to determine which tenant sends metrics with excessive amount of labels of label values.

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2024-01-23 02:27:59 +02:00
Aliaksandr Valialkin
d52fd73f18
all: add up to 10% random jitter to the interval between periodic tasks performed by various components
This should smooth CPU and RAM usage spikes related to these periodic tasks,
by reducing the probability that multiple concurrent periodic tasks are performed at the same time.
2024-01-22 18:39:16 +02:00
Aliaksandr Valialkin
64e615e6cc
lib/storage: reduce the contention on dateMetricIDCache mutex when new time series are registered at high rate
The dateMetricIDCache puts recently registered (date, metricID) entries into mutable cache protected by the mutex.
The dateMetricIDCache.Has() checks for the entry in the mutable cache when it isn't found in the immutable cache.
Access to the mutable cache is protected by the mutex. This means this access is slow on systems with many CPU cores.
The mutabe cache was merged into immutable cache every 10 seconds in order to avoid slow access to mutable cache.
This means that ingestion of new time series to VictoriaMetrics could result in significant slowdown for up to 10 seconds
because of bottleneck at the mutex.

Fix this by merging the mutable cache into immutable cache after len(cacheItems) / 2
cache hits under the mutex, e.g. when the entry is found in the mutable cache.
This should automatically adjust intervals between merges depending on the addition rate
for new time series (aka churn rate):

- The interval will be much smaller than 10 seconds under high churn rate.
  This should reduce the mutex contention for mutable cache.
- The interval will be bigger than 10 seconds under low churn rate.
  This should reduce the uneeded work on merging of mutable cache into immutable cache.
2024-01-22 18:14:30 +02:00
Aliaksandr Valialkin
c6f6f094c5
Revert "lib/promscrape: do not store last scrape response when stale markers … (#5577)"
This reverts commit cfec258803.

Reason for revert: the original code already doesn't store the last scrape response when stale markers are disabled.
The scrapeWork.areIdenticalSeries() function always returns true is stale markers are disabled.
This prevents from storing the last response at scrapeWork.processScrapedData().

It looks like the reverted commit could also return back the issue https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3660

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5577
2024-01-22 01:46:12 +02:00
Aliaksandr Valialkin
d4a1a28543
app/vmselect: handle negative time range start in a generic manner inside NewSearchQuery()
This is a follow-up for cf03e11d89

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5553
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5630
2024-01-22 01:39:27 +02:00
Hui Wang
49fa92c1d0
lib/promscrape/discovery/kubernetes: fix watcher start order for roles endpoints and endpointslice (#5557)
* lib/promscrape/discovery/kubernetes: fix watcher start order for roles endpoints and endpointslice

Previously the groupWatcher could be mistakenly stopped when requests for pod or services resources take too long.

* remove mislead comment

* docs/sd_configs.md: mention -promscrape.kubernetes.attachNodeMetadataAll flag in the description for attach_metadata section

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4640

* wip

* lib/promscrape/kubernetes: prevent from stopping groupWatcher when there are in-flight apiWatcher.mustStart() calls

groupWatcher is stopped if it has zero registered apiWatchers during 14 seconds.
But such a groupWatcher can be still in use if apiWatcher for `role: endpoints` or `role: endpointslice`
is being registered and the discovery of the associated `pod` and/or `service` objects takes longer
than 14 seconds - see the beginning of groupWatcher.startWatchersForRole() function for details.

Track the number of in-flight calls to apiWatcher.mustStart() and prevent from stopping the associated groupWatcher
if the number of in-flight calls is non-zero.

P.S. postponing the discovery of `pod` and/or `service` objects associated with `endpoints` or `endpointslice` roles
isn't the best solution, since it slows down initial discovery of `endpoints` and `endpointslice` targets.

* typo fix

---------

Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2024-01-22 01:33:17 +02:00
Aliaksandr Valialkin
885ee160c2
all: allow dynamically reading *AuthKey flag values from files and urls
Examples:

1) -metricsAuthKey=file:///abs/path/to/file - reads flag value from the given absolute filepath
2) -metricsAuthKey=file://./relative/path/to/file - reads flag value from the given relative filepath
3) -metricsAuthKey=http://some-host/some/path?query_arg=abc - reads flag value from the given url

The flag value is automatically updated when the file contents changes.
2024-01-22 01:23:23 +02:00
Aliaksandr Valialkin
5f5fcab217
all: call atomic.Load* in front of atomic.CompareAndSwap* at places where the atomic.CompareAndSwap* returns false most of the time
This allows avoiding slow inter-CPU synchornization induced by atomic.CompareAndSwap*
2024-01-22 01:13:41 +02:00
Aliaksandr Valialkin
be5faef552
lib/promscrape: code cleanup: send stale markers immediately after generating automatic metrics
This cleanup has been extracted from https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5557/files#diff-6b205cf6637d7b65a5c45d9417d08822d4efad94227268cb196f61aa2a0fc0f7
2024-01-22 01:12:56 +02:00
Aliaksandr Valialkin
e15f07d989
all: consistently clear prompbmarshal.Label by assigning an empty struct instead of zeroing Name and Value individually 2024-01-22 01:11:59 +02:00
Aliaksandr Valialkin
2f94bef59c
lib/storage/partition.go: remove misleading comment, which falsely states that inmemoryParts isn't visible to search
Thanks to @satjd for raising attention to this comment at https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5410
2024-01-22 01:11:36 +02:00
Aliaksandr Valialkin
2c7c812a9d
lib/promscrape/discovery/kubernetes: add -promscrape.kubernetes.attachNodeMetadataAll command-line flag
This flag allows setting attach_metadata.node=true for all the kubernetes_sd_configs defined at -promscrape.config

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4640

Thanks to wasim-nihal for the initial implementation at https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5593
2024-01-22 01:08:52 +02:00
Nikolay
e196c61e36
app/vmselect: abort streaming connections for vmselect (#5650)
* app/vmselect: abort streaming connections for vmselect
due to streaming nature of export APIs, curl and simmilr tools cannot
detect errors that happened after http.Header with status 200 was
written to it.

This PR tracks if body write was already started and closes connection.

It allows client to detect not expected chunk sequence and return error
to the caller.

Mostly it affects vmselect at cluster version

https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5645

* wip

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5645
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5650

---------

Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2024-01-22 00:54:32 +02:00
Aliaksandr Valialkin
c05982bfa7
lib/promscrape/discovery/hetzner: follow-up after 03a97dc678
- docs/sd_configs.md: moved hetzner_sd_configs docs to the correct place according to alphabetical order of SD names,
  document missing __meta_hetzner_role label.
- lib/promscrape/config.go: added missing MustStop() call for Hetzner SD,
  and moved the code to the correct place according to alphabetical order of SD names.
- lib/promscrape/discovery/hetzner: properly handle pagination for hloud API responses,
  populate missing __meta_hetzner_role label like Prometheus does.
- Properly populate __meta_hetzner_public_ipv6_network label like Prometheus does.
- Remove unused SDConfig.Token.
- Remove "omitempty" annotation from SDConfig.Role field, since this field is mandatory.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5550
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3154
2024-01-22 00:53:23 +02:00
Hui Wang
66eb013b54
lib/promscrape: do not store last scrape response when stale markers … (#5577)
* lib/promscrape: do not store last scrape response when stale markers are disabled

* update changelog
2024-01-22 00:52:25 +02:00
Aliaksandr Valialkin
41d6c8a7dd
lib/storage: do not prefetch metric names for small number of metricIDs
This eliminates prefetchedMetricIDsLock lock contention for queries, which return less than 500 time series.

This is a follow-up for 9d886a2eb0
2024-01-17 13:50:01 +02:00
Aliaksandr Valialkin
09f23b0296
lib/promscrape: cosmetic changes after 3ac44baebe
- Rename mustLoadScrapeConfigFiles() to loadScrapeConfigFiles(), since now it may return error.
- Split too long line with the error message into two lines in order to improve readability a bit.

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5508
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5560
2024-01-17 01:07:16 +02:00
Aliaksandr Valialkin
75c58ab306
lib/httputils: handle step=undefined query arg as an empty value
This is needed for Grafana, which may send step=undefined
when working with alerting rules and instant queries.
2024-01-17 00:13:04 +02:00
Aliaksandr Valialkin
f673039e86
lib/storage: follow-up for 4b8088e377
- Clarify the bugfix description at docs/CHANGELOG.md
- Simplify the code by accessing prefetchedMetricIDs struct under the lock
  instead of using lockless access to immutable struct.
  This shouldn't worsen code scalability too much on busy systems with many CPU cores,
  since the code executed under the lock is quite small and fast.
  This allows removing cloning of prefetchedMetricIDs struct every time
  new metric names are pre-fetched. This should reduce load on Go GC,
  since the cloning of uin64set.Set struct allocates many new objects.
2024-01-16 22:38:57 +02:00
Hui Wang
2f40ed3aac
exit vmagent if there is config syntax error in scrape_config_files when -promscrape.config.strictParse=true (#5560) 2024-01-16 22:35:18 +02:00
Aliaksandr Valialkin
6ba2fd3312
app/vmselect/promql: follow-up for ce4f26db02
- Document the bugfix at docs/CHANGELOG.md
- Filter out NaN values before sorting as suggested at https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5509#discussion_r1447369218
- Revert unrelated changes in lib/filestream and lib/fs
- Use simpler test at app/vmselect/promql/exec_test.go

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5509
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5506
2024-01-16 22:13:13 +02:00
Zongyang
cb37df5723
FIX bottomk doesn't return any data when there are no time range overlap between timeseries (#5509)
* FIX sort order in bottomk

* Add lessWithNaNsReversed for bottomk

* Add ut for TopK

* Move lt from loop

* FIX lint

* FIX lint

* FIX lint

* Mod log format

---------

Co-authored-by: xiaozongyang <xiaozngyang@kanyun.com>
Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2024-01-16 22:12:49 +02:00
Aliaksandr Valialkin
724223fad4
lib/prompbmarshal: move WriteRequest proto definition to the correct place 2024-01-16 21:57:03 +02:00
Aliaksandr Valialkin
0196902b2e
lib/promscrape/discovery/hetzner: fix golangci-lint warnings after 03a97dc678
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5550
2024-01-16 21:51:48 +02:00