tstats

Description

Use the tstats command to perform statistical queries on indexed fields in tsidx files. The indexed fields can be from indexed data or accelerated data models.

Because it searches on index-time fields instead of raw events, the tstats command is faster than the stats command.

By default, the tstats command runs over accelerated and unaccelerated data models.

Syntax

The required syntax is in bold.

| tstats

[prestats=<bool>]

[local=<bool>]

[append=<bool>]

[summariesonly=<bool>]

[include_reduced_buckets=<bool>]

[allow_old_summaries=<bool>]

[chunk_size=<unsigned int>]

[fillnull_value=<string>]

<stats-func>...

[FROM ( <namespace> | sid=<tscollect-job-id> | datamodel=<data_model_name>.<root_dataset_name> [where nodename = <root_dataset_name>.<...>.<target_dataset_name>)]]

[WHERE <search-query> | <field> IN (<value-list>)]

[BY (<field-list> | (PREFIX(<field>))) [span=<timespan>] ]

Required arguments

<stats-func>

Syntax: (count [<field>] | <function>(PREFIX(<string>) | <field>))... [AS <string>]

Description: Either perform a basic count of a field or perform a function on a field. For a list of the supported functions for the tstats command, refer to the table below. You must specify one or more functions. You can apply the function to a field, or to a PREFIX() directive if you want to aggregate a raw segment in your indexed events as if it were an extracted field-value pair. You can also rename the result using the AS keyword, unless you are in prestats mode (prestats=true).

You cannot specify functions without applying them to fields or eval expressions that resolve into fields. You cannot use wildcards to specify field names.

See Usage to learn more about using PREFIX(), and about searches you can run to find raw segments in your data.

The following table lists the supported functions by type of function. Use the links in the table to see descriptions and examples for each function. For an overview about using functions with commands, see Statistical and charting functions.

Type of function	Supported functions and syntax
Aggregate functions	avg() count() distinct_count() estdc()	exactperc<int>() max() median() min() mode()	perc<int>() range() stdev() stdevp()	sum() sumsq() upperperc<int>() var() varp()
Event order functions	first()	last()
Multivalue stats and chart functions	values()
Time functions	earliest() earliest_time()	latest() latest_time()	rate()

Optional arguments

append

Syntax: append=<bool>

Description: When in prestats mode (prestats=true), enables append=true where the prestats results append to existing results, instead of generating them.

Default: false

allow_old_summaries

Syntax: allow_old_summaries=true | false

Description: Only applies when selecting from an accelerated data model. When you change the constraints that define a data model but the Splunk software has not fully updated the summaries to reflect that change, the summaries may have some data that matches the old definition and some data that matches the new definition. To return results from summary directories only when those directories are up-to-date, set this parameter to false. If the data model definition has changed, summary directories that are older than the new definition are not used when producing output from the tstats command. This default ensures that the output from tstats always reflects your current configuration.

When set to true, the tstats command uses both current summary data and summary data that was generated prior to the definition change. This is an advanced performance feature for cases where you know that the old summaries are "good enough," meaning the old summary data is close enough to the new summary data that its results are reliable. See When the data model definition changes and your summaries have not been updated to match it in the Splunk Cloud Platform Knowledge Manager Manual.

Default: false

The default value is controlled by the allow_old_summaries setting in the [tstats] stanza in the limits.conf file. If you use Splunk Cloud Platform, file a Support ticket to change this setting.

chunk_size

Syntax: chunk_size=<unsigned_int>

Description: Advanced option. This argument controls how many events are retrieved at a time from a single tsidx file when the Splunk software processes searches. Lower this setting from its default only when you find a particular tstats search is using too much memory, or when it infrequently returns events. This can happen when a search groups by excessively high-cardinality fields (fields with very large amounts of distinct values). In such situations, a lower chunk_size value can make tstats searches more responsive, but potentially slower to complete. A higher chunk_size, on the other hand, can help long-running searches to complete faster, with the potential tradeoff of causing the search to be less responsive. For tstats, chunk_size cannot be set lower than 10000.

Default: 10000000 (10 million)

The default value is controlled by the chunk_size setting in the [tstats] stanza in the limits.conf file. If you use Splunk Cloud Platform, file a Support ticket to change this setting.

fillnull_value

Description: This argument sets a user-specified value that the tstats command substitutes for null values for any field within its group-by field list. Null values include field values that are missing from a subset of the returned events as well as field values that are missing from all of the returned events. If you do not provide a fillnull_value argument, tstats omits rows for events with one or more null field values from its results.

Default: empty string

include_reduced_buckets

Syntax: include_reduced_buckets=true | false

Description: This setting only applies when enableTSIDXReduction=true in indexes.conf. When set to false, the tstats command generates results only from index buckets that are not reduced. Set to true if you want tstats to use results from reduced buckets.

Default: false

local

Syntax: local=true | false

Description: If true, forces the processor to be run only on the search head.

Default: false

prestats

Syntax: prestats=true | false

Description: Specifies whether to use the prestats format. The prestats format is a Splunk internal format that is designed to be consumed by commands that generate aggregate calculations. When using the prestats format you can pipe the data into the chart, stats, or timechart commands, which are designed to accept the prestats format. When prestats=true, AS instructions are not relevant. The field names for the aggregates are determined by the command that consumes the prestats format and produces the aggregate output.

Default: false

summariesonly

Syntax: summariesonly=<bool>

Description: When summariesonly is set to false, if the time range of the tstats search exceeds the summarization range for the selected data model, the tstats command returns results for the entire time range of the search. It quickly returns results from the summarized data, and returns results more slowly from the raw, unsummarized data that exists outside of the data model summary range.

If an accelerated data model is running behind in its summarization, or if its summarization searches are scheduled infrequently, setting summariesonly = false might result in a slower tstats search. This is because the data model has more unsummarized data to search through than usual.

When summariesonly is set to true, the tstats search returns results only from summarized data, even when the time range of the search exceeds the summarization range of the data model. This means the search runs fast, but no unsummarized data is included in the search results. If you set summariesonly to true, the tstats command won't run over unaccelerated data models. Also, when the tstats command runs over accelerated data models, it returns events only from the data model's acceleration summary.

You might set summariesonly = true if you need to identify the data that is currently summarized in a given data model, or if you value search efficiency over completeness of results. See Using the summariesonly argument in the Splunk Cloud Platform Knowledge Manager Manual.

Default: false

The default value is controlled by the summariesonly setting in the [tstats] stanza in the limits.conf file. If you use Splunk Cloud Platform, file a Support ticket to change this setting.

FROM clause arguments

The FROM clause is optional. You can specify either a namespace, an sid, or a datamodel. See Selecting data for more information about this clause.

namespace

Syntax: <string>

Description: Define a location for the tsidx file with $SPLUNK_DB/tsidxstats. If you have Splunk Enterprise, you can configure this location by editing the local version of the indexes.conf file and setting the tsidxStatsHomePath attribute. See How to edit a configuration file in the Admin manual.

sid

Syntax: sid=<tscollect-job-id>

Description: The job ID string of a tscollect search (that generated tsidx files).

datamodel

Syntax: datamodel=<data_model_name>.<root_dataset_name> [where nodename = <root_dataset_name>.<...>.<target_dataset_name>]

Description: The name of a data model, concatenated with the name of the root dataset that you are searching. If you wish to filter on a child dataset, you need to use a where clause that uses nodename to reference a specific child dataset in a dataset hierarchy in the data model. See See Selecting data for more information.

WHERE clause arguments

The optional WHERE clause is used as a filter. You can specify either a search or a field and a set of values with the IN operator.

<search-query>

Specify the search criteria to filter on.

<field> IN (<value-list>)

For the field, specify a list of values to include in the search results.

WHERE clauses in tstat searches must contain field-value pairs that are indexed, as well as characters that are not major breakers or minor breakers. For example, consider the following search:

| tstats count WHERE index=_internal sourcetype=splunkd* by sourcetype

The results look something like this:

sourcetype	count
splunkd	2602154
splunkd_access	319019
splunkd_conf	19

This search returns valid results because sourcetype=splunkd* is an indexed field-value pair and wildcard characters are accepted in the search criteria. The asterisk at the end of the sourcetype=splunkd* clause is treated as a wildcard, and is not regarded as either a major or minor breaker.

BY clause arguments

The BY clause is optional. You cannot use wildcards in the BY clause with the tstats command. See Usage. If you use the BY clause, you must specify a field-list. You can also specify a span.

<field-list>

Syntax: <field>, ...

Description: Specify one or more fields to group results.

PREFIX()

Syntax: PREFIX(<string>)

Description: Specify a raw segment in your indexed events that you want to split by as if it were an extracted field-value pair. See Usage for more information about the PREFIX() directive, and for a search you can run to find raw segments in your indexed data.

span

Syntax: span=<timespan>

Description: The span of each time bin. If you use the BY clause to group by _time, use the span argument to group the time buckets. You can specify timespans such as BY _time span=1h or BY _time span=5d. If you do not specify a <timespan>, the default is auto, which means that the number of time buckets adjusts to produce a reasonable number of results. For example if initially seconds are used for the <timespan> and too many results are being returned, the <timespan> is changed to a longer value, such as minutes, to return fewer time buckets.

Default: auto

<timespan>

Syntax: auto | <int><timescale>

<timescale>

Syntax: <sec> | <min> | <hr> | <day> | <month>

Description: Time scale units. For the tstats command, the <timescale> does not support subseconds.

Default: sec

Time scale	Syntax	Description
<sec>	s | sec | secs | second | seconds	Time scale in seconds.
<min>	m | min | mins | minute | minutes	Time scale in minutes.
<hr>	h | hr | hrs | hour | hours	Time scale in hours.
<day>	d | day | days	Time scale in days.
<month>	mon | month | months	Time scale in months.

Usage

The tstats command is a report-generating command, except when prestats=true. When prestats=true, the tstats command is an event-generating command. See Command types.

Generating commands use a leading pipe character and should be the first command in a search, except when prestats=true.

When you use a statistical function with the tstats command, you can't use an eval expression as part of the statistical function. See Complex aggregate functions.

Selecting data

Use the tstats command to perform statistical queries on indexed fields in tsidx files. You can select the data for the indexed fields in several ways.

Normal index data

Use a FROM clause to specify a namespace, search job ID, or data model. If you do not specify a FROM clause, the Splunk software selects from index data in the same way as the search command. You are restricted to selecting data from your allowed indexes by user role. You control exactly which indexes you select data from by using the WHERE clause. If no indexes are mentioned in the WHERE clause, the Splunk software uses the default indexes. By default, role-based search filters are applied, but can be turned off in the limits.conf file.

Data manually collected with the tscollect command

You can select data from your namespace by specifying FROM <namespace>. If you did not specify a namespace with the tscollect command, the data is collected into the dispatch directory of that job. If the data is in the dispatch directory, you select the data by specifying FROM sid=<tscollect-job-id>.

An accelerated data model

You can select data from a high-performance analytics store, which is a collection of .tsidx data summaries, for an accelerated data model. You can select data from this accelerated data model by using FROM datamodel=<data_model_name>.<root_dataset_name>.

When you select a data model for a tstats search, you also have to select the root dataset within that data model that you intend to search. You cannot select all of the root datasets within a data model at once.

Search filters cannot be applied to accelerated data models. This includes both role-based and user-based search filters.

A child dataset in an accelerated data model

You can select data from a child dataset within an accelerated data model. Use a WHERE clause to specify the nodename of the child dataset. The nodename argument indicates where the target dataset is in the data model hierarchy. The syntax looks like this:

...| tstats <stats-func> FROM datamodel=<data_model_name>.<root_dataset_name> where nodename=<root_dataset_name>.<...>.<target_dataset_name>

For example, say you have a data model with three root datasets, each with their own dataset hierarchies.

ButtercupGamesPromos
     - NYC (BaseEvent)
          - TShirtStore (NYC)
               - FashionShows (TShirtStore)
               - Giveaways (TShirtStore)
     - Chicago (BaseEvent)
          - BeerAndBrautsPopup (Chicago)
               - BeerSales (BeerAndBrautsPopup)
               - BrautSales (BeerAndBrautsPopup)
     - Tokyo (BaseSearch)
          - GiantRobotBattles (Tokyo)
               - UFORobotGrendizer (GiantRobotBattles)
               - MechaGodzilla (GiantRobotBattles)

With this hierarchy, if you wanted run a tstats search that selects from the dataset containing records of the MechaGodzilla giant robot battles staged by the Tokyo office, you would use the following search:

... | tstats count FROM datamodel=ButtercupGamesPromos.Tokyo where nodename=Tokyo.GiantRobotBattles.MechaGodzilla

Search filters cannot be applied to accelerated data model datasets. This includes both role-based and user-based search filters.

Wildcard characters

The tstats command does not support wildcard characters in field values in aggregate functions or BY clauses.

For example, you cannot specify | tstats avg(foo*) or | tstats count WHERE host=x BY source*.

Aggregate functions include avg(), count(), max(), min(), and sum(). For more information, see Aggregate functions.

Any results returned where the aggregate function or BY clause includes a wildcard character are only the most recent few minutes of data that has not been summarized. Include the summariesonly=t argument with your tstats command to return only summarized data.

Limitations of CIDR matching with tstats

As with the search command, you can use the tstats command to filter events with CIDR match on fields that contain IPv4 and IPv6 addresses. However, unlike the search command, the tstats command may not correctly filter strings containing non-numeric wildcard octets. As a result, your searches may return unpredictable results.

If you are filtering fields with a CIDR match using the tstats command in a BY clause, you can work around this issue and correctly refilter your results by appending your search with a search command, regex command, or WHERE clause. Unfortunately, you can't use this workaround if the search doesn't include the filtered field in a BY clause.

Example of using CIDR match with tstats in a BY clause

Let's take a look at an example of how you could use CIDR match with the tstats command in a BY clause. Say you create a file called data.csv containing the following lines:

ip,description
1.2.3.4,"An IP address"  
5.6.7.8,"Another IP address"  
this.is.a.hostname,"A hostname"  
this.is.another.hostname,"Another hostname"

Then follow these steps:

1. Upload the file and set the sourcetype to csv, which ensures that all fields in the file are indexed as required by the tstats command.
2. Run the following search against the index you specified when you uploaded the file. This example uses the main index.

| tstats count where index=main source=*data.csv ip="0.0.0.0/0" by ip

The results look like this:

ip	count
1.2.3.4	1
5.6.7.8	1
this.is.a.hostname	1
this.is.another.hostname	1

Even though only two addresses are legitimate IP addresses, all four rows of addresses are displayed in the results. Invalid IP addresses are displayed along with the valid IP addresses because the tstats command uses string matching to satisfy search requests and doesn't directly support IP address-based searches. The tstats command does its best to return the correct results for CIDR search clauses, but the tstats search may return more results than you want if the source data contains mixed IP and non-IP data such as host names.

To make sure your searches only return the results you want, make sure that your data set is clean and only contains data in the correct format. If that is not possible, use the search command or WHERE clause to do post-filtering of the search results. For example, the following search using the search command displays correct results because the piped search command further filters the results from the tstats command.

| tstats count where index=main source=*data.csv ip="0.0.0.0/0" by ip | search ip="0.0.0.0/0"

Alternatively, you can use the WHERE clause to filter your results, like this.

| tstats count where index=main source=*data.csv ip="0.0.0.0/0" by ip | WHERE cidrmatch("0.0.0.0/0", ip)

Both of these searches using the search command and the WHERE clause return only the valid IP addresses in the results, which look like this:

ip	count
1.2.3.4	1
5.6.7.8	1

Statistical functions must have named fields

With the exception of count, the tstats command supports only statistical functions that are applied to fields or eval expressions that resolve into fields. For example, you cannot specify | tstats sum or | tstats sum(). Instead the tstats syntax requires that at least one field argument be provided for the function: | tstats sum(<field>).

Nested eval expressions not supported

You cannot use eval expressions inside aggregate functions with the tstats command.

For example, | tstats count(eval(...)) is not supported.

While nested eval expressions are supported with the stats command, they are not supported with the tstats command.

Functions and memory usage

Some functions are inherently more expensive, from a memory standpoint, than other functions. For example, the distinct_count function requires far more memory than the count function. The values and list functions also can consume a lot of memory.

If you are using the distinct_count function without a split-by field or with a low-cardinality split-by by field, consider replacing the distinct_count function with the the estdc function (estimated distinct count). The estdc function might result in significantly lower memory usage and run times.

Use PREFIX() to aggregate or group by raw tokens in indexed data

The PREFIX() directive allows you to search on a raw segment in your indexed data as if it were an extracted field. This causes the search to run over the tsidx file in your indexers rather than the log line. This is a practice that can significantly reduce the CPU load on your indexers.

The PREFIX() directive is similar to the CASE() and TERM() directives in that it matches strings in your raw data. You can use PREFIX() to locate a recurring segment in your raw event data that is actually a key-value pair separated by a delimiter that is also a minor breaker, like = or :. You give PREFIX() the text that precedes the value—the "prefix"—and then it returns the values that follow the prefix. This enables you to group by those values and aggregate them with tstats functions. The values can be strings or purely numeric.

For example, say you have indexed segments in your event data that look like kbps=10 or kbps=333. You can isolate the numerical values in these segments and perform aggregations or group-by operations on them by using the PREFIX() directive to identify kbps= as a common prefix string. Run a tstats search with PREFIX(kbps=) against your event data and it will return 10 and 333. These values are perfect for tstats aggregation functions that require purely numeric input.

Notice that in this example you need to include the = delimiter. If you run PREFIX(kbps), the search returns =10 and =333. Efforts to aggregate on such results may return unexpected results, especially if you are running them through aggregation functions that require purely numeric values.

The text you provide for the PREFIX() directive must be in lower case. For example, the tstats search processor will fail to process PREFIX(connectionType=). Use PREFIX(connectiontype=) instead. It will still match connectionType= strings in your events.

The Splunk software separates events into raw segments when it indexes data, using rules specified in segmenters.conf. You can run the following search to identify raw segments in your indexed events:

| walklex index=<target-index> type=term | stats sum(count) by term

You cannot apply the PREFIX() directive to segment prefixes and values that contain major breakers such as spaces, square or curly brackets, parenthesis, semicolons, or exclamation points.

For more information about the CASE() and TERM() directives, see Use CASE() and TERM() to match phrases in the Search Manual.

For more information about the segmentation of indexed events, see About event segmentation in Getting Data In

For more information about minor and major breakers in segments, see Event segmentation and searching in the Search Manual.

Memory and tstats search performance

A pair of limits.conf settings strike a balance between the performance of tstats searches and the amount of memory they use during the search process, in RAM and on disk. If your tstats searches are consistently slow to complete you can adjust these settings to improve their performance, but at the cost of increased search-time memory usage, which can lead to search failures.

If you have Splunk Cloud you will need to file a Support ticket to change these settings.

For more information, see Memory and stats search performance in the Search Manual.

Complex aggregate functions

The tstats command does not support complex aggregate functions such as ...count(eval('Authentication.action'=="failure")).

Consider the following query. This query will not return accurate results because complex aggregate functions are not supported by the tstats command.

| tstats count(eval(server.status=200)) from datamodel=internal_server.server where nodename=server.splunkdaccess by server.status uri

Instead, separate out the aggregate functions from the eval functions, as shown in the following search.

| tstats count from datamodel=internal_server.server where nodename=server.splunkdaccess by server.status, uri | eval success=if('server.status'="200", count, 0) | stats sum(success) as success by uri

The results from this search look something like this:

uri	success
//services/cluster/config?output_mode=json	0
//services/cluster/config?output_mode=json	2862
/services/admin/kvstore-collectionstats?count=0	1
/services/admin/transforms-lookup?count=0&getsize=true	1

Sparkline charts

You can generate sparkline charts with the tstats command only if you specify the _time field in the BY clause and use the stats command to generate the actual sparkline. For example:

| tstats count from datamodel=Authentication.Authentication BY _time, Authentication.src span=1h | stats sparkline(sum(count),1h) AS sparkline, sum(count) AS count BY Authentication.src

Filtering with WHERE

You can provide any number of aggregates (aggregate-opt) to perform and also have the option of providing a filtering query using the WHERE keyword. This query looks like a normal query you would use in the search processor. This supports all the same time arguments as search, such as earliest=-1y.

Grouping by _time

You can provide any number of BY fields. If you are grouping by _time, supply a timespan with span for grouping the time buckets, for example ...BY _time span=1h or ...BY _time span=3d.

Tstats and tsidx bucket reduction

tstats searches over indexes that have undergone tsidx bucket reduction will return incorrect results.

For more information see Reduce tsidx disk usage in Managing indexers and clusters of indexers.

Multiple time ranges

The tstats command is unable to handle multiple time ranges. This is because the tstats command is a generating command and doesn't perform post-search filtering, which is required to return results for multiple time ranges.

The following example of a search using the tstats command on events with relative times of 5 seconds to 1 second in the past displays a warning that the results may be incorrect because the tstats command doesn't support multiple time ranges.

| tstats count where index="_internal" (earliest =-5s latest=-4s) OR (earliest=-3s latest=-1s)

If you want to search events in multiple time ranges, use another command such as stats, or use multiple tstats commands with append as shown in the following example.

| tstats prestats=t count where index=_internal earliest=-5s latest=-4s | tstats prestats=t append=true count where index=_internal earliest=-3s latest=-2s | stats count

The results in this example look something like this.

count
264

The tstats command doesn't respect the srchTimeWin parameter

The tstats command doesn't respect the srchTimeWin parameter in the authorize.conf file and other role-based access controls that are intended to improve search performance. This is because the tstats command is already optimized for performance, which makes parameters like srchTimeWin irrelevant.

For example, say you previously set the srchTimeWin parameter on a role for one of your users named Alex, so he is just allowed to run searches back over 1 day. You limited the search time range to prevent searches from running over longer periods of time, which could potentially impact overall system performance and slow down searches for other users. Alex has been running a stats search, but didn't notice that he was getting results for just 1 day, even though he specified 30 days. If Alex then changes his search to a tstats search, or changes his search in such a way that Splunk software automatically optimizes it to a tstats search, the 1 day setting for the srchTimeWin parameter no longer applies. As a result, Alex gets many times more results than before, since his search is returning all 30 days of events, not just 1 day of results. This is expected behavior.

Examples

Example 1: Gets the count of all events in the mydata namespace.

| tstats count FROM mydata

Example 2: Returns the average of the field foo in mydata, specifically where bar is value2 and the value of baz is greater than 5.

| tstats avg(foo) FROM mydata WHERE bar=value2 baz>5

Example 3: Gives the count by source for events with host=x.

| tstats count WHERE host=x BY source

Example 4: Gives a timechart of all the data in your default indexes with a day granularity.

| tstats prestats=t count BY _time span=1d | timechart span=1d count

Example 5: Use prestats mode in conjunction with append to compute the median values of foo and bar, which are in different namespaces.

| tstats prestats=t median(foo) FROM mydata | tstats prestats=t append=t median(bar) FROM otherdata | stats median(foo) median(bar)

Example 6: Uses the summariesonly argument to get the time range of the summary for an accelerated data model named mydm.

| tstats summariesonly=t min(_time) AS min, max(_time) AS max FROM datamodel=mydm | eval prettymin=strftime(min, "%c") | eval prettymax=strftime(max, "%c")

Example 7: Uses summariesonly in conjunction with timechart to reveal what data has been summarized over the past hour for an accelerated data model titled mydm.

| tstats summariesonly=t prestats=t count FROM datamodel=mydm BY _time span=1h | timechart span=1h count

Example 8: Uses the values statistical function to provide a list of all distinct values for source returned by the "Splunk's Internal Server Logs" data model. The list is returned as a multivalue entry.

| tstats values(source) FROM datamodel=internal_server

The results look something like this:

values(source)
/Applications/Splunk/var/log/splunk/license_usage.log /Applications/Splunk/var/log/splunk/metrics.log /Applications/Splunk/var/log/splunk/metrics.log.1 /Applications/Splunk/var/log/splunk/scheduler.log /Applications/Splunk/var/log/splunk/splunkd.log /Applications/Splunk/var/log/splunk/splunkd_access.log

If you don't have the internal_server data model defined, check under Settings->Data models for a list of the data models you have access to.

Example 9: Uses the values statistical function to provide provide a list of all distinct values for source returned by the Alerts dataset within the "Splunk's Internal Server Logs" data model.

| tstats values(source) FROM datamodel=internal_server where nodename=server.scheduler.alerts

Example 10: Gets the count and average of a raw, unindexed term using the PREFIX kbps=, then splits this by an indexed source and another unindexed term using the PREFIX group=.

| tstats count avg(PREFIX(kbps=)) where index=_internal by source PREFIX(group=)

See also

Commands

datamodel

stats

tscollect

walklex