@saranyaa21, based on the sample data provided, seems like you are traversing JSON data.Ideally for the sourcetype=serverlog, if you are only interested in JSON data, you should try either INDEXEDEXTRACTIONS=JSON or else KVMODE=json in your props.conf. But not both.In order to test the same at Search time you can try the following run anywhere search with spath to reveal all the.
- Splunk Regex Cheat Sheet Pdf
- Regex Cheat Sheet Pdf
- C# Regex Cheat Sheet
- Splunk Regex Cheat Sheet Pdf
- Splunk Regex Filter
- LINEBREAKER = regular expression for event breaks TRUNCATE = 999999 (always a high number). Splunk® Data Onboarding Cheat Sheet (v2.5) v2.5.2. Review The Data.
- Splunk-cheat-sheet AND,OR operator in splunk search Splunk Top command wildcards in splunk search dedup command head and tail stats eval Splunk Search book README.md Splunk-cheat-sheet.
- Matches regex (2) regex: matches regex: In Splunk, regex is an operator. In Azure Monitor, it's a relational operator. Searchmatch In Splunk, searchmatch allows searching for the exact string. Random: rand rand(n) Splunk's function returns a number from zero to 2 31-1. Azure Monitor' returns a number between 0.0 and 1.0, or if a parameter.
- So the next question popping in your mind is should i need to lean regex for using splunk.then answer is it depends.For using and operating splunk you do not need to learn regex in detail - basic knowledge will be ok.But if you want to become a skilled splunk admin then learning regex is necessary.
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Splunk regex tutorial | field extraction using regex
So basically regex used to identify fields and list them in proper manner which later can be used for reporting,sorting and dashboard.Below image will help you in understanding the scenario
Why Regex?
Regex is helpful in transforming your horrible looking machine logs into beautiful human understandable reports and dashboard -Easy to understand and use.Shown as below.
How to regex?
Splunk automatically identifies any fields that match its key/value pair intelligence, which can be found to the left of the search results as below. This can often allow you to start putting together useful data visualizations right out of the box.In below screenshot splunk has automatically extracted host,timestamp etc values.We can use these values for reporting,statistical analysis and creating dashboards.Splunk has inbuilt regex extractor called IFX (Interactive field extractor).By using IFX splunk autodetects useful fields and list them at left side.Splunk IFX can extract fields automatically which are in standard key value pair format i.e. key=value format like username=john etc.But if logs are not in key value pair format then you have to teach splunk to extract fields which you wan using regex.
How to extract fields using regex?
- Good regex sites to help with Splunk
- https://regex101.com/ - Great for general regex stuff and capture groups.
- http://www.regexe.com/ - Great for dealing with capture groups in the way that Splunk likes them for anonymising data.
- http://regexr.com/ - Classic website for quick PoC regexs.
Below are few commonly used regex notations while using extracting keywords using regex manually:
Splunk Regex Cheat Sheet Pdf
Regex Cheat Sheet Pdf

This article is intended to assist users who are familiar with Splunk learn the Kusto Query Language to write log queries with Kusto. Direct comparisons are made between the two to highlight key differences and similarities, so you can build on your existing knowledge.
Structure and concepts
The following table compares concepts and data structures between Splunk and Kusto logs:
C# Regex Cheat Sheet
Concept | Splunk | Kusto | Comment |
---|---|---|---|
deployment unit | cluster | cluster | Kusto allows arbitrary cross-cluster queries. Splunk does not. |
data caches | buckets | caching and retention policies | Controls the period and caching level for the data. This setting directly affects the performance of queries and the cost of the deployment. |
logical partition of data | index | database | Allows logical separation of the data. Both implementations allow unions and joining across these partitions. |
structured event metadata | N/A | table | Splunk doesn't expose the concept of event metadata to the search language. Kusto logs have the concept of a table, which has columns. Each event instance is mapped to a row. |
data record | event | row | Terminology change only. |
data record attribute | field | column | In Kusto, this setting is predefined as part of the table structure. In Splunk, each event has its own set of fields. |
types | datatype | datatype | Kusto data types are more explicit because they're set on the columns. Both have the ability to work dynamically with data types and roughly equivalent set of datatypes, including JSON support. |
query and search | search | query | Concepts essentially are the same between Kusto and Splunk. |
event ingestion time | system time | ingestion_time() | In Splunk, each event gets a system timestamp of the time the event was indexed. In Kusto, you can define a policy called ingestion_time that exposes a system column that can be referenced through the ingestion_time() function. |
Functions
The following table specifies functions in Kusto that are equivalent to Splunk functions.
Splunk | Kusto | Comment |
---|---|---|
strcat | strcat() | (1) |
split | split() | (1) |
if | iff() | (1) |
tonumber | todouble() tolong() toint() | (1) |
upper lower | toupper() tolower() | (1) |
replace | replace() | (1) Also note that although replace() takes three parameters in both products, the parameters are different. |
substr | substring() | (1) Also note that Splunk uses one-based indices. Kusto notes zero-based indices. |
tolower | tolower() | (1) |
toupper | toupper() | (1) |
match | matches regex | (2) |
regex | matches regex | In Splunk, regex is an operator. In Kusto, it's a relational operator. |
searchmatch | In Splunk, searchmatch allows searching for the exact string. | |
random | rand() rand(n) | Splunk's function returns a number between zero to 231-1. Kusto's returns a number between 0.0 and 1.0, or if a parameter is provided, between 0 and n-1. |
now | now() | (1) |
relative_time | totimespan() | (1) In Kusto, Splunk's equivalent of relative_time(datetimeVal, offsetVal) is datetimeVal + totimespan(offsetVal) .For example, search | eval n=relative_time(now(), '-1d@d') becomes ... | extend myTime = now() - totimespan('1d') . |
(1) In Splunk, the function is invoked by using the eval
operator. In Kusto, it's used as part of extend
or project
.
(2) In Splunk, the function is invoked by using the eval
operator. In Kusto, it can be used with the where
operator.
Operators
The following sections give examples of how to use different operators in Splunk and Kusto.
Note
In the following examples, the Splunk field rule
maps to a table in Kusto, and Splunk's default timestamp maps to the Logs Analytics ingestion_time()
column.
Search
In Splunk, you can omit the search
keyword and specify an unquoted string. In Kusto, you must start each query with find
, an unquoted string is a column name, and the lookup value must be a quoted string.
Product | Operator | Example |
---|---|---|
Splunk | search | search Session.Id='c8894ffd-e684-43c9-9125-42adc25cd3fc' earliest=-24h |
Kusto | find | find Session.Id'c8894ffd-e684-43c9-9125-42adc25cd3fc' and ingestion_time()> ago(24h) |
Filter
Kusto log queries start from a tabular result set in which filter
is applied. In Splunk, filtering is the default operation on the current index. You also can use the where
operator in Splunk, but we don't recommend it.
Product | Operator | Example |
---|---|---|
Splunk | search | Event.Rule='330009.2' Session.Id='c8894ffd-e684-43c9-9125-42adc25cd3fc' _indextime>-24h |
Kusto | where | Office_Hub_OHubBGTaskError | where Session_Id 'c8894ffd-e684-43c9-9125-42adc25cd3fc' and ingestion_time() > ago(24h) |
Get n events or rows for inspection
Kusto log queries also support take
as an alias to limit
. In Splunk, if the results are ordered, head
returns the first n results. In Kusto, limit
isn't ordered, but it returns the first n rows that are found.
Product | Operator | Example |
---|---|---|
Splunk | head | Event.Rule=330009.2 | head 100 |
Kusto | limit | Office_Hub_OHubBGTaskError | limit 100 |
Get the first n events or rows ordered by a field or column
For the bottom results, in Splunk, you use tail
. In Kusto, you can specify ordering direction by using asc
.
Product | Operator | Example |
---|---|---|
Splunk | head | Event.Rule='330009.2' | sort Event.Sequence | head 20 |
Kusto | top | Office_Hub_OHubBGTaskError | top 20 by Event_Sequence |
Extend the result set with new fields or columns

Splunk has an eval
function, but it's not comparable to the eval
operator in Kusto. Both the eval
operator in Splunk and the extend
operator in Kusto support only scalar functions and arithmetic operators.
Product | Operator | Example |
---|---|---|
Splunk | eval | Event.Rule=330009.2 | eval state= if(Data.Exception = '0', 'success', 'error') |
Kusto | extend | Office_Hub_OHubBGTaskError | extend state = iif(Data_Exception 0,'success' ,'error') |

Rename
Kusto uses the project-rename
operator to rename a field. In the project-rename
operator, a query can take advantage of any indexes that are prebuilt for a field. Splunk has a rename
operator that does the same.
Product | Operator | Example |
---|---|---|
Splunk | rename | Event.Rule=330009.2 | rename Date.Exception as execption |
Kusto | project-rename | Office_Hub_OHubBGTaskError | project-rename exception = Date_Exception |
Format results and projection
Splunk doesn't appear to have an operator that's similar to project-away
. You can use the UI to filter out fields.
Product | Operator | Example |
---|---|---|
Splunk | table | Event.Rule=330009.2 | table rule, state |
Kusto | project project-away | Office_Hub_OHubBGTaskError | project exception, state |
Aggregation
See the list of aggregations functions that are available.
Product | Operator | Example |
---|---|---|
Splunk | stats | search (Rule=120502.*) | stats count by OSEnv, Audience |
Kusto | summarize | Office_Hub_OHubBGTaskError | summarize count() by App_Platform, Release_Audience |
Join
join
in Splunk has substantial limitations. The subquery has a limit of 10,000 results (set in the deployment configuration file), and a limited number of join flavors are available.
Product | Operator | Example |
---|---|---|
Splunk | join | Event.Rule=120103* | stats by Client.Id, Data.Alias | join Client.Id max=0 [search earliest=-24h Event.Rule='150310.0' Data.Hresult=-2147221040] |
Kusto | join | cluster('OAriaPPT').database('Office PowerPoint').Office_PowerPoint_PPT_Exceptions | where Data_Hresult -2147221040 | join kind = inner (Office_System_SystemHealthMetadata | summarize by Client_Id, Data_Alias)on Client_Id |
Sort
In Splunk, to sort in ascending order, you must use the reverse
operator. Kusto also supports defining where to put nulls, either at the beginning or at the end.
Product | Operator | Example |
---|---|---|
Splunk | sort | Event.Rule=120103 | sort Data.Hresult | reverse |
Kusto | order by | Office_Hub_OHubBGTaskError | order by Data_Hresult, desc |
Multivalue expand
The multivalue expand operator is similar in both Splunk and Kusto.

Splunk Regex Cheat Sheet Pdf
Product | Operator | Example |
---|---|---|
Splunk | mvexpand | mvexpand solutions |
Kusto | mv-expand | mv-expand solutions |
Result facets, interesting fields
In Log Analytics in the Azure portal, only the first column is exposed. All columns are available through the API.
Product | Operator | Example |
---|---|---|
Splunk | fields | Event.Rule=330009.2 | fields App.Version, App.Platform |
Kusto | facets | Office_Excel_BI_PivotTableCreate | facet by App_Branch, App_Version |
Deduplicate
In Kusto, you can use summarize arg_min()
to reverse the order of which record is chosen.
Splunk Regex Filter
Product | Operator | Example |
---|---|---|
Splunk | dedup | Event.Rule=330009.2 | dedup device_id sortby -batterylife |
Kusto | summarize arg_max() | Office_Excel_BI_PivotTableCreate | summarize arg_max(batterylife, *) by device_id |
Next steps
- Walk through a tutorial on the Kusto Query Language.
