I have a sample input like below.
[2022-01-06 19:51:42,143] [http-nio-8080-exec-7] DEBUG [50a4f8740c30b9ca,c1b11682-1eeb-4538-b7f6-d0fb261b3e1d]
I implemented a grok filter to validate the text.
\[%{TIMESTAMP_ISO8601:timestamp}\] \[(?<threadname>[^\]]+)\] %{LOGLEVEL:logLevel} \[%{WORD:traceId},%{WORD:correlationId}\]
When I validate it, it says there are no matches.
But If I remove - in correlation id, that filter is working fine. Is there any modification to do to the filter to accept - in the correlation id?
Try this.
\[%{TIMESTAMP_ISO8601:timestamp}\] \[%{DATA:threadName}\] %{LOGLEVEL:logLevel} \[%{DATA:traceId},%{DATA:correlationId}\]
Acording to this %{WORD} pattern is defined by this regular expression \b\w+\b
\w captures alphanumeric
\b captures word boundaries. It helps you to perform whole words only
So if your original text contains a - it will never be capturing it.
You can try %{DATA} instead as it captures .*?
Related
My grok expression works fine when used with the matching string alone but when I use this grok expression with other grok expressions to capture other data that's also present in the log line, it doesn't match with the same matching string.
Case1: Below grok expression is working fine when running alone for the below log string and the value is captured in the field targetMessage
Log string: Tracking : sent request to msgDestination
Grok expression: (?<targetMessage>^Tracking : (?:received response from|sent request to) msgDestination$)
Case2: When I try to run the expression with other some other data also present in the log string it doesn't work i.e. grok expression doesn't match with the same string as used above.
Log string:
2022-11-26 8:16:39,873 INFO [task.SomeTask] Tracking : sent request to msgDestination : MODULE1|SERVICE1|20220330051054|TASK1
Grok expression: %{TIMESTAMP_ISO8601:timestamp} %{LOGLEVEL:loglevel} \[(?<classname>[^\]]+)\] (?<targetMessage>^Tracking : (?:received response from|sent request to) msgDestination$) : %{WORD:moduleName}\|%{WORD:service}\|%{INT:requestId}\|%{WORD:taskName}
Debug tool used: https://grokdebug.herokuapp.com/
If anyone can please suggest what mistake I'm making here?
^ and $ anchor an expression to the start and end of a line respectively. You have both inside the targetMessage custom pattern, and that is in the middle of the line, so neither one matches. Remove both ^ and $
I have a log entry whose last part keeps changing depending on few HTTPS conditions.
sample Logs:
INFO [2021-09-27 23:07:58,632] [dw-1001 - POST /abc/api/v3/pqr/options] [386512709095023:] [ESC[36mUnicornClientESC[0;39m]:
<"type": followed by 11000 characters including space words symbols <----- variable length.
grok pattern:
%{LOGLEVEL:loglevel}\s*\[%{TIMESTAMP_ISO8601:date}\]\s*\[%{GREEDYDATA:requestinfo}\]\s*\[%{GREEDYDATA:logging_id}\:%{GREEDYDATA:token}\]\s*\[(?<method>[^\]]+)\]\:\s*(?<messagebody>(.|\r|\n)*)
(.|\r|\n)*)
this works fine if the variable part of the log is small, but when a large log is encountered, it throws an exception:
[2021-09-27T17:24:40,867][WARN ][logstash.filters.grok ] Timeout executing grok '%{LOGLEVEL:loglevel}\s*\[%{TIMESTAMP_ISO8601:date}\]\s*\[%{GREEDYDATA:requestinfo}\]\s*\[%{GREEDYDATA:logging_id}\:%{GREEDYDATA:token}\]\s*\[(?<method>[^\]]+)\]\:\s*(?<messagebody>(.|\r|\n)*)' against field 'message' with value 'Value too large to output (178493 bytes)! First 255 chars are: INFO [2021-09-27 11:50:14,005] [dw-398 - POST /xxxxx/api/v3/xxxxx/options] [e3acfd76-28a6-0000-0946-0c335230a57e:]
and CPU starts choking and persistent queue increases and Lag in kibana. Any suggestions?
Performance problems in grok and timeouts are not usually a problem when the pattern matches the message, they are a problem when the pattern fails to match.
The first thing to do is anchor your patterns if possible. This blog post has performance data on how effective this is. In your case, when the pattern does not match, grok will start at the beginning of the line to see if LOGLEVEL matches. If it does NOT match, then it will start at the second character of the line and see if LOGLEVEL matches. If it keeps not matching it will have to make thousands of attempts to match the pattern, which is really expensive. If you change your pattern to start with ^%{LOGLEVEL:loglevel}\s*\[ then the ^ means that grok only has to evaluate the match against LOGLEVEL at the start of each line of [message]. If you change it to be "\A%{LOGLEVEL:loglevel}\s*\[ then it will only evaluate the match at the very beginning of the [message] field.
Secondly, if possible, avoid GREEDYDATA except at the end of the pattern. When matching a 10 KB string against a pattern that has multiple GREEDYDATAs, if the pattern does not match then each GREEDYDATA will be tried against thousands of different substrings, resulting in millions of attempts to do the match for each event (it's not quite this simple, but failing to match does get very expensive). Try changing GREEDYDATA to DATA and if it still works then keep it.
Thirdly, if possible, replace GREEDYDATA/DATA with a custom pattern. For example, it appears to me that \[%{GREEDYDATA:requestinfo}\] could be replaced with \[(?<requestinfo>[^\]]+) and I would expect that to be cheaper when the overall pattern does not match.
Fourthly, I would seriously consider using dissect rather than grok
dissect { mapping => { "message" => "%{loglevel->} [%{date}] [%{requestinfo}] [%{logging_id}:%{token}] [%{method}]: %{messagebody}" } }
However, there is a bug in the dissect filter where if "->" is used in the mapping then a single delimiter does not match, multiple delimiters are required. Thus that %{loglevel->} would match against INFO [2021, but not against ERROR [2021. I usually do
mutate { gsub => [ "message", "\s+", " " ] }
and remove the -> to workaround this. dissect is far less flexible and far less powerful than grok, which makes is much cheaper. Note that dissect will create empty fields, like grok with keep_empty_captures enabled, so you will get a [token] field that contains "" for that message.
Below is the field that is filebeat log path, that I need to split with delimiter '/' and remove the log file name in the text.
"source" : "/var/log/test/testapp/c.log"
I need only this part
"newfield" : "/var/log/test/testapp"
If you do a little of research you can find that this is a trivial question and it has not much complexity. You can use grok-patterns to match the interesting parts and differentiate the one you want to retrieve from the one you don't.
A pattern like this will match as you expected, having the newfield as you desire:
%{GREEDYDATA:newfield}(/%{DATA}.log)
Anyway, you can test your Grok patterns with this tool, and here you have some usefull grok-patterns. I recommend you to take a look to those resources.
I have this for example:
<#445288012218368010>
And I want to get from between <# > symbols the value.
I tried so:
string.replace(/^(?:\<\#)(?:.*)(?:\>)$/gim, '');
But then I don't get any result. It will delete/remove the whole string.
I want only this part: 445288012218368010 (it will be dynamic, so yeah it will be not the same numbers).
Anyway it is for the discord chat bot and I know that there is other methods for check the mentioned names but I want to do that in regex because which I am trying to do can't go the common method.
So yeah how can I get the value from between those symbols?
I need this in node.js regex.
You can use String#match which will return regular expression matches for the string (in this case the RegExp would be <#(\d+)> (the parenthesis around the \d+ make \d+ become its own group). This way you can use <string>.match(/<#(\d+)>/) to get the regular expression results and <string>.match(/<#(\d+)>/)[1] to get the first group of the regex (in this case the number).
You regex matches but you use a non capturing group (?:.*) so you get the full match and replace that with an empty string. Note that you could omit the first and the third non capturing group and use <# and > instead.
You could match what is between the brackets using a capturing group ([^>]+) or (\d+) and use replace and refer the first capturing group $1 in the replacement.
console.log("<#445288012218368010>".replace(/^<#([^>]+)>$/gim, '$1'));
I am trying to parse below log using grok
[2018-10-06 12:04:03:0227] [MYMACHINENAME]
and the grok expression which I used is
/[%{DATESTAMP:date}/] /[%{WORD:data}%/]
and this expression is not working. I tried to replace WORD with hostname even then it not working and if I try to either of the matchers alone then it works.
Can anyone provide me the better tutorial pages to learn grok expressions?
There are few errors in your pattern.
First off, you escape character using backslash / not forward slash \. Second, you don't need % to match ] in the end.
Third, DATESTAMP doesn't match your date pattern, you need TIMESTAMP_ISO8601.
Your final pattern should become,
\[%{TIMESTAMP_ISO8601}\] \[%{WORD}\]
Regex pattern DATESTAMP is not correct for your string. Try using TIMESTAMP_ISO8601.
Here you can see all grok regex patterns: grok-patterns.