I'm trying to create custom grok patterns to extract various data using logstash and am wracking my brain getting the syntax correct to pull the regex group 1 equivalent from my log rows. I've looked at a ton of threads on this over the past 2 days, but nothing's out there that fits my example, and none of the canned grok patterns seem like they will pull the value I need.
3 example log file rows look similar to this (with abbreviated data for the examples):
2022-04-07 12:52:06,184:INFO :Thread-70_SCHEDULE.0001: MsgID=63759111848731967
2022-04-07 07:23:39,876:INFO :Thread-53_OrderInterfaceIntServer: MsgID=21316889724753182|
07:23:40,482 INFO [stdout] (http-/0.0.0.0:8080-20) 2022-04-07 07:23:40,482:ERROR
I want to create a custom grok pattern called SERVICE that extracts a pattern match using a regex match string:
Thread-[0-9]{2}_(.*?)\:
that for the 3 rows would return:
SCHEDULE.0001
OrderInterfaceIntServer
""
In the log:
SERVICE will always be prefixed by "Thread-xx_" where xx = 2-digit number followed by underscore. Some logs may not have this pattern at all (like row 3). In that case, no match.
SERVICE is always followed by a colon
In grok, I can define this in 2 ways:
SERVICE Thread-[0-9]{2}_(.*?)\:
or as a field using (?<service>Thread-[0-9]{2}_(.*?)\:)
however, for row 1, I get the response value of:
{
"service": [
[
"Thread-70_SCHEDULE.0001:"
]
]
}
What I want is:
{
"service": [
[
"SCHEDULE.0001"
]
]
}
Which is the equivalent of the regex group 1 response. I can't figure out how to manage the grok patterns to get the result I need.
You do not have to include all of the pattern in the capture group. You can use
grok { match => { "message" => "Thread-[0-9]{2}_(?<service>.*?):" } }
That will result in
"service" => "SCHEDULE.0001",
"service" => "OrderInterfaceIntServer",
and a "_grokparsefailure" tag on the third event.
Related
Ive recently began learning logstash and the syntax is confusing me.
eg : for match i have various codes:
match => [ "%{[date]}" , "YYYY-MM-dd HH:mm:ss" ]
match => { "message" => "%{COMBINEDAPACHELOG}" }
match => [ "timestamp" , "dd/MMM/yyyy:HH:mm:ss Z" ]
What does each of these keys ("%{[date]}", "message", "timestamp") mean. And where can i find a proper documentation that explains all the keywords and syntax.
Please help and provide links if possible.
The grok{} filter has a match parameter that takes a field and a pattern. It will apply the pattern, trying to extract new fields from it. Your second example is from grok, so it will try to apply the COMBINEDAPACHELOG pattern against the text in the "message" field.
The doc for grok{} is here, and there are detailed blogs, too.
The other two examples look like they're from the date{} filter, which does a similar thing. It takes a field containing a string that represents a date, applies the given pattern to that field, and (by default) replaces the value in the #timestamp field.
The doc for date{} is here and examples here.
I am trying to take log data from a custom application that has a well defined format. I am trying to pick out certain pieces of the data using the grok filter, but I am not having any luck. Here is a sample log:
- System.Data.SqlClient.SqlException (0x80131904): Arithmetic overflow error converting IDENTITY to data type int.
Arithmetic overflow occurred.
What I would like to do is extract out the SqlException out of the string. Here is the grok that I am using:
grok{
match =>
{
"message" =>
[
"(?m)%{DATE:TIMESTAMP_DATE}%{SPACE}%{TIME:TIMESTAMP_TIME}%{SPACE}%{WORD:LOG_LEVEL}%{SPACE}(?<THREAD>[^\s]+)%{SPACE}(?<HOST>[^\s]+)%{SPACE}%{GREEDYDATA:MESSAGE}",
"(?<EXCEPTION>[.*]+)"
]
}
}
I have tried several different ways, but I guess I am not completely understanding the documentation. What I would expect to happen is all of the fields that I have extracts in the first set would include the result of the second set. In other words:
TIMESTAMP_DATE,TIMESTAMP_TIME,LOG_LEVEL,THREAD,HOST,MESSAGE,EXCEPTION
I am getting the other fields perfectly, it is just additional matching that I am missing. Any help would be appreciated. Thanks
If you specify multiple patterns grok by default only looks checks the patterns until the first match is encountered. If you want to match against both patterns regardless of whether the first one matched or not you can change the behaviour like that:
grok{
break_on_match => false
match =>
{
"message" =>
[
"(?m)%{DATE:TIMESTAMP_DATE}%{SPACE}%{TIME:TIMESTAMP_TIME}%{SPACE}%{WORD:LOG_LEVEL}%{SPACE}(?<THREAD>[^\s]+)%{SPACE}(?<HOST>[^\s]+)%{SPACE}%{GREEDYDATA:MESSAGE}",
"(?<EXCEPTION>[.*]+)"
]
}
}
Check out the docs under: https://www.elastic.co/guide/en/logstash/current/plugins-filters-grok.html#plugins-filters-grok-break_on_match
setting up ELK is very easy until you hit the logstash filter. I have a log delimited 10 fields. I may have some field blank but I am sure there will be 10 fields:
7/5/2015 10:10:18 AM|KDCVISH01|
|ClassNameUnavailable:MethodNameUnavailable|CustomerView|xwz261|ef315792-5c41-4bdf-aa66-73317e82e4d6|52|6182d1a1-7916-4874-995b-bc9a23437dab|<Exception>
afkh akla 487234 &*<Exception>
Q:
1- I am confused how grok or regex pattern will pick only the field that I am looking and not the similar match from another field. For example, what is the guarantee that DATESTAMP pattern picks only the first value and not the timestamp present in the last field (buried in stack trace)?
2- Is there a way to define positional mapping? For example, 1st fiels is dateTime, 2nd is machine name, 3rd is class name and so on. This will make sure I have fields displayed in Kibana no matter the field value is present or not.
I know i am little late, But here is a simple solution which i am using,
replace your | with space
option 1:
filter {
mutate {
gsub => ["message","\|"," "]
}
grok {
match => ["message","%{DATESTAMP:time} %{WORD:MESSAGE1} %{WORD:EXCEPTION} %{WORD:MESSAGE2}"]
}
}
option 2: excepting |
filter {
grok {
match => ["message","%{DATESTAMP:time}\|%{WORD:MESSAGE1}\|%{WORD:EXCEPTION}\|%{WORD:MESSAGE2}"]
}
}
it is working fine : http://grokdebug.herokuapp.com/. check here.
I have a log file which contains lines which begin with a timestamp. An uncertain number of extra lines might follow each such timestamped line:
SOMETIMESTAMP some data
extra line 1 2
extra line 3 4
The extra lines would provide supplementary information for the timestamped line. I want to extract the 1, 2, 3, and 4 and save them as variables. I can parse the extra lines into variables if I know how many of them there are. For example, if I know there are two extra lines, the grok filter below will work. But what should I do if I don't know, in advance, how many extra lines will exist? Is there some way to parse these lines one-by-one, before applying the multiline filter? That might help.
Also, even if I know I will only have 2 extra lines, is the filter below the best way to access them?
filter {
multiline {
pattern => "^%{SOMETIMESTAMP}"
negate => "true"
what => "previous"
}
if "multiline" in [tags] {
grok {
match => { "message" => "(?m)^%{SOMETIMESTAMP} %{DATA:firstline}(?<newline>[\r\n]+)%{DATA:secondline}(?<newline>[\r\n]+)%{DATA:thirdline}$" }
}
}
# After this would be grok filters to process the contents of
# 'firstline', 'secondline', and 'thirdline'. I would then remove
# these three temporary fields from the final output.
}
(I separated the lines into separate variables since this allows me to do additional pattern matching on the contents of the lines separately, without having to refer to the entire pattern all over again. For example, based on the contents of the first line, I might want to present branching behavior for the other lines.)
Why do you need this?
Are you going to be inserting one single event with all of the values or are they really separate events that just need to share the same time stamp?
If they all need to appear in the same event, you'll like need to resort to a ruby filter to separate out the extra lines into fields on the event that you can then further work on.
For example:
if "multiline" in [tags] {
grok {
match => { "message" => "(?m)^%{SOMETIMESTAMP} %{DATA:firstline}(?<newline>[\r\n]+)" }
}
ruby {
code => '
event["lines"] = event["message"].scan(/[^\r\n]+[\r\n]*/);
'
}
}
If they are really separate events, you could use the memorize plugin for logstash 1.5 and later.
This has changed over versions of ELK
Direct event field references (i.e. event['field']) have been disabled in favor of using event get and set methods (e.g. event.get('field')).
filter {
grok {
match => { "message" => "%{TIMESTAMP_ISO8601:logtime} %{LOGLEVEL:level}%{DATA:firstline}" }
}
ruby { code => "event.set('message', event.get('message').scan(/[^\r\n]+[\r\n]*/))" }
}
My log file contains different structures in a few lines, and I can not grok it, I don't know if we can test by lines or attribute, I'm still a beginner.
if you don't understand me I can give you some examples :
input :
id=firewall action=bloc type=web
id=firewall fw="ER" type=filter
id=firewall fw="Az" tz="loo" action=bloc
Pattern:
id=%{WORD:id} ...
I thought to add some patterns between ()?,
but i don't know exactly how to do it.
you can use this site to test it http://grokdebug.herokuapp.com/
Any help please? What should i do :(
Logstash supports key-value Values, take a look at http://logstash.net/docs/1.4.2/filters/kv.
Or you could use multiple match values:
grok {
patterns_dir => "./patterns"
match => [
"message", "%{BASE_PATTERN} %{EXTRA_PATTERN}",
"message", "%{BASE_PATTERN}",
"message", "%{SOME_OTHER_PATTERN}"
]
}
Not sure if I understood well your question but I will try to answer. I think the first thing you have to do is to parse the different fields from your input. Example of pattern to parse your first line input :
PATTERN %{NOTSPACE} %{NOTSPACE} %{NOTSPACE} (in $LOGSTASH_HOME/pattern/extra)
Then in your logstash configuration file :
filter {
grok {
patterns_dir => "$LOGSTASH_HOME/pattern"
match => [ "message" => "%{PATTERN}" ]
}
}
This will match your first line as 3 fields ("id=firewall" "action=bloc" "type=web") (you have to adapt it if you have more than 3 fields).
And the last thing you seem be looking for is splitting field (in key-value scheme) like id=firewall would become id => "firewall". This can be done with the kv plugin. I never used it but I recommend you the logstash docs here
If I did not understand you question, please be more clear.