I am wondering if it is possible for logstash to ignore first 2 lines of a file? I have looked in many places and the only solution seems to be using an if to check if the line is certain text, and if so drop .. but this seems extremely inefficient as I know for a fact I only need to drop first 2 lines and dont need to "if..then" check millions or even thousands of lines that follow.
Thanks.
The simple answer is no, not with the existing versions. The logstash file input only has an option for start_postition => beginning.
If you feel strongly about it, you could always fork the file input, update it with a start_position => skip_lines, add another parameter to specify how many lines, and then submit a pull request back to Elastic and it might get implemented.
Related
I'm processing a log file with the help of logstash aggregate filter with grok having multiple patterns.
Now while processing the logs I want to extract a part of the log with some regex and store it into a file.
For example, let's say my log is :
id:0422 time:[2013-11-19 02:34:58] level:INFO text:(Lorem Ipsum is simply dummy text of the printing and typesetting industry)
In this log the text will be different at every time.
I have a regex with help of it I can match a part of text that can occure in logstash
So if I find something in that text with help of that regex while logstash indexing into elastic I want to store it into some file or something
Is it possible to achieve this?
There are different solutions for this:
create a filter using ruby code that will be triggered to write in a specific format when you have all the event data together
create a separate output which will be triggered based on an if statement to a file, this will be the preferred way of working as it is clear that it is an output.
Depending on the fact if you want to send all data or not, or have it look different or not you might need to use the clone function in order to clone the event into two different ones which can be manipulated apart from each other using tags.
I'm learning how to use logstash and I'm facing some problems in reading a file with logstash which is constantly updated. Here is my test:
logstash.conf
input {
file {
path => ["/usr/share/logs_data/first_log_test.log"]
start_position => "beginning"
}
}
filter {
grok {
match => ["message", "(?<execution_date>\d{4}-\d{2}-\d{2}) (?<execution_time>\d{2}:\d{2}:\d{2})%{GREEDYDATA}ParaBrutos/configs/pipelines/(?<crawler_category>([^/])+)/(?<crawler_subcategory>([^-])+)-(?<crawler_name>([^.])+).json"]
}
}
output {
elasticsearch {
hosts => "elasticsearch:9200"
user => "elastic"
password => "changeme"
ecs_compatibility => disabled
index => "logs_second"
}
}
First, I use this repo's code, for installing ELK stack in a dockerized way.
I started with this test log file empty, and then added few lines that maches the pattern, one by one, in a text editor, simultaneously seeing the index patterns in kibana updating. However, each new row I add in this test log is not added alone, and I see hits of old entries in kibana index patterns.
What happens?
Could it be anything related to not selecting time filters in index pattern creation?
Or something related to since_db settings? But what? Because by default, isn't it supposed to save the last read position of the file?
Or something related to start_position? Even though, by the plugin documentation, it is supposed to make effect only when the first read of the file is done?
I'm a bit lost, tried lots of things and still am not understanding well what's happening. Could you help me?
If you are using a text editor then you are probably creating a new file each time you exit it.
That could be an inode reuse issue. There are links to various issues in the META issue 211. Especially see 251.
Tracking which files have been read when those files can get rotated is an extremely hard problem. Way harder than most folks would initially think. A good option to get it right is to checksum the file contents (although this is not foolproof). The file input does not do that, because it can get ridiculously expensive. Instead it implements a very cheap technique that almost always gets it right (but in a few cases it decides it has already read a file that it has not read).
There are other cases where it gets it wrong by duplicating data (which is what you are hitting). As I said, it is a really hard problem.
I have the following problem to solve:
There is a flat file to read, but the information is unfortunately spread over two rows. So i need to merge these two rows.
I thought about creating an incomplete object first and then add the information from the next row. Then move to the next couple. But i don't really see how to manage that.
Is there a way to read two lines and then process, or to remember an object from one to another step. I'm quite confused.
Any hint would be appreciated. Thanks.
This is a perfect use case for using a SingleItemPeekableItemReader. Check out this older answer for an example.
I have just started log stash, i have log files in that log file whole object is printed in the logs, Since my object is huge i cant write the grok patterns to the whole object and also i expecting only two values out of those object. Can you please let us know how can i get that?
my logs files looks like below
2015-06-10 13:02:57,903 your done OBJ[name:test;loc:blr;country:india,acc:test#abe.com]
This is just an example my object has lot attributes in int , in those object i need to get only name and acc.
Regards
Mohan.
You can use the following pattern for the same
%{GREEDYDATA}\[name:%{WORD:name};%{GREEDYDATA},acc:%{NOTSPACE:account}\]
GREEDYDATA us defined as follows -
GREEDYDATA .*
The key lie in understanding greedydata macro.
It eats up all possible characters as possible.
Logstash patterns don't have to match the entire line. You could also pull the leading information off (date, time, etc) in one grok{} and then use a different grok{} to pull off just the two fields that you want.
I am a novice Go lang programmer,trying to learn Go lang features.I wanted to split a large csv file into multiple files in GO lang, each file containing the header.How do i do this? I have searched everywhere but couldnt get the right solution.Any help in this regard will be greatly appreciated.
Also please suggest me a good book for reference.
Thanking You
Depending on your shell fu this problem might be better suited for common shell utilities but you specifically mentioned go.
Let's think through the problem.
How big is this csv file? Are we talking 100 lines or is it 5G ?
If it's smallish I typically use this:
http://golang.org/pkg/io/ioutil/#ReadFile
However, this package also exists:
http://golang.org/pkg/encoding/csv/
Regardless - let's return to the abstraction of the problem. You have a header (which is the first line) and then the rest of the document.
So what we probably want to do (if ignoring csv for the moment) is to read in our file.
Then we want to split the file body by all the newlines in it.
You can use this to do so:
http://golang.org/pkg/strings/#Split
You didn't mention but do you know how many files you want to split by or would you rather split by the line count or byte count? What's the actual limitation here?
Generally it's not going to be file count but if we pretend it is we simply want to divide our line count by our expected file count to give lines/file.
Now we can take slices of the appropriate size and write the file back out via:
http://golang.org/pkg/io/ioutil/#WriteFile
A trick I use sometime to help think me threw these things is to write down our mission statement.
"I want to split a large csv file into multiple files in go"
Then I start breaking that up into pieces but take the divide/conquer approach - don't try to solve the entire problem in one go - just break it up to where you can think about it.
Also - make gratiutious use of pseudo-code until you can comfortably write the real code itself. Sometimes it helps to just write a short comment inline with how you think the code should flow and then get it down to the smallest portion that you can code and work from there.
By the way - many of the golang.org packages have example links where you can literally run in your browser the example code and cut/paste that to your own local environment.
Also, I know I'll catch some haters with this - but as for books - imo - you are going to learn a lot faster just by trying to get things working rather than reading. Action trumps passivity always. Don't be afraid to fail.
Here is a package that might help. You can set a necessary chunk size in bytes and a file will be split on an appropriate amount of chunks.