Updated March 15, 2023
Introduction to Logstash Date Filter
The logstash date filter is defined as a filter in the logstash that can be utilized for analyzing the dates from fields, and after that, it has been used for the events, which are the timestamps in the logstash. If the date filter is not present in the event, then the logstash can select the timestamp that has been established at the first time means at the time of providing input and when the timestamp is not already put on in the event. It can use syntax for parsing date and time as a letter for specifying the type of time value.
What is the logstash date filter?
The date filter can be used to analyze the dates in the fields with the help of the format, and that date will be used for giving the current time of the event, which are defined in the time library, and what we need that all have been used to specify the field. So it can also confirm the format used, and as per the content of the field, the logstash can timestamp the event. If the field does not exist, it cannot update the event. So we can say that logstash is the best option for parsing or analyzing the dates as events. We can also utilize this filter for exercising the historical data; mostly, the date filters have been used for sorting the events and bringing in the old data.
How to use the logstash date filter?
The date filter has been utilized to analyze the dates from the fields of the event; after that, the dates that we get have been used as the timestamp of logstash in the event.
Let us see an example in which the Syslog may have a timestamp as
“May 15 08:41:02”
It has a date format for parsing as MMM dd HH:mm: ss.
Mainly the format has been used for sorting events and also for populating the previous data, in the case in our event if we did not get an accurate date, then penetrating the date can be sorted out of order, and let us see another condition that if the filter is not present then, logstash can able to select a timestamp which can also depend on the date which we are providing at the first time or at the input time. So it means for the time as an input, the timestamp has been set to the time for every read; one thing which we need to keep in mind is that if we try to parse two dates, then we have to use the same pattern for a date in which we can use a separator for the colon.
When we try to use the date filter, then we need to describe the time zone canonical ID which has been utilized for parsing the date in which the valid ID will be useful if we do not have to extract the value from the time zone and that will do have the default platform, if we do not need to describe the platform when the default platform will be in use then canonical ID will be the good option to save our time. It can use the letter type syntax for parsing the date and time text for describing the month, minute, kind of time value, and if we want to use the 2-digit month or full month name, then it can allow using the repetition of letters for specifying the time value.
Logstash date filter configuration
Although the logstash is the best for analyzing events as they happen, we can able to utilize it for proceeding the historical data, in which the logstash can able to timestamp the event along the time when the event which has been processed at the first time which cannot be good for parsing the historic data, the logstash will give the logstash date filter to support the analyzing and setting of the dates and timestamp.
- In a short statement, the date filter can analyze the dates with the help of the format which can be defined in the time library, all the information which we need to describe in the fields and the format it can conform and it can able to use the timestamp for the event as per the content of that field, if the field does not present, or it cannot be populated then we cannot be able to update the event.
For example,
filter
{
date
{
match => [ "getdate", "yyyy-MM-dd HH:mm:ss" ]
}
}
Such type of timestamp will be able to use the event if the event ‘getdate’ has the field the date which we get that will see like 2016-03-13 15:16:17.
- In a similar way, let us see it with the help of a long statement; if we try to analyze the date which does not have the timezone, then we can able to use the timezone setting for describing the default time zone for the event in which we can able to use the time zone ID as given below,
filter
{
date
{
match => [ "getdate", "yyyy-MM-dd HH:mm:ss" ]
timezone => "America/Johannesburg"
}
}
The month and weekdays may be defined in various locales, so we can use the ‘locale’ setting to make sure that we are analyzing it in the proper format, and we can use the setting which has the country and variant section, which can be optional.
- For easier analyzing of dates, the logstash can have the ‘match’ parameter,
filter
{
date
{
match => [ "getdate", "yyyy-MM-dd HH:mm:ss" ]
locale => "Eng_US_POSIX"
}
}
Conclusion
In this article, we conclude that the date filter has been used for parsing the dates from fields, we have also discussed how to use the date filter, and we have seen the configuration of that, which can help us understand the concept of date filter in the logstash.
Recommended Articles
This is a guide to Logstash Date Filter. Here we discuss the Introduction, What is a logstash date filter, How to use a logstash date filter? Examples, code. You may also have a look at the following articles to learn more –
