Currently I have a ELK stack in which logs are shipped by filebeat and after some filters in logstash, it is forwarded to ES. As there are a lot of servers and logs, a huge logs are coming to logstash, but I have configured the filter to only process a very specific type of log message. Which it is doing fine, but the logs which are not even matching are logged in logstash.log file. As I mentioned earlier that huge logs are coming, the size of logstash.log file is soon reaching to a high value and there is space issue coming up. How to configure the logstash so that I only log the processed logs, and not all.
You could use logrotate to automatically rotate on either a daily basis or once it hits a certain threshold. You could then set the number of rotations to be 1 or 2. This would allow you time to see what is going to the file in case you need to troubleshoot, but purge before it creates space contention.
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I want to be able to track logstash logs in case of an error.
I want to be able to monitor issues when logstash tries to send events to output destination. I've checked the monitor API but it doesn't fulfills my requirements.
Is it a good practice to use file input plugin and set the path to its own log?
I'm currently in front of a structure problem with logstash.
I have a syslog-ng client sending logs from different files through the network to an ELK stack.
I noticed that Logstash is mixing logs, especially multiline with adding exception lines to non error logs from others files. So, i guess the trouble is that my logs are treated without any differentiation from their file origins. I found 2 ways to avoid that, but they are not optimal in my opinion:
Instead of using syslog-ng, use FileBeat and add a tag for each file which identify their origins. Then, parse my log with Logstash depending of this tag. The problem is that using syslog-ng as client is a requirement, and it will bother me if I have to change it
Change my syslog-ng sources to send each log files to a different port on ELK. I found that a little dirty and can be embarrassing with a great quantity of log files
What do you think about that ? Did I miss a better solution?
Is there a way to add a tag just like filebeat in syslog-ng?
I have an existing system that sends me log entries to my server via Syslog protocol. The log entries are written into local files, and then I process these log files with Logstash using its File input plugin.
I like it because even if the Logstash goes down (it happens sometimes), I do not lose any log.
I have just realized today that the Logstash also has a Syslog input plugin that is capable of reading log data on the Syslog protocol.
I am wondering if I turn off my Syslog server, and read the data via the Syslog input plugin of the Logstash, will I have the same reliable system, or If the Logstash goes down, I will lose data during the downtime?
If Logstash goes down you will lose data during the downtime.
Also, the syslog input only works if the messages from your logs are in compliance with the RFC3164, anything different and you will need a grok pattern to parse that message.
If you don't want to use the file input anymore you can create a rule on your syslog server to redirect the messages to your logstash input, in this case, if your logstash goes down, you will still have the files to fill the missing data.
I have been trying this for days but still struggling.
The objective of the script is to perform real time log monitoring on multiple servers (29 in particular) and correlate login failure records between servers. The servers' log will be compressed at 23:59:59 everyday, and a new log starts from 0 o'clock.
My idea was to use tail -f | grep "failed password" | tee centralized_log on every server, activated by a loop through all server names, run on background, and output the login failure records to a centralized log. But it dosn't work. And it creates a lot of daemons which will become zombies as soon as I terminates the script.
I am also considering to do tail at some minutes interval. But as the logs grow larger, the processing time will increase. How to set a pointer to where the previous tail stopped?
So could you please suggest a better and working way to do multiple logs monitoring and correlation. Additional installations are not encouraged unless totally necessary.
If your logs are going through syslog, and you're using rsyslogd, then you can configure the syslog on each machine to forward the specific messages you're interested in to one (or two) centralized log servers, using a property match like:
:msg, contains, "failed password"
See the rsyslog documentation for more details about how to set up reliable syslog forwarding.
I am looking into syslog.
I understand that it is a centralized logging facility that collects logs from various sources.
I have heard that syslog can generate alerts on conditions e.g. max file size of log file is reached.
Is this true?
Because I haven't found how this is done.
Most posts just refer to the logging.
How is the event generation done?
I.e. if I have an app that acts as a log source (redirects logging to a syslog) then is it possible my app can receive an alert, if the max file size has been reached?
How is this configured?
Thank you!
From the application perspective, the syslog function is primarily a receiver of information from the application; the application can write messages to the syslog. There are various bits of information that the application provides to the syslog daemon, including the severity of the message.
The syslog daemon can be configured to take different actions on receipt of different types of message.
No, your application cannot receive an alert when the maximum file size is reached - at least, not via syslog. You might get a SIGXFSZ signal which you can trap. You might prefer to look at your resource limits and keep tabs on your file size to avoid the problem.