Logstash losing the logs

I think my logstash eating the logs, I am not sure, where I am making the mistake. I am using logstash 2.4, elasticsearch 2.4.1, kibana 4.6.1.
I am not an expert in ELK, but started to explore it. Many times I noticed and felt that logstash losing the logs. so I made a test setup to confirm and test this.

I have a elasticsearch server which is 8 core, 64GB ram, 3.2TB HDD in RAID (15k rpm) running on Centos 7 64bit and Kibana also running in the same server.

I have a seperate server in the same subnet, and connected in the same switch. This server is only for logstash - 16 core, 28gb ram, 600gb hdd. (HP DL 580 G4) running Centos 7 64bit.

Now from my windows workstation I used kiwi syslog message generator to generate 500 syslog messages towards logstash server. Done. :slight_smile:
when I look the kibana I can see only 325 logs, I did the testing couple of times, everytime I can see 280 or 325 or 340 or 375, Its varying between 250 to less than 400.

I did a tcpdump during the test, I can see all the 500 logs arrived to the server perfectly. So there is no way for network related issue or packet loss during the transit.

I am not sure what I am missing, Can anyone shed some lights on this?

I am having a similar issue. Please let me know if you figure out a solution.

I changed the batch size to 5000, it improved little bit, but losses was there and I used kafka as a memory broker, and looks fine now.

how are you sending logs to logstash? are you using syslog to a file and monitoring the file with logstash or are you using winlogbeat? posting more information on your setup could help us help you. Posting your logstash configuration and several lines of your logs can also help. I cannot even guess at your issue with the little info provided.

-why a penny