Some log missing in elasticsearch

Elastic Stack Elasticsearch
1

I try to transfer logs from filebeat to logstash at time A
The log is located in the filebeat server //filebeatserver/log/LogtoLogstash/*
(including log before time A)

The log is OK starting from time A.
However, it is found i can only receive some logs before time A.
Any idea?

Would that be related to the problem of Filebeat or logstash?
Unfortunately, there are no error found in logstash.plain.log
As there are lots of files...is it related to the max no. of file open?

Problem
Problem1900×176 21.5 KB

2

Although I cannot find any error message from both filebeat and logstash.
I try to resend the logs from filebeat. It is confirmed all logs are OK.
It means it is not the business of filebeat..may be ...the problem is in logstash to handle a large amount of data in a short time. ....just thinking how to notice and prevent that kind of issue.