Why does my SSL client fail to connect to Logstash?

The host running Logstash might be unreachable or the certificate may not be valid. To resolve your issue:

Make sure that Logstash is running and you can connect to it. First, try to ping the Logstash host to verify that you can reach it from the host running the Beat. Then use either nc or telnet to make sure that the port is available. For example:
```
ping <hostname or IP>
telnet <hostname or IP> 5044
```
Verify that the certificate is valid and that the hostname and IP match.

For testing purposes only, you can set insecure: true to disable hostname checking.
Make sure that you have enabled SSL (set ssl => true) when configuring the Beats input plugin for Logstash.