I have struggled a bit with the installation itself, due to incorrectly configuring the IP addresses, an internal IP address with it’s corresponding NAT for public availability; the instance is running on Amazon AWS. After that issue was finally resolved, I have noticed in the logs the following error,
2019-06-06T12:09:07.094Z WARN [ProxiedResource] Unable to call http://public_ip_address:9000/api/system/metrics/multiple on node <node_id> java.net.SocketTimeoutException: connect timed out
I have tried Googling a bit around and followed a few troubleshooting steps, which led me to start testing with cURL, whether I could access the aforementioned API URL. That was not possible from the instance itself, but it was working properly from my laptop, which I was using for remotely managing the Graylog server. The issue was the access list on Amazon AWS, not allowing the instance itself to reach its own public IP address, so I have adjusted the access list, allowed all traffic and the issue was resolved; the error disappeared from the logs.
Back to the cURL testing using the command,
curl -i ‘http://public_ip_address:9000/api/?pretty=true’
I was getting the following,
HTTP/1.1 307 Temporary Redirect
Date: Thu, 06 Jun 2019 13:07:19 GMT
After Googling again, someone suggested to use the -L option which essentially follows the redirects and that has resolved the issue, adjusting the command to curl -iL instead.
Apologies for the long text, I would like to know first, why I need the -L option while others can get the same output without it, as well as a brief explanation as to what it actually does.
Thank you in advance.