@Eslam
Welcome to the community.
In order to get helpful answers, you'll need to provide more detail around your use case.
NiFi provides many processors for connecting to various services on external hosts.
You can find the list of default processors available with the Apache NiFi release here:
NiFi 1.x release:
https://nifi.apache.org/docs/nifi-docs/
NiFi 2.x release:
https://nifi.apache.org/components/
At the very basic of level you have processors like:
But there are also processor for connecting SMB, Splunk, rest-apis, SNMP, FTP, DBs, Kafka, hive, etc. on external servers.
Look through the components list in the documentation for Get, List, Fetch, and Query type processors to see if any of them meet your use case needs.
Please help our community thrive. If you found any of the suggestions/solutions provided helped you with solving your issue or answering your question, please take a moment to login and click "Accept as Solution" on one or more of them that helped.
Thank you,
Matt