[
https://issues.apache.org/jira/browse/NIFI-10221?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
David Handermann updated NIFI-10221:
------------------------------------
Issue Type: Improvement (was: Bug)
> Nifi does not respect multirecord domain in hostname field.
> -----------------------------------------------------------
>
> Key: NIFI-10221
> URL: https://issues.apache.org/jira/browse/NIFI-10221
> Project: Apache NiFi
> Issue Type: Improvement
> Affects Versions: 1.16.0
> Reporter: Wiktor Kubicki
> Assignee: David Handermann
> Priority: Major
>
> *Short description:*
> Using DNS we are able to add multiple A records with several IP addresses to
> domain, but Nifi use always only (first?) one.
>
> *Background:*
> We can add multiple A records in DNS to provide round robin "load balancer",
> which can also be used as failover server in Active - Active server schema. A
> good example of that implementation is there: [How To Configure DNS
> Round-Robin Load-Balancing For High-Availability |
> DigitalOcean|https://www.digitalocean.com/community/tutorials/how-to-configure-dns-round-robin-load-balancing-for-high-availability].
> We use this solution to provide address to our two sFTP servers in different
> geographical locations.
>
> {*}How it works now{*}:
> When i put domain into hostname field in listSFTP, Nifi will solve DNS and
> obtain only one address (probably the first one but i cannot comfirm) and
> connect to it. But when this one IP is unreachable, NiFi will not try with
> second one nor try the second one in any next run.
>
> *How it should works:*
> Addresses should be used randomly (round robin), and if one is unavailable,
> then in the same run should be tried another one till end of IP's or
> successful connection.
>
> {*}Example{*}:
> Using sftp client (OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017) i can
> connect to host by domain, even if one of IP addresses is down:
>
> {code:java}
> $ sftp -vvv -oPort=22 u...@example.com
> OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017
> debug1: Reading configuration data /XXX/.ssh/config
> debug1: Reading configuration data /etc/ssh/ssh_config
> debug1: /etc/ssh/ssh_config line 58: Applying options for *
> debug2: resolving "example.com" port 22
> debug2: ssh_connect_direct: needpriv 0
> debug1: Connecting to example.com [X.X.X.203] port 22.
> debug1: connect to address X.X.X.203 port 22: Connection refused
> debug1: Connecting to example.com [Y.Y.Y.123] port 22.
> debug1: Connection established.{code}
> As you can see, sftp tries to connect to first, when connections refused then
> it try to second one with success. And that's how it should work in NiFi
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
