question Re: NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover? in Support Questions

NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover?

Eric_B — Tue, 31 May 2022 19:30:57 GMT

Version: NiFi 1.11.x

Noticed a behavior where for this version of NiFi, when the remote url is a GSLB, it doesn't recognize when a host is removed from a GSLB until the processor is stopped. Any idea why? Any ideas for a solution?

Re: NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover?

Eric_B — Fri, 17 Jun 2022 16:13:22 GMT

Kind of an update: A jank workaround was to force the Connection to close, but it's not the best solution. Looking to see why the client is ignoring the DNS TTL.

Re: NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover?

araujo — Sat, 25 Jun 2022 05:47:35 GMT

@Eric_B ,

This is a behaviour inherited from Java. Java caches DNS resolved names internally.

You can adjust the cache TTL value by specifying the corresponding Java property during NiFi startup.

Please see a description of the property here: https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/java-dg-jvm-ttl.html

Cheers,

André

Re: NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover?

Eric_B — Tue, 27 Sep 2022 17:16:55 GMT

Hi @araujo ! That seems to be cause, but I'm a bit confused on how I would set it up. I attempted to both set it in the bootstrap as well as via the jre, but still nothing seems to be working.

Re: NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover?

araujo — Wed, 28 Sep 2022 07:18:49 GMT

Can you share your settings?

Re: NiFi InvokeHTTP -Is there DNS caching or something that would interfere with GSLB failover?

Eric_B — Tue, 11 Oct 2022 18:34:36 GMT

I've attempt to set the above in the java.security file and in the bootstrap I set the runtime variables as
java.arg.20=-Djava.security.networkaddress.cache.ttl=60
java.arg.21=-Dsun.net.inetaddr.ttl=60