Apache nifi Distributed map cache client service giving error

[#1]

I am using the utility of wait and notify and for that I have used Distributed map cache client service and Distributed map cache server, but somehow I am getting an error in service "too many open files", I have even increased the "nofile" in node. In the same instance but in another nifi flow I am able to use this functionality but if I do configure this service in another parallel flow I face issues. Below I am attaching the screenshot of conf and error. any help would be appreciated.

[#2]

@Mridul_garg 
Sharing the complete stack trace(s) from the nifi-app.log maybe be helpful in helping you here.
When you say you changed the open file limits, what ddi you change it to?
what does the output from "ulimit -a" show.  Make sure you run this command as the same user that owns your NiFi process.

Thanks,
Matt