Elastic search server goes unresponsive periodically


I am beginner of elastic search .
My problem regarding elastic search is when i start elastic search after some time elastic search server goes unresponsive, elastic search server is started but no data get fetched and on console following exception occurs:

org.elasticsearch.script.groovy.GroovyScriptExecutionException: IOException[Cannot run program "./tmp/ttyyy": error=2, No such file or directory]; nested: IOException[error=2, No such file or directory];

I am not able to solve it. I always restart elastic search server after 1-2 days or sometime 2-3 time in single day.

Is your ES server accessible to the whole wide Internet? It looks like someone is attempting to exploit it via a Groovy script. Make sure port 9200 and 9300 aren't accessible by those who aren't authorized.

YES ES server is accessible to wide internate. if someone exploit it via a groovy script then is it causes the ES server unresponsive.
server have 8 GB RAM how much -Xms and -Xmx is ideal?

server have 8 GB RAM how much -Xms and -Xmx is ideal?

The standard recommendation is to use half the RAM size as the JVM heap, but never more than 30.5 GB.

This is not good as you are leaving yourself open to attack from the internet. You should use a firewall and any other security measures to protect your cluster from attack. Please read the following blog post and implement it's suggestions to protect your cluster and your data from attack: Scripting and Security | Elastic Blog

thanks magnusbaeck,

we changing our configuration and security of port 9200 and 9300 .
but we still facing the problem of ES server un-Responsive.
Is heap size causese the slowness or unresponsiveness of ES server??