Akitogo Team, 20 Sep 2018
If you start Solr 7
sudo /etc/init.d/solr restart on a newly installed Ubuntu you might see the following messages:
*** [WARN] *** Your open file limit is currently 1024. It should be set to 65000 to avoid operational disruption. If you no longer wish to see this warning, set SOLR_ULIMIT_CHECKS to false in your profile or solr.in.sh *** [WARN] *** Your Max Processes Limit is currently 31668. It should be set to 65000 to avoid operational disruption. If you no longer wish to see this warning, set SOLR_ULIMIT_CHECKS to false in your profile or solr.in.sh Sending stop command to Solr running on port 8983 ... waiting up to 180 seconds to allow Jetty process 1505 to stop gracefully. Warning: Available entropy is low. As a result, use of the UUIDField, SSL, or any other features that require RNG might not work properly. To check for the amount of available entropy, use 'cat /proc/sys/kernel/random/entropy_avail'.
How to get rid of these warnings?
Open file limit and max processes limit
sudo vi /etc/security/limits.conf
Add to file:
solr hard nofile 65535
solr soft nofile 65535
solr hard nproc 65535
solr soft nproc 65535
solr with the username solr is running under
Fix available entropy
sudo apt-get -y install rng-tools
sudo vi /etc/default/rng-tools
Add at bottom of file:
Save your changes and:
sudo /etc/init.d/rng-tools restart
Restart solr and you shouldn't see any warnings.