问题
How to upgrade Apache solr from existing version 4.10.4 to 6.6.0 (A latest one) On linux centos 7 operating system.
回答1:
stop existing running solr
sudo service solr stop
confirm its stopped or not
sudo service solr status
You can take backup of existing solr data from /var/solr/data/< core_name >, But reindexing solr data after upgrading solr version will give best performance without any unknown issues.
now remove existing solr from centos
sudo rm -r /var/solr
remove solr from following location if its there
sudo rm -r /opt/solr
sudo rm /etc/init.d/solr
In my case following path was not exist to delete, Delete if exists in your case
sudo rm -r /opt/solr/solr-4.10.4
remove existing solr user with home directory
sudo userdel -r solr
for ubuntu
sudo deluser --remove-home solr
remove existing group
sudo groupdel solr
for ubuntu
sudo deluser --group solr
restart your system
sudo reboot
Check supporting application and download solr 6.6
Check which version Java version is installed on your machine
java -version
Check available java versions, and update to latest version
yum list available java*
Install latest java version
sudo yum install <jdk version>
download and extract installation folder
mkdir /home/user/temp
cd temp
wget http://apache.org/dist/lucene/solr/6.6.0/solr-6.6.0.tgz
tar -zxvf solr-6.6.0.tgz
install solr
cd solr-6.6.0/
sudo bin/install_solr_service.sh /home/user/temp/solr-6.6.0.tgz
after successful installation you can see following output
id: solr: no such user Creating new user: solr
Extracting /home/user/temp/solr-6.6.0.tgz to /opt
Installing symlink /opt/solr -> /opt/solr-6.6.0 ...
Installing /etc/init.d/solr script ...
Installing /etc/default/solr.in.sh ...
Service solr installed. Customize Solr startup configuration in /etc/default/solr.in.sh Waiting up to 180 seconds to see Solr running on port 8983 [] Started Solr server on port 8983 (pid=4802). Happy searching!
Found 1 Solr nodes:Solr process 4802 running on port 8983 {
"solr_home":"/var/solr/data", "version":"6.6.0 5c7a7b65d2aa7ce5ec96458315c661a18b320241 - ishan - 2017-05-30 07:32:53", "startTime":"2017-06-26T07:02:51.523Z", "uptime":"0 days, 0 hours, 0 minutes, 13 seconds", "memory":"34.4 MB (%7) of 490.7 MB"}
Now check if you can access solr admin panel
http://localhost:8983/solr/
Check if solr is running, start solr if not running and then try
sudo service solr status
If you are still not able to access solr admin panel, then may you OS firewall is blocking to port 8983
use following commands to allow port 8983 in firewall
sudo firewall-cmd --zone = public --add-port = 8983 / tcp --permanent
sudo firewall-cmd --reload
For further data migration please see Migration of solr cores after solr version upgradation from 4.10.4 to 6.6.0 on Cent os 7
来源：https://stackoverflow.com/questions/44755868/upgrade-apache-solr-from-4-10-4-to-6-6-0-on-cent-os-7