Apache Solr is a standalone enterprise search server with a REST-like API. its an opensource search platform written on Java You put documents in it (called “indexing”) via JSON, XML, CSV or binary over HTTP. You query it via HTTP GET and receive JSON, XML, CSV or binary results.
How to install Solr Apache Server on Ubuntu 18.04 ?
1- Requirements;
Please ensure that Java has been installed, openJDK is Ok, but also you use java from Oracle Install Java
#apt install java
Check Java version Installed
# java -version
openjdk version “11-ea” 2018-09-25
OpenJDK Runtime Environment (build 11-ea+28)
OpenJDK 64-Bit Server VM (build 11-ea+28, mixed mode, sharing)
[root@osrdarFedora ~]#
2-Download and  Install Solr
2.1-Download the compressed file from Solr Apache site
[root@osrdarFedora ~]# wget http://apache.40b.nl/lucene/solr/7.5.0/solr-7.5.0.tgz --2018-11-28 02:37:18-- http://apache.40b.nl/lucene/solr/7.5.0/solr-7.5.0.tgz Resolving apache.40b.nl (apache.40b.nl)... 83.128.155.233 Connecting to apache.40b.nl (apache.40b.nl)|83.128.155.233|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 168429358 (161M) [application/x-gzip] Saving to: ‘solr-7.5.0.tgz’ solr-7.5.0.tgz 100%[==================================================================================================================>] 160.63M 7.30MB/s in 24s 2018-11-28 02:37:44 (6.74 MB/s) - ‘solr-7.5.0.tgz’ saved [168429358/168429358] [root@osrdarFedora ~]#
2.2-Extract and Install The file
[root@osrdarFedora ~]# tar xzf solr-7.5.0.tgz solr-7.5.0/bin/install_solr_service.sh --strip-components=2 [root@osrdarFedora ~]# ls anaconda-ks.cfg install_solr_service.sh original-ks.cfg solr-7.5.0.tgz
[root@osrdarFedora ~]# bash ./install_solr_service.sh solr-7.5.0.tgz id: ‘solr’: no such user Creating new user: solr Extracting solr-7.5.0.tgz to /opt Installing symlink /opt/solr -> /opt/solr-7.5.0 ... 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 *** [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 8444. 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 Waiting up to 180 seconds to see Solr running on port 8983 [/] Started Solr server on port 8983 (pid=28458). Happy searching! Found 1 Solr nodes: Solr process 28458 running on port 8983 INFO - 2018-11-28 02:42:25.929; org.apache.solr.util.configuration.SSLCredentialProviderFactory; Processing SSL Credential Provider chain: env;sysprop { "solr_home":"/var/solr/data", "version":"7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55", "startTime":"2018-11-28T10:41:40.134Z", "uptime":"0 days, 0 hours, 0 minutes, 48 seconds", "memory":"46.9 MB (%9.6) of 490.7 MB"} [root@osrdarFedora ~]#
 3-Manage Solr Service
Please Use the following commands to Start, Stop and check the status of Solr
For Systemd Users – and Systemd users.
sudo systemctl stop solr sudo systemctl start solr sudo systemctl status solr
sudo systemctl enable solr sudo systemctl restart solr sudo systemctl status solr
Firewall  Confuration
The Solr port is 8983. please ensure that the port is running and reachable thru the firewall.
Example 1
Open incoming TCP port 8983 to any source IP address:
$ sudo ufw allow from any to any port 8983 proto tcp
Example 2
Open incoming TCP port 8983 to only specific source IP address eg. 192.168.1.111:
$ sudo ufw allow from 192.168.1.111 to any port 8983 proto tcp
4-Create Collection :
Create your first collection using the following command. you may change the name to something you like.
[root@osrdarFedora ~]# su - solr -c "/opt/solr-7.5.0/bin/solr create -c osradarcol1 -n data_driven_schema_configs" INFO - 2018-11-28 03:50:27.463; org.apache.solr.util.configuration.SSLCredentialProviderFactory; Processing SSL Credential Provider chain: env;sysprop Created new core 'osradarcol1' [root@osrdarFedora ~]#
Step 5 – Solr Web Admin Panel
The access to the Admin panel have no credentials needed. only point your browser to http://ip:8983  or http://host:8983
and Enjoy
Â