Solr's installation directory structure:

• Solr root directory ("${SOLR_ROOT}") contains the following directories and files:
  
  $ tree -L 1 /opt/solr /opt/solr ├── bin: utility scripts ├── server: solr server home directory ├── dist: Solr libraries: core, solrj, test-framework, contrib modules ├── contrib: contrib modules ├── example: Solr examples ├── docs: link to Solr Documentation ├── licenses ├── LICENSE.txt ├── NOTICE.txt ├── README.txt ├── LUCENE_CHANGES.txt └── CHANGES.txt
  
• Solr "${SOLR_ROOT}/bin" directory contains the following directories and files:
  
  $ tree -L 1 /opt/solr/bin /opt/solr/bin ├── solr: Solr command line (start, stop, ...) ├── solr.in.sh: Solr settings ├── post: Solr command line to post files ├── postlogs: Solr command line to post logs files ├── oom_solr.sh: kill Solr process ├── install_solr_service.sh: install Solr service └── init.d
  
• The "server" directory contains the files required to run Solr as a server process.
  
  - The "contexts" directory contains the configuration file for the Jetty's WebApp.
  - The "etc" directory contains the configuration files of Jetty (jetty host, port, ...).
  - The "resources" directory contains log4j configuration files (Log debugging levels can be changed at runtime in the Solr Admin UI).
  - The "solr" directory contains solr configuration files (solr.xml, zoo.cfg) and solr config examples (configsets).
  - The "solr-webapp" directory contains the Solr web application files.
  - The "logs" directory contains log files (server, jvm metrics, slow requests).
  
  Solr "${SOLR_ROOT}/server" directory contains the following directories and files:
  
  $ tree -L 1 /opt/solr/server /opt/solr/server ├── solr: default Solr home directory (index files, configuration files, configsets samples) ├── logs: logs files ├── resources: logs configuration files ├── scripts: SolrCloud scripts (zkcli.sh, snapshotscli.sh) ├── solr-webapp: Solr webapp ├── lib: Jetty libraries ├── contexts: Jetty webapp deployment descriptor file ├── etc: Jetty configuration files ├── start.jar └── README.txt
  
• Solr "${SOLR_ROOT}/server/solr" default home directory contains the following directories and files:
  
  $ tree -L 1 /opt/solr/server/solr /opt/solr/server/solr ├── solr.xml: Solr configuration file ├── zoo.cfg: Zookeeper (embedded) configuration file ├── configsets: Solr configuration examples (_default, sample_techproducts_configs) └── README.txt
  
• The "contrib" directory contains extensions modules to Solr.
  
  - The DataImportHandler (DIH) module allows importing data from databases, XML files, and HTTP data sources.
  - The Extraction (Solr Cell) module allows extraction text from files (pdf, word, ...) by leveraging Apache Tika.
  
  Solr "${SOLR_ROOT}/contrib" directory contains the following directories and files:
  
  $ tree -L 1 /opt/solr/contrib /opt/solr/contrib ├── extraction: Tika support for text extraction ├── analysis-extras: text analysis plugins ├── clustering: clustering support for search results ├── langid: language detection └── velocity: velocity templates-based UI
  
• Solr "${SOLR_ROOT}/example" directory contains the following directories and files:
  
  $ tree -L 1 /opt/solr/example /opt/solr/example ├── example-DIH: DataImportHandler configuration files ├── files: file-based search configuration files ├── exampledocs: sample documents ├── films: sample film data (json, csv, xml) └── README.txt
  
• The "dist" directory contains libraries jar files.
  
  - Solr core jar file is needed to create Java based clients application that uses Solr features.
  - SolrJ jar file and solrj-lib directory are needed to create Java based clients application that integrate with Solr.
  - Solr test framework jar file and test-framework directory are needed to create unit and integration tests for Solr.
  
  Solr "${SOLR_ROOT}/dist" directory contains the following directories and files:
  
  $ tree -L 1 /opt/solr/dist /opt/solr/dist ├── solr-analysis-extras-8.6.0.jar ├── solr-analytics-8.6.0.jar ├── solr-cell-8.6.0.jar ├── solr-clustering-8.6.0.jar ├── solr-core-8.6.0.jar ├── solr-dataimporthandler-8.6.0.jar ├── solr-dataimporthandler-extras-8.6.0.jar ├── solr-jaegertracer-configurator-8.6.0.jar ├── solrj-lib ├── solr-langid-8.6.0.jar ├── solr-ltr-8.6.0.jar ├── solr-prometheus-exporter-8.6.0.jar ├── solr-solrj-8.6.0.jar ├── solr-test-framework-8.6.0.jar ├── solr-velocity-8.6.0.jar └── test-framework