[Solr Wiki] Update of "MultiCore" by ryan

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The following page has been changed by ryan:
http://wiki.apache.org/solr/MultiCore

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  <!> ["Solr1.3"]
  
- [[TableOfContents]]
+ See: CoreAdmin
  
- = Overview =
+ In solr, the "multi core" concept refers to the ability to have multiple cores running in the same webapp.
  
- Solr allows multiple SolrCore instances to run within a single web-app.  The cores 
- can be dynamically managed via the MultiCoreHandler.  For alternative ways to manage multiple indecies, see MultipleIndexes.
- 
- = Configuration =
- 
- To enable multi core support, place a file named ''solr.xml'' in the solr.home 
- directory.  Here is an example ''solr.xml'' file:
- {{{
- <solr persistent="true" sharedLib="lib">
-  <cores adminPath="/admin/multicore">
-   <core name="core0" instanceDir="core0" />
-   <core name="core1" instanceDir="core1" />
-  </cores>
- </solr>
- }}}
- 
- == solr ==
- The `<solr>` tag accepts two attributes:
-   *'''persistent''' - By default, should runtime core manipulation be saved in ''solr.xml'' so that it is available after a restart.
-   *'''sharedLib''' - Path to a directory containing .jar files that are added to the classpath of every core.  The path is relative to solr.home (where solr.xml sits)
- 
- == cores ==
- The `<cores>` tag accepts one attribute:
-   *'''adminPath''' - RequestHandler path to access the !MultiCoreHandler for dynamic core manipulation.  For example, adminPath="/admin/multicore" configures access via http://localhost:8983/solr/admin/multicore.  If this attribute is not specified, dynamic manipulation is unavailable.
- 
- == core ==
- The `<core>` tag accepts two attributes:
-   *'''name''' - The registered core name.  This will be how the core is accessed.
-   *'''instanceDir''' - The ''solr.home'' directory for a given core.
- 
- = Example =
- 
- Solr ships with an example multicore setup.  To run this configuration, start jetty using:
- {{{
- java -Dsolr.solr.home=multicore -jar start.jar
- }}}
- 
- This will start solr running two cores: ''core0'', and ''core1''.  To access each core, try:
-  http://localhost:8983/solr/core0/select?q=*:*
-  
-  http://localhost:8983/solr/core1/select?q=*:*
- 
- 
- To access the admin pages for each core visit:
-  http://localhost:8983/solr/core0/admin/
-  
-  http://localhost:8983/solr/core1/admin/
- 
- 
- = MultiCoreHandler =
- 
- The !MultiCoreHandler is a special SolrRequestHandler that is used to manage existing cores.
- Unlike normal !SolrRequestHandlers, the !MultiCoreHandler is not attached to a core,
- it is configured in solr.xml.  A single MultiCoreHandler exists for each web-app
- 
- To enable dynamic core configuration, make sure the ''adminPath'' attribute is set in
- solr.xml.  If this attribute is absent, the !MultiCoreHandler will not be available.
- 
- 
- == STATUS ==
- 
- Get the status for a given core or all cores if no core is specified:
- 
-  http://localhost:8983/solr/admin/multicore?action=STATUS&core=core0
-  
-  http://localhost:8983/solr/admin/multicore?action=STATUS
- 
- == CREATE ==
- 
- Creates a new core and register it.
- If persistence is enabled (persist=true), the configuration for this new core will be saved in 'multicore.xml'.
- If a core with the same name exists, while the "new" created core is initalizing, the "old" one will continue to accept requests.  Once
- it has finished, all new request will go to the "new" core, and the "old" core will be unloaded.
- 
-  http://localhost:8983/solr/admin/multicore?action=CREATE&name=coreX&instanceDir=path_to_instance_directory&config=config_file_name.xml&schema=schem_file_name.xml
- 
- Note that config & schema parameters are optional.
- 
- == LOAD ==
- 
- /!\ '''not implemented yet!'''
- 
- This will load a new core from an existing configuration (will be implemented when cores can be described with a lazy-load flag).
- 
- ?persist=true will save the changes to solr.xml
- 
-   http://localhost:8983/solr/admin/multicore?action=LOAD&core=core0
- 
- == UNLOAD ==
- 
- /!\ '''not implemented yet!'''
- 
- Remove a core from solr.  Existing requests will continue to be processed, but no new
- requests can be sent to this core.
- 
-   http://localhost:8983/solr/admin/multicore?action=UNLOAD&core=core0
- 
- 
- == RELOAD ==
- 
- Load a new core from the same configuration as an existing registered core.  While the 
- "new" core is initalizing, the "old" one will continue to accept requests.  Once
- it has finished, all new request will go to the "new" core, and the "old" core will
- be unloaded.
- 
-   http://localhost:8983/solr/admin/multicore?action=RELOAD&core=core0
- 
- 
- == SWAP ==
- 
- Change the names used to access a core
- 
-   http://localhost:8983/solr/admin/multicore?action=SWAP&core=core1&with=core0
- 
- ---------
- 
- See [https://issues.apache.org/jira/browse/SOLR-215 SOLR-215] and [https://issues.apache.org/jira/browse/SOLR-350 SOLR-350]
-