Changes for new minimum Solr Versions

This is a list of improvements that can be made to the Solr Operator when it is guaranteed that all Solrs will be at least a certain version.

So when upgrading the minimum supported Solr Version for the operator, we can then go ahead and make all improvements that align with versions <= the new minimum supported version.

8.x

8.0

• SOLR-11126: Used improved healthcheck handler (/solr/admin/health)

8.1

• SOLR-13336: Adding <int name="maxBooleanClauses">${solr.max.booleanClauses:1024}</int> to the default solr.xml.

8.3

• SOLR-13773: Adding SOLR_HEAP, SOLR_JAVA_MEM, GC_TUNE envVar options for the Prometheus Exporter

8.5

• SOLR-14281: Adding <str name="sharedLib">${solr.sharedLib:}</str> to the default solr.xml.

8.6

• SOLR-14561: Adding <str name="allowPaths">${solr.allowPaths:}</str> to the default solr.xml.

8.7

• SOLR-14914: Adding <metrics enabled="${metricsEnabled:true}"/> to the default solr.xml.

8.8

• SOLR-14955: Many of the prometheus exporter options can be set via EnvVars now
• SOLR-14999: Use SOLR_PORT_ADVERTISE for the hostPort information, instead of using a custom option in the solr.xml When we make this upgrade, we will not need to use a custom solr.xml unless the user has specified custom options, such as backup repositories.

8.11

• SOLR-7642: Solr will create a chroot if necessary using the ZK_CREATE_CHROOT envVar

9.x

9.0

• SOLR-14957: Prometheus exporter bin is now in the PATH for the Solr docker image
• SOLR-14957: The default Prometheus exporter config is now on the classpath, and it does not need to be provided on startup.
• SOLR-15914: Solr Modules can be included via an Environment variable, no need to use sharedLib
• SOLR-9575: No need to pre-fill the solr.xml in SOLR_HOME (combined with SOLR-14999)

Future Wishlist

• Have a bin/solr command to healthcheck the Solr Node (possibly split between live and ready). This command would need to support ZKACLs as well as SSL and basicAuth/jwt. (related to SOLR-15199)