Enhancements

• Discovery:
  • Improve handling of multicast binding exceptions #8243 (issue: #8225)
  • Only accept unicast pings when started #7950
• Internal:
  • Use a 1024 byte minimum weight for filter cache entries #8304 (issues: #8249, #8268)
• Logs:
  • Change log level for mpercolate #8306
• Parent/child:
  • Reduce memory usage in top children query #8165 (issue: #8160)

Bug fixes

• Aggregations:
  • Significant terms can throw error on index with deleted docs. #7960 (issue: #7951)
• Allocation:
  • Enable ClusterInfoService by default #8206
• Completion Suggester:
  • Fix CompletionFieldMapper to correctly parse weight #8197 (issue: #8090)
• Geo:
  • Fix IndexedGeoBoundingBoxFilter to not modify the bits of other filters. #8325
• Indexed Scripts/Templates:
  • GetIndexedScript call can deadlock #8266
• Internal:
  • Bind each AllocationDecider as a singleton #8272
  • Add current translog ID to commit meta before closing #8245
  • Cleanup non nested filter to not flip the FixedBitSet returned by the wrapped filter. #8232 (issue: #8227)
  • Dynamic changes to max_merge_count are now picked up by index throttling #8136 (issue: #8132)
  • Only schedule another refresh if refresh_interval is positive #8087 (issue: #8085)
  • Make version parsing more lenient #8076
  • Add all unsafe variants of LZF compress library functions to forbidden APIs. #7468 (issue: #8078)
• Mapping:
  • Throw exception if null_value is set to null #7978 (issue: #7273)
• Parent/child:
  • Check if there is a search context, otherwise throw a query parse exception. #8177 (issue: #8031)
  • has_parent filter must take parent filter into account when executing the inner query/filter #8020 (issue: #7362)
• Recovery:
  • mapping check during phase2 should be done in cluster state update task #7744
• Resiliency:
  • Don't catch FNF/NSF exception when reading metadata #8207
• Scripting:
  • Clear the GroovyClassLoader cache before compiling #8062 (issues: #7658, #8073)
• Search:
  • Passing fieddata_fields as a non array causes OOM #8203
• Snapshot/Restore:
  • Fix snapshotting of a single closed index #8047 (issue: #8046)
  • Make it possible to delete snapshots with missing metadata file #7981 (issue: #7980)
• Sorting:
  • Use first non-empty result to detect if sort is required #8236 (issue: #8226)