This document discusses reindexing large repositories in Alfresco. It covers the Alfresco SOLR architecture, the indexing process, scenarios that require reindexing, alternatives for deployment during reindexing to minimize downtime, monitoring and profiling tools, and future improvements planned for Search Services 2.0 to optimize indexing performance. Benchmark results are presented showing improvements that reduced reindexing time for 1.2 billion documents from 21 days to 10 days.