Commit: Commit itself is a costly process but it becomes more so in Solr-Cloud
because commit requests are propagated to all nodes in the cluster.
Soft Commit: Soft commits make the recently indexed documents available for
search but do not commit to disk. This makes the soft commit less costly but every soft commit opens a new
searcher which in turn rebuilds the cache and runs warm-up queries. If it takes longer to rebuild cache and
run warm-up queries than the interval between soft commits, then even the soft commits will become expensive.
A rule of thumb is "Do not commit after every update". It will just not work!
A good commit frequency could be: Autocommit every 5 seconds or 5000 docs (But this can vary widely based on requirements). solrconfig.xml is often ignored but it has all the settings for commits, warmers and caches.
You must read it and customize it carefully.
Got a thought to share or found a bug in the code? We'd love to hear from you: