More than you want to know about hard and soft commits here: https://lucidworks.com/2013/08/23/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
You don't need to read it though, Emir did an admirable job of telling you why turning off hard commits is a terrible idea. Best, Erick On Fri, Sep 29, 2017 at 1:07 AM, Emir Arnautović <emir.arnauto...@sematext.com> wrote: > Hi Wei, > Hard commits are about data durability. It will roll over transaction logs > and create index new index segment. If configured with openSearcher=false, > they do not affect query performance much (other then taking some resources) > since they do not invalidate caches. If you have transaction logs enabled, > without hard commits it would grow infinitely and can result in full disk. In > case of heavy indexing, even rare hard commits can result in large > transaction logs causing Solr restart after crash to take a while because > transaction logs are replayed. > Soft commits are the one that are affecting query performance and should be > as rare as your requirements allow. They invalidate caches causing cold > searches or if you have warming set up, take resources to do the warming. > > I would recommend to keep hard commits, set to every 20-60 seconds (depending > on indexing volume) and make sure openSearcher is set to false. > > HTH, > Emir > >> On 29 Sep 2017, at 06:55, Wei <weiwan...@gmail.com> wrote: >> >> Hello All, >> >> What are the impacts if solr cloud is configured to have only soft commits >> but no hard commits? In this way if a non-leader node crashes, will it >> still be able to recover from the leader? Basically we are wondering in a >> read heavy & write heavy scenario, whether taking hard commit out could >> help to improve query performance and what are the consequences. >> >> Thanks, >> Wei >
