Possible, kinda maybe. But then all of the SolrCloud goodness that's there for HA/DR goes out the window because the shared index (actually the hardware it's on) becomes a single point of failure. On the other hand, you're using the word replica but not explicitly talking about SolrCloud, so I guess this is just about standard master/slave situations...
Where the answer is that it's generally not a great idea to share indexes like this. The disk I/O becomes your bottleneck with all those slaves asking to pull what then need off the disk at once, every time it is committed to compounded with network latency. But I have to ask, is this just a theoretical question or is it really something you're having trouble with in production? And the idea of a "replication tree", where N slaves get their index from the master, then M slaves get their index from the first N slaves sounds like a "repeater" setup, see: http://wiki.apache.org/solr/SolrReplication#Setting_up_a_Repeater Best Erick On Wed, Aug 29, 2012 at 4:23 AM, Christian von Wendt-Jensen <christian.sonne.jen...@infopaq.com> wrote: > Hi, > > I was wondering if it was possible to let all replicas of a shard share the > physical lucene files. In that way you would only need one set of files on a > shared storage, and then setup as many replicas as needed without copying > files around. This would make it very fast to optimize and rebalance hardware > resources as more shards are added. > > What I visioning was a setup with one master doing all the indexing. Then all > the shard replicas are installed as a string of slaves setup as both master > and slave, such that the first replica replicates directly from the master. > The next replica replicates from the first replica and so on. > > In this way only the first replica need to write indexfiles. When the next > replica is triggered to replicate it will find that all files are up to date, > and then you issue a "commit" to reload the index in memory, thereby being > up-to-date. The master's commit triggers a cascade of replication, which are > all up-to-date immediately, and then it is a matter of few seconds for the > slaves to be in sync with the master. > > Taking this though further, the first replica could actually access the > master's index files directly, and then be up-to-date without copying any > files. > > Would this setup be possible? > > > > Med venlig hilsen / Best Regards > > Christian von Wendt-Jensen > IT Team Lead, Customer Solutions > > Infopaq International A/S > Kgs. Nytorv 22 > DK-1050 København K > > Phone +45 36 99 00 00 > Mobile +45 31 17 10 07 > Email > christian.sonne.jen...@infopaq.com<mailto:christian.sonne.jen...@infopaq.com> > Web www.infopaq.com<http://www.infopaq.com/> >
