Thanks Erick. Can you explain a bit more on the write.lock file? So far I have been copying it over from B to A and haven't seen issue starting the replica.
On Sat, Aug 26, 2017 at 9:25 AM, Erick Erickson <erickerick...@gmail.com> wrote: > Approach 2 is sufficient. You do have to insure that you don't copy > over the write.lock file however as you may not be able to start > replicas if that's there. > > There's a relatively little-known third option. You an (ab)use the > replication API "fetchindex" command, see: > https://cwiki.apache.org/confluence/display/solr/Index+Replication to > pull the index from Cloud B to replicas on Cloud A. That has the > advantage of working even if you are actively indexing to Cloud B. > NOTE: currently you cannot _query_ CloudA (the target) while the > fetchindex is going on, but I doubt you really care since you were > talking about having Cloud A offline anyway. So for each replica you > fetch to you'll send the fetchindex command directly to the replica on > Cloud A and the "masterURL" will be the corresponding replica on Cloud > B. > > Finally, what I'd really do is _only_ have one replica for each shard > on Cloud A active and fetch to _that_ replica. I'd also delete the > data dir on all the other replicas for the shard on Cloud A. Then as > you bring the additional replicas up they'll do a full synch from the > leader. > > FWIW, > Erick > > On Fri, Aug 25, 2017 at 6:53 PM, Wei <weiwan...@gmail.com> wrote: > > Hi, > > > > In our set up there are two solr clouds: > > > > Cloud A: production cloud serves both writes and reads > > > > Cloud B: back up cloud serves only writes > > > > Cloud A and B have the same shard configuration. > > > > Write requests are sent to both cloud A and B. In certain circumstances > > when Cloud A's update lags behind, we want to bulk copy the binary index > > from B to A. > > > > We have tried two approaches: > > > > Approach 1. > > For cloud A: > > a. delete collection to wipe out everything > > b. create new collection (data is empty now) > > c. shut down solr server > > d. copy binary index from cloud B to corresponding shard replicas > in > > cloud A > > e. start solr server > > > > Approach 2. > > For cloud A: > > a. shut down solr server > > b. remove the whole 'data' folder under index/ in each replica > > c. copy binary index from cloud B to corresponding shard replicas > in > > cloud A > > d. start solr server > > > > Is approach 2 sufficient? I am wondering if delete/recreate collection > > each time is necessary to get cloud into a "clean" state for copy binary > > index between solr clouds. > > > > Thanks for your advice! >
