: This comment for the benefit of who is using distributed search: : The protocol of communication has been xml for distributed search. For : a good part of 1.3. : It is now changed to a custom binary format (SOLR-486 ). So each shard : participating in a distributed search must be using the same protocol. : Safest thing is to install each shard with same binaries.
presumably the binary format includes a header with version info, so future enhancements to the format can be backwards compatible, correct? (the same way new versions of Lucene can open indexes created by older versions) it would really suck if the only way to upgrade a distributed search cluster in the future was to take the whole cluster offline an upgrade them all at once ... we want to make sure that in the future people upgrading from 1.3 to 1.X can bring up a new "aggregator" running 1.X, but pointing at all the same shards (running 1.3) and then upgrade the individual shards one at a time. (either that, or the aggregator needs to specify the max format "version" it can handle when querying the shards, and then the shards could be upgraded first) -Hoss
