With Elasticsearch 6 (>6.4), we have a warning on index creation :
the default number of shards will change from  to  in 7.0.0
I propose to add number_of_shards in index config.
Also add number_of_replicas that is better explicit.
In case on only one node, it must be 0.
Test plan :
1) Use Elasticsearch
2) Apply patch and flush memcached
3) Rebuild indexes : misc/search_tools/rebuild_elasticsearch.pl -v -b -d
4) Check you dont have a warning about number of shards
5) Check the settings of index :
6) You should see :
"number_of_shards" : "5",
"number_of_replicas" : "1"
Signed-off-by: Victor Grousset/tuxayo <firstname.lastname@example.org>
Signed-off-by: Nick Clemens <email@example.com>
Signed-off-by: Jonathan Druart <firstname.lastname@example.org>