Change the default delayed allocation timeout from 0 (no delayed allocation) to 1m. The value came from a test of having a node with 50 shards being indexed into (so beefy translog requiring flush on shutdown), then shutting it down and starting it back up and waiting for it to join the cluster. This took, on a slow machine, about 30s.
The value is conservatively low and does not try to address a virtual machine / OS restart for now, in order to not have the affect of node going away and users being concerned that shards are not being allocated to the rest of the cluster as a result of that. The setting can always be changed in order to increase the delayed allocation if needed.
closes#12166
Clinton Gormley
Shay Banon