Change the recovery settings names to a better descriptive names (they are not on shard level), from index.shard.recovery to indices.recovery prefix, and allow to change all using cluster update settings API. The settings are: indices.recovery.file_chunk_size, indices.recovery.translog_ops, indices.recovery.translog_size, indices.recovery.compress, indices.recovery.concurrent_streams.
Recovery Settings: Change settings (still support old settings) and a…
…llow for more dynamic settings, closes #1303.
The page http://www.elasticsearch.org/guide/reference/index-modules/translog.html mention some defaults for index.translog.flush_threshold_size and index.translog.flush_threshold_ops
Those are the same as indices.recovery.translog_ops and indices.recovery.translog_size ??
If so, then why when ES starts I see smaller values : translog_size [100kb], translog_ops 
From my log:
[2011-12-07 14:44:56,098][DEBUG][index.shard.recovery ] [De La Fontaine, Valentina Allegra] using concurrent_streams , file_chunk_size [100kb], translog_size [100kb], translog_ops , and compress [true]
@aguereca which version are you using? it will print it under indices.recovery. The settings you pointed to in translog index module control when its being flushed, while the these settings control how its being recovered.
@kimchy Thanks, I just update to the last version, now is printing under indices.recovery. Thanks for the clarification, now is clear to me the difference on both, I stumble with those settings because I'm trying to track a pesky error: "this writer hit an OutOfMemoryError; cannot commit" that have been happening "randomly" each few days on one of the indexes, and one of the messages that I found in the log after some "failed engine" and before the "Flush failed" was a : "failed to flush shard on translog threshold", so I was wondering is some tweaking of this settings could make the trick.