### Description Off-heap messages is an Erlang 19 feature:
http://erlang.org/doc/man/erlang.html#process_flag_message_queue_data It is adviseable to use that setting for processes which expect to receive a lot of messages. CouchDB sets it for couch_server, couch_log_server and bunch of others as well. In some cases the off-heap behavior could alter the timing of message receives and expose subtle bugs that have been lurking in the code for years. Or could slightly reduce performance, so a safety measure allow disabling it. ### How to test ``` > config:set("couchdb","enable_off_heap_messages", "false"). > Pid = whereis(couch_server). <0.311.0> > exit(Pid, kill). > erlang:process_info(whereis(couch_server), message_queue_data). {message_queue_data,on_heap} ``` ### Related https://github.com/apache/couchdb/pull/1392 [ Full content available at: https://github.com/apache/couchdb/pull/1597 ] This message was relayed via gitbox.apache.org for [email protected]
