http 500, 'timeout / couch_config, delete "oauth_token_secrets"'

Binary package hint: couchdb

it caused HTTP 500 and couchdb described it as
{"error":"timeout","reason":"{gen_server,call,\n [couch_config,\n {delete,\"oauth_token_secrets\",\"(cleaned)\",true}]}"}
{gen_server,call,2},
             {couch_httpd_auth,get_user,2},
             {couch_httpd_auth,create_user_req,2},
             {couch_httpd,handle_request,5},
             {mochiweb_http,headers,5},
             {proc_lib,init_p_do_apply,3}