我在 rhohub 上有一个 rhosync 应用程序。通常它可以正常工作，但间歇性地我会收到此错误。当我重新启动服务器时，它又可以正常工作了。
我试图在代码中找到递归，但无法做到。以下是日志：
2012-07-14T10:52:27+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/runner.rb:143:in `run!'
2012-07-14T10:52:27+00:00 app[web.1]: /usr/ruby1.8.7/bin/thin:19:in `load'
2012-07-14T10:52:27+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/bin/thin:6
2012-07-14T10:52:27+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/controllers/controller.rb:80:in `start'
2012-07-14T10:52:27+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/runner.rb:177:in `send'
2012-07-14T10:52:27+00:00 heroku[router]: GET rhohub-tombarnard-482dfc2a.rhosync.com/application?client_id=ad17fd1c118943dd95df11f62d2f36d2&p_size=2000&version=3&source_name=Devicecache dyno=web.1 queue=0 wait=0ms service=338ms status=500 bytes=20
2012-07-14T10:52:27+00:00 heroku[nginx]: 212.183.128.12 - - [14/Jul/2012:10:52:27 +0000] "GET /application?client_id=ad17fd1c118943dd95df11f62d2f36d2&p_size=2000&version=3&source_name=Devicecache HTTP/1.1" 500 20 "-" "rhodes-wm" rhohub-tombarnard-482dfc2a.rhosync.com
2012-07-14T10:52:39+00:00 app[web.1]: config.ru:15: warning: already initialized constant ROOT_PATH
2012-07-14T10:52:39+00:00 app[web.1]: [03:52:39 AM 2012-07-14] stack level too deep/app/.gems/gems/redis-2.2.2/lib/redis/connection/command_helper.rb:26:in `string_size'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/connection/command_helper.rb:13:in `build_command'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/connection/command_helper.rb:11:in `each'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/connection/command_helper.rb:11:in `build_command'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/connection/ruby.rb:58:in `write'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:139:in `process'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:138:in `each'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:138:in `process'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:137:in `process'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:250:in `ensure_connected'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:136:in `process'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:206:in `logging'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis/client.rb:46:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis.rb:157:in `get'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/1.8/monitor.rb:242:in `synchronize'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/redis-2.2.2/lib/redis.rb:156:in `get'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/store.rb:114:in `get_value'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/source.rb:194:in `poll_interval'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/source.rb:269:in `if_need_refresh'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/source.rb:264:in `check_refresh_time'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/lock_ops.rb:8:in `lock'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/store.rb:214:in `lock'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/lock_ops.rb:7:in `lock'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/source.rb:268:in `if_need_refresh'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/source_sync.rb:63:in `do_query'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/source_sync.rb:57:in `process_query'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/client_sync.rb:32:in `send_cud'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/server.rb:243:in `GET /application'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/server.rb:153:in `catch_all'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/server.rb:241:in `GET /application'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:1211:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:1211:in `compile!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:785:in `[]'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:785:in `route!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:801:in `route_eval'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:785:in `route!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:822:in `process_route'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:820:in `catch'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:820:in `process_route'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:784:in `route!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:783:in `route!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:783:in `each'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:886:in `dispatch!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:719:in `call!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:871:in `catch'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:871:in `invoke'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:871:in `invoke'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:719:in `call!'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/static.rb:66:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/sinatra-1.3.2/lib/sinatra/base.rb:705:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/session/abstract/id.rb:205:in `context'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/session/abstract/id.rb:200:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/stats/middleware.rb:19:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-protection-1.2.0/lib/rack/protection/xss_header.rb:22:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rhosync-2.1.17/lib/rhosync/../rhosync/body_content_type_parser.rb:26:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/static.rb:66:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-protection-1.2.0/lib/rack/protection/path_traversal.rb:16:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-protection-1.2.0/lib/rack/protection/base.rb:47:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-protection-1.2.0/lib/rack/protection/json_csrf.rb:17:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-protection-1.2.0/lib/rack/protection/xss_header.rb:22:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/nulllogger.rb:9:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/urlmap.rb:49:in `each'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/head.rb:9:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/urlmap.rb:64:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /home/heroku_rack/lib/static_assets.rb:9:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/urlmap.rb:49:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/builder.rb:134:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /home/heroku_rack/lib/last_access.rb:15:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/urlmap.rb:64:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/urlmap.rb:49:in `each'
2012-07-14T10:52:39+00:00 app[web.1]: /home/heroku_rack/lib/date_header.rb:14:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/urlmap.rb:49:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /app/.gems/gems/rack-1.4.1/lib/rack/builder.rb:134:in `call'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/connection.rb:74:in `catch'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/connection.rb:76:in `pre_process'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/connection.rb:57:in `process'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/connection.rb:74:in `pre_process'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/connection.rb:42:in `receive_data'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run_machine'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/backends/base.rb:57:in `start'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/server.rb:156:in `start'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/controllers/controller.rb:80:in `start'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/runner.rb:177:in `send'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/runner.rb:177:in `run_command'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/lib/thin/runner.rb:143:in `run!'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/lib/ruby/gems/1.8/gems/thin-1.2.6/bin/thin:6
2012-07-14T10:52:39+00:00 heroku[router]: GET rhohub-tombarnard-482dfc2a.rhosync.com/application?client_id=3af00085ad1d410c82c049030c93210e&p_size=2000&version=3&source_name=Job dyno=web.1 queue=0 wait=0ms service=395ms status=500 bytes=20
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/bin/thin:19:in `load'
2012-07-14T10:52:39+00:00 app[web.1]: /usr/ruby1.8.7/bin/thin:19
2012-07-14T10:52:40+00:00 heroku[nginx]: 212.183.128.235 - - [14/Jul/2012:10:52:39 +0000] "GET /application?client_id=3af00085ad1d410c82c049030c93210e&p_size=2000&version=3&source_name=Job HTTP/1.1" 500 20 "-" "rhodes-wm" rhohub-tombarnard-482dfc2a.rhosync.com
2012-07-14T10:52:41+00:00 app[web.1]: config.ru:15: warning: already initialized constant ROOT_PATH