Heroku H13 Router Errors Reported in LogEntries

Question

I am trying to figure out whether to worry about these errors that I regularly get from LogEntries. I have an iPhone app that talks about the Rails API for a hero. I use HireFire to automatically increase and decrease the number of speakers and workers who need an application.

I assume that these erros are caused by a decrease in the number of speakers, and then something making this dinosaus call and therefore causing the H13 error. If so, is there a way to stop this? Of course, user queries will not go to dyno, which no longer exists?

Here are the most common magazines that I get in context:

1.

2012-10-18 10:01:15.170 209 <13>1 2012-10-18T10:01:14+00:00 app web.1 - - Started GET "/hirefireapp/xxxxxxxxxxxxxxxx/info" for 23.22.73.241 at Thu Oct 18 03:01:14 -0700 2012 2012-10-18 10:01:15.170 162 <13>1 2012-10-18T10:01:14+00:00 app web.1 - - cache: [GET /hirefireapp/xxxxxxxxxxxxxxxx/info] miss 2012-10-18 10:01:22.147 146 <13>1 2012-10-18T10:01:22+00:00 app web.2 - - Connected to NewRelic Service at collector-2.newrelic.com:80 2012-10-18 10:01:22.308 217 <13>1 2012-10-18T10:01:22+00:00 app web.2 - - ** [NewRelic][10/18/12 03:01:22 -0700 xxxxxxxxxxxxxxxx (2)] INFO : Reporting performance data every 60 seconds. 2012-10-18 10:01:38.118 86 <13>1 2012-10-18T10:01:38+00:00 app web.2 - - 2012-10-18 10:01:38.212 86 <13>1 2012-10-18T10:01:38+00:00 app web.2 - - 2012-10-18 10:01:38.212 154 <13>1 2012-10-18T10:01:38+00:00 app web.2 - - Started GET "/" for 204.93.223.151 at Thu Oct 18 03:01:38 -0700 2012 2012-10-18 10:01:38.212 128 <13>1 2012-10-18T10:01:38+00:00 app web.2 - - Processing by CmsController#index as */* 2012-10-18 10:01:38.212 148 <13>1 2012-10-18T10:01:38+00:00 app web.2 - - Rendered cms/index.html.erb within layouts/application (4.8ms) 2012-10-18 10:01:41.291 124 <40>1 2012-10-18T10:01:41+00:00 heroku web.2 - - Stopping all processes with SIGTERM 2012-10-18 10:01:42.243 217 <158>1 2012-10-18T10:01:42+00:00 heroku router - - Error H13 (Connection closed without response) -> GET my-api.heroku.com/ dyno=web.2 queue= wait= service= status=503 bytes= 

2.

 2012-10-16 17:31:25.184 189 <13>1 2012-10-16T17:31:25+00:00 app web.2 - - ** [NewRelic][10/16/12 10:31:25 -0700 (2)] INFO : Dispatcher: thin 2012-10-16 17:31:25.184 197 <13>1 2012-10-16T17:31:25+00:00 app web.2 - - ** [NewRelic][10/16/12 10:31:25 -0700 (2)] INFO : Application: my-api 2012-10-16 17:31:25.184 220 <13>1 2012-10-16T17:31:25+00:00 app web.2 - - ** [NewRelic][10/16/12 10:31:25 -0700 (2)] INFO : New Relic Ruby Agent 3.3.1 Initialized: pid = 2 2012-10-16 17:31:25.585 265 <13>1 2012-10-16T17:31:25+00:00 app web.2 - - ** [NewRelic][10/16/12 10:31:25 -0700 (2)] INFO : NewRelic::Agent::Samplers::DelayedJobLockSampler sampler not available: No DJ worker present 2012-10-16 17:31:37.068 217 <13>1 2012-10-16T17:31:37+00:00 app web.2 - - ** [NewRelic][10/16/12 10:31:36 -0700 (2)] INFO : Reporting performance data every 60 seconds. 2012-10-16 17:31:39.786 86 <13>1 2012-10-16T17:31:39+00:00 app web.2 - - 2012-10-16 17:31:39.884 86 <13>1 2012-10-16T17:31:39+00:00 app web.2 - - 2012-10-16 17:31:39.884 154 <13>1 2012-10-16T17:31:39+00:00 app web.2 - - Started GET "/" for xxx.xx.xxx.xxx at Tue Oct 16 10:31:39 -0700 2012 2012-10-16 17:31:39.884 128 <13>1 2012-10-16T17:31:39+00:00 app web.2 - - Processing by CmsController#index as */* 2012-10-16 17:31:39.981 149 <13>1 2012-10-16T17:31:39+00:00 app web.2 - - Rendered cms/index.html.erb within layouts/application (18.1ms) 2012-10-16 17:31:46.082 217 <158>1 2012-10-16T17:31:46+00:00 heroku router - - Error H13 (Connection closed without response) -> GET my-api.heroku.com/ dyno=web.2 queue= wait= service= status=503 bytes= 

Any advice would be highly appreciated!

Thanks Pete

Answer 1

One potential cause of the H13 problem is the Rack keyspace. Rack adds protection against a possible malicious attack by sending significantly larger parameter keys with an HTTP request.

Rack Utils sets a 65536 key space limit, which may not be large enough if you send HTTP requests with large sets of parameters.

You can change this limit by adding the following to the Rails initialization file:

 if Rack::Utils.respond_to?("key_space_limit=") Rack::Utils.key_space_limit = 262144 end 

I found this figure (4x standard) large enough to fix the H13 problems for me, but you may have to test different settings to suit your personal requirements.

This may not be the cause of your specific H13 problem, but it is worth checking it out as a possible solution.