Redmine

Hello.
I use redmine 2.6.2 with nginx(fastcgi) + mysql.

Environment:
Redmine version 2.6.2.stable
Ruby version 1.9.3-p484 (2013-11-22) [x86_64-linux]
Rails version 3.2.21
Environment production
Database adapter Mysql2
SCM:
Git 2.3.1
Filesystem
Redmine plugins:
clipboard_image_paste 1.10
redmine_tags 2.1.0
sidebar_hide 0.0.7
spawn-fcgi v1.6.3 (ipv6) - spawns FastCGI processes
nginx version: nginx/1.0.15
Mysql 5.1.73
OS - CentOS release 6.6 (Final)

dispatch.fcgi:

#!/usr/bin/env ruby

require File.dirname(__FILE__) + '/../config/boot'
require File.dirname(__FILE__) + '/../config/environment'

class Rack::PathInfoRewriter
  def initialize(app)
    @app = app
  end

  def call(env)
    env.delete('SCRIPT_NAME')
    parts = env['REQUEST_URI'].split('?')
    env['PATH_INFO'] = parts[0]
    env['QUERY_STRING'] = parts[1].to_s
    @app.call(env)
  end
end

Rack::Handler::FastCGI.run Rack::PathInfoRewriter.new(RedmineApp::Application)

Sometimes redmine FastCGI process crash with error:

/opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:92:in `print': unknown error (syscall error) (FCGI::Stream::Error)
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:92:in `block in send_body'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/activerecord-3.2.21/lib/active_record/query_cache.rb:46:in `each'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/activerecord-3.2.21/lib/active_record/query_cache.rb:46:in `each'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract/connection_pool.rb:460:in `each'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/body_proxy.rb:31:in `each'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:91:in `send_body'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:69:in `serve'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:28:in `block in run'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:27:in `each'
        from /opt/rh/ruby193/root/usr/local/share/gems/gems/rack-1.4.5/lib/rack/handler/fastcgi.rb:27:in `run'
        from /srv/redmine/redmine-2.6.2/public/dispatch.fcgi:20:in `<main>'

What can I you do for avoid this error?