JRuby on Rails Tomcat logging

We have a mixed dev team - Windows and Linux currently, although I'm considering a Mac.

In your environment:

os = java.lang.System.get_property 'os.name'

config.logger = Logger.new('/var/log/my-company/my-app/rails.log', 5, 104857) if os.downcase =~ /linux/

Scripting JMX via JRuby

I'm gradually growing some operations scripts which use JMX to alter application behaviour according to system load / required maintenance, etc. JRuby is a nice easy way to create these scripts.

host = 'some-ip'
port = 'port-number'
serviceUrl = javax.management.remote.JMXServiceURL.new("service:jmx:rmi:///jndi/rmi://#{host}:#{port}/jmxrmi")
connector = javax.management.remote.JMXConnectorFactory.connect(serviceUrl)
remote = connector.getMBeanServerConnection()
remoteRuntime = java.lang.management.ManagementFactory.newPlatformMXBeanProxy(remote, 
                     java.lang.management.ManagementFactory::RUNTIME_MXBEAN_NAME, 
                     java.lang.management.RuntimeMXBean.java_class)
p remoteRuntime.getName()
connector.close()

Java REPL

Obviously, most good dynamic languages for the JVM have this, but still, it's sweet.

$ jirb 
irb(main):001:0> require 'lib/org.restlet.jar'
=> true
irb(main):002:0>  http = Java::OrgRestletData::Protocol::HTTP
=> #<Java::OrgRestletData::Protocol:0x59cbda @java_object=#>
irb(main):003:0> client = Java::OrgRestlet::Client.new http 
=> #<Java::OrgRestlet::Client:0x800aa1 @java_object=#>
irb(main):004:0> r = client.get 'http://www.apache.org/'
01-Feb-2009 22:54:08 org.restlet.engine.http.StreamClientHelper start
INFO: Starting the HTTP client
=> #<Java::OrgRestletData::Response:0x12a416a @java_object=#>