netty_server

created by kiwi 23/9/2016

Overview

A lightweight server using netty that can accommodate around 20,000 request/s on a normal server.

Dependencies:

Kafka APIs

• Download: https://www.apache.org/dyn/closer.cgi?path=/kafka/0.10.0.1/kafka_2.11-0.10.0.1.tgz

• The entire libs directory should be imported as external libraries.

Netty APIs

• Download: https://dl.bintray.com/netty/downloads/:netty-4.1.5.Final.tar.bz2

• Version: netty-4.1.5.Final

• Just importing netty-all-4.1.5.Final is enough for our development.

Java SDK (7 or 8)

Project structure:

Netty server program

• HttpJsonServer

• HttpJsonServerHandler

• HttpJsonServerInitializer

Saving request data to files

• FileWriteHelper

Sending request data to Kafka servers

• JsonKafkaProducer

Saving request data to local files

1. A scheduler is started as the Netty server starts, which schedules the swap (or write to new files) of saving file names every interval of time

2. Only one instance of FileWriter is instantiated, in order to improve the performance.

3. Request data are immediately flushed to disk, in order to prevent loss due to memory overflow.

4. Writing to files is async, thus imposing little effect on the server's request serving performance.

Notes

Which method to schedule (swap or writeToNewFile) is now hard coded. For now, writetoNewFile is used.

Sending request data of Kafka servers

1. The producer API documentation is found here. https://kafka.apache.org/0100/javadoc/index.html?org/apache/kafka/clients/producer/KafkaProducer.html

2. Only one instance of Producer is instantiated, in order to improve the performance.

3. As we are going to directly invoke the Java API provided by Kafka, the following changes must be made to the server.properties config file on the kafka servers. The addresses must be provided, if we want to use the Java APIs.

   ############################# Socket Server Settings ##########################$
   
   # The address the socket server listens on. It will get the value returned from
   # java.net.InetAddress.getCanonicalHostName() if not configured.
   #   FORMAT:
   #     listeners = security_protocol://host_name:port
   #   EXAMPLE:
   #     listeners = PLAINTEXT://your.host.name:9092
   listeners=PLAINTEXT://192.168.1.22:9092
   
   # Hostname and port the broker will advertise to producers and consumers. If no$
   # it uses the value for "listeners" if configured.  Otherwise, it will use the $
   # returned from java.net.InetAddress.getCanonicalHostName().
   advertised.listeners=PLAINTEXT://192.168.1.22:9092
   

Notes

Note, now it supports to import a custom Kafka producer properties file from the arguments.

Deployment

• Install JDK, and supervisor

• Build articfacts, which will generate a jar file

• Send the jar file to netty server, and create a custom Kafka producer properties file (remember its path)

• Create netty.conf, and add it to /etc/supervisor/conf.d/. An example may look like

   [program:netty]
   command:java -cp /home/alikeaudience/KiwisExperiments/JsonServer.jar jsonserver.alikeaudience.com.HttpJsonServer 10 /home/alikeaudience/netty_kafka.properties test4 sdk
   autostart:true
   autorestart:true
  

  • 1st argument: file swap interval in minutes
  • 2nd argument: Kafka producer properties file path
  • 3rd argument: Kafka topic name
  • 4th argument: Kafka topic key
  • In the example config file, the netty program will set the file swap interval to 5 minutes, load the Kakfa producer properties file in the specifed path, set the Kafka topic to test4, and finally set the Kafka topic key to sdk.

• start supervisor and load conf

  • sudo service supervisor restart
  • sudo supervisorctl reread
  • sudo supervisorctl update

• To stop netty program, simply stop supversior, or stop netty using sudo supervisorctl

Recommended IDE and test software

• IntelliJ IDEA

• JMeter