Posts Tagged ‘ Red5 ’

Socket bind exception on Red5 restart

This one is a gem. We’re using Red5 as flash server for several of our projects and one annoying problem that we encountered were thrown exceptions on Red5 restart. Specifically, Address already in use exception which signals that a socket is still being used. The culprit is socket bound to 1935 port which is used for rtmp traffic between flash clients and Red5. That socket remained in TIME_WAIT state even after Red5 was shutdown.

Now, it is important to note that tcp connections should be closed properly in order to avoid this sort of problems, but this is not always possible (unexpected server shutdown, bug which makes server unresponsive, etc.). Brief discussion about proper tcp handling is here. I know from experience that other servers (for example Tomcat) don’t have this problem with socket binding (at least not in the last ~5 years) and I was curious why Red5 developers haven’t solved this. The thing to do to avoid this is to set SO_REUSEADDR flag on the socket. This means that other processes can bind to this socket if it is in TIME_WAIT state. Fortunately, Red5 is open source, so I browsed a bit and found this in RTMPMinaTransport class :

acceptor = new NioSocketAcceptor(ioThreads);
acceptor.setBacklog(100);“TCP No Delay: {}”, tcpNoDelay);“Receive Buffer Size: {}”, receiveBufferSize);“Send Buffer Size: {}”, sendBufferSize);

SocketSessionConfig sessionConf = (SocketSessionConfig) acceptor.getSessionConfig();

Interesting enough, they do set this flag as I’ve shown with the bolded line. So I’ve tried debugging the code and after some time I’ve found out, that SocketSessionConfig is never read, never used. I will repeat this : SocketSessionConfig is never accessed. That part of the code could as well be removed. The solution is simple, flag must be set directly on NioSocketAcceptor and then the socket can be bound on restart without a problem:

acceptor = new NioSocketAcceptor(ioThreads);

I’ve added the bolded line and compiled the source. With new red5.jar, restarting works like a charm.

How To Install RED5 version 0.8 on CENTOS

Step 1: Download and Install Java
RED5 depends on Java, so lets install it using yum.
# yum -y install java-1.6.0-openjdk java-1.6.0-openjdk-devel

Step 2: Download and Install Ant(Apache Project)
Ant will be needed to compile RED5 server code.
# cd /usr/src

Note: Link may be broken or may cause problems because they are always updating the apache ant and changing the filename.
For updated link if link is broken:
# wget
# tar zxvf apache-ant-1.8.1-bin.tar.gz
# mv apache-ant-1.8.1/ /usr/local/ant

Step 3: Export Variables for Ant and Java
# export ANT_HOME=/usr/local/ant
# export JAVA_HOME=/usr/lib/jvm/java
# export PATH=$PATH:/usr/local/ant/bin
# export CLASSPATH=.:$JAVA_HOME/lib/

Also export these variables in /etc/bashrc to become available for every user login or for any terminal opens.

# echo ‘export ANT_HOME=/usr/local/ant’ >> /etc/bashrc
# echo ‘export JAVA_HOME=/usr/lib/jvm/java’ >> /etc/bashrc
# echo ‘export PATH=$PATH:/usr/local/ant/bin’ >> /etc/bashrc
# echo ‘export CLASSPATH=.:$JAVA_HOME/lib/’ >> /etc/bashrc

Step 4: Download and Install RED5 Server
# cd /usr/src
# svn co red5
# mv red5 /usr/local/
# cd /usr/local/red5
# ant prepare
# ant dist

you will see lots and lots of lines, but you should get at last


that’s mean its install and now copy the conf directory from dist/ and test the red5 installation.

# cp -r dist/conf .
# ./

If it shows Installer service created in the last then everything is fine here, press ctrl+c

Step 5: Starting RED5 Server

Now go to the red5 folder:

# cd /usr/local/red5/dist
command to stop red5:
# sh
# killall -9 java

Command to start red5:
# sh &

When Red5 is running you should be able to access http://your-server-domain-or-ip:5080/ .

If it works first thing go to http://your-server:5080/installer/and install admin. Then to http://your-server:5080/admin/register.html and register an username and password. Then you can check application statistics anytime from http://your-server:5080/admin/ with server ip and the registered username, password.


You need to restart every time you add or update files in the /usr/local/red5/dist/webapps folder – where all applications should be installed.


[INFO] [main] org.red5.server.tomcat.TomcatLoader – RTMPT server bean was not found
[INFO] [main] org.red5.server.tomcat.TomcatLoader – RTMPS server bean was not found

Then RTMPT doesn’t work, It was disabled by default. To enable it, uncomment RTMPT and RTMPS on your conf/red5-core.xml