Java Heap Optimization

It is important to allocate enough memory to Java so that it properly uses available system resources and maximizes performance. The following are some guidelines for allocating memory to the Java Heap.

Set the Initial and Maximal heap settings to the same value. For example:

-Xms2g -Xmx2g

Note: at this time we do not recommend allocating more than 88GB to the Java Heap

The following document assumes that you are running Red5 Pro on a Debian/Ubuntu instance.

Linux File System Optimizations

• IMPORTANT You will first want to run cat /proc/sys/fs/file-max to make sure that the file-max can support the value we are setting below. If it can’t, then adjust accordingly
• Run ulimit -n to check the open file limits (default is 1024 – we want to increase this).

To maximize the open file settings, you will need to modify the following files:

• /etc/sysctl.conf – add the following lines:

fs.file-max = 1000000
kernel.pid_max = 999999
kernel.threads-max = 999999
vm.max_map_count = 1999999

• /etc/security/limits.conf – add the following four lines. If your process is running as a different user than root, you will want to add the same lines for that user, for example:

root soft nofile 1000000
root hard nofile 1000000
ubuntu soft nofile 1000000
ubuntu hard nofile 1000000

• /etc/pam.d/common-session – add the following line: session required pam_limits.so

Then run:

ulimit -n 1000000

And finally sysctl -p will reload the user sessions with your updated settings.

Red5 Pro Optimizations

jee-container.xml and red5.properties – tomcat settings

Modifying these settings are especially useful on a Stream Manager, which processes a lot of HTTP requests.

Modify the following values in red5pro/conf/red5.properties:

• http.max_threads=20 – The maximum number of request processing threads to be created by this Connector, which therefore determines the maximum number of simultaneous requests that can be handled. If not specified, this attribute is set to 200. If an executor is associated with this connector, this attribute is ignored as the connector will execute tasks using the executor rather than an internal thread pool. Note that if an executor is configured any value set for this attribute will be recorded correctly but it will be reported (e.g. via JMX) as -1 to make clear that it is not used.
• http.acceptor_thread_count=10 – The number of threads to be used to accept connections. Increase this value on a multi CPU machine, although you should never really need more than 2. Also, with a lot of non keep alive connections, you might want to increase this value as well.
• http.processor_cache=20 – The protocol handler caches Processor objects to speed up performance. This setting dictates how many of these objects get cached. -1 means unlimited, default is 200. If not using Servlet 3.0 asynchronous processing, a good default is to use the same as the maxThreads setting. If using Servlet 3.0 asynchronous processing, a good default is to use the larger of maxThreads and the maximum number of expected concurrent requests (synchronous and asynchronous).

Modify the <map> section of the red5pro/conf/jee-container.xml, adding in the following:

 <map>
            <entry key="port" value="${http.port}" />
            <entry key="redirectPort" value="${https.port}" />
            <entry key="maxHttpHeaderSize" value="${http.max_headers_size}"/>
            <entry key="maxKeepAliveRequests" value="${http.max_keep_alive_requests}"/>
            <entry key="keepAliveTimout" value="-1"/>
            <entry key="useExecutor" value="true"/>
            <!-- Maximum number of request processing threads to be created by this Connector -->
            <entry key="maxThreads" value="${http.max_threads}"/>
            <!-- Backlog of connections waiting to be accepted -->
            <entry key="acceptCount" value="1000"/>
            <!-- Number of threads to be used to accept connections -->
            <entry key="acceptorThreadCount" value="${http.acceptor_thread_count}"/>
            <!-- Protocol handler caches Processor objects to speed up performance -->
            <entry key="processorCache" value="${http.processor_cache}"/>
            <!-- Connection timeout alloting 20s for an accepted connection to present its request -->
            <entry key="connectionTimeout" value="20000"/>
            <!-- Negative one prevents connections from being counted -->
            <entry key="maxConnections" value="-1"/>
        </map>

Removing unnecessary plugins and webapps

Removing unnecessary plugins and webapps will always improve performance. The only webapps (in red5pro/webapps that are critical for normal Red5Pro operation are live and root (unless the instance is a Stream Manager, in which case streammanager is required). The webrtcexamples webapp contains the streaming html5 examples, and are useful for testing.

The following plugins can be removed (from red5pro/plugins) if you are not using them in your solution:

• red5pro-mpegts-plugin-*.jar – necessary for HLS streaming and recording
• red5pro-restreamer-plugin-*.jar – necessary for mpegts restreaming
• red5pro-webrtc-plugin-*.jar – necessary for WebRTC publishing and subscribing
• red5pro-autoscale-plugin-*.jar – necessary for Red5 Pro Autoscaling nodes

Note: if you remove the inspector webapp, you must also remove the inspector.jar from the red5pro/plugins directory

Increase Red5 Pro Service Open Files Setting

In the base configuration, the jsvc service open file limit is set to 65535. If you are increasing your open file limits, you should do the same for the Red5 Pro service (/lib/systemd/system/red5pro.service). Modify the

LimitNOFILE=

definition, from LimitNOFILE=65536 to LimitNOFILE=1000000, for example. Note: you will need to run sudo systemctl daemon-reload after you make any changes to the service file.