Java VM Properties Files

Java Virtual Machine properties files may be used to pass additional options to a Java Virtual Machine running Iotellect Server. Those files are located in the Iotellect installation folder. The name of each property file matches the name of the corresponding executable file, and the extension of each file is .vmoptions.

The additional Java Virtual Machine properties are read from the file iot_server.vmoptions when launching iot_server, %LS_BINARY%_console.vmoptions when launching %LS_BINARY%_console, and %LS_BINARY%_service.vmoptions when launching %LS_BINARY%_service.

In the *.vmoptions files, each line is interpreted as a single VM parameter.

It's absolutely necessary to add the newline character (i.e. press ENTER) in the end of every line of the *.vmoptions file, including the final line.

Even if there is a single line in the file, a newline must be added.

Omitting the newline character at the end of the line will result in the line being ignored.

Changing Language

Each *.vmoptions file contains the -Duser.language=XX option to define the language used by Iotellect Server. The default language is selected during the Iotellect Server installation process.

Changing the language option after the first launch of Iotellect Server will not update data already contained in the database (such as system resource descriptions, events, etc.) which were created in the language that was active during previous launches.

Modifying Classpath

The following options may be added to the *.vmoptions files to modify the classpath of the Iotellect Server's Java Virtual Machine:

-classpath [classpath]

Replace the classpath of the generated launcher.

-classpath/a [classpath]

Append to the classpath of the generated launcher.

-classpath/p [classpath]

Prepend to the classpath of the generated launcher.

It's necessary to put exactly one space between -classpath parameter and its value.

NEW TERM: A class path is the directory path specifying where compiled Java files are located on the local system.

Append to classpath option of Launcher Properties File may be useful when making new Java libraries available to Iotellect Server. For example, Java Database Connectivity (JDBC) driver file path should be appended to the classpath when switching to another database engine.

Adjusting Memory Usage

The following options may be added to the *.vmoptions files in order to control the amount of memory used by Iotellect Server:

-Xms

Initial amount of memory used by Iotellect Server. This parameter should be followed by the number of megabytes and m character, no spaces are allowed inside.

For example, -Xms200m parameter instructs the Iotellect Server to use 200 megabytes of memory at startup.

Default value is 500 megabytes.

-Xmx

Maximum amount of memory that can be used by Iotellect Server. This parameter should be followed by the number of megabytes and m character, no spaces are allowed inside.

For example, -Xmx1024m parameter allows Iotellect Server to use a maximum of 1 gigabyte.

Default value is 800 megabytes.

Too high value of -Xmx parameter may cause Iotellect Server startup to fail because Java Virtual Machine needs this amount of memory to be available in a single contiguous block. In this case, switch to a 64-bit operating system and install 64-bit version of Iotellect Server.

-Xss

Stack size of a single server thread, 512 kilobytes by default. Stack size should be decreased if thread creation failures caused Out Of Memory errors appear in Iotellect Server log file.

Increase stack size if some device drivers or system components produce Stack Overflow errors.

Setting up Proxy Server

The following options may be added to the *.vmoptions files in order to enable usage of the proxy server by Iotellect Server to reach the Internet:

-Dhttp.proxyHost

The hostname, or address, of the HTTP proxy server

-Dhttp.proxyPort

The port number of the HTTP proxy server

-Dhttp.proxyUser

Username to use if the HTTP proxy server asks for authentication

-Dhttp.proxyPassword

Password to use if the HTTP proxy server asks for authentication

-Dhttp.nonProxyHosts

Indicates the hosts that should be accessed without going through the proxy. Typically this defines internal hosts. The value of this property is a list of hosts, separated by the '|' character. In addition the wildcard character '*' can be used for pattern matching. For example -Dhttp.nonProxyHosts=”*.foo.com|localhost” will indicate that every host in the foo.com domain and the localhost should be accessed directly even if a proxy server is specified.

Note that the HTTPS protocol handler will use the same nonProxyHosts property as the HTTP protocol.

-Dhttps.proxyHost

The hostname, or address, of the HTTPS proxy server

-Dhttps.proxyPort

The port number of the HTTPS proxy server

-Dhttps.proxyUser

Username to use if the HTTPS proxy server asks for authentication

-Dhttps.proxyPassword

Password to use if the HTTPS proxy server asks for authentication

-Dsocks.proxyHost

The hostname, or address, of the SOCKS proxy server

-Dsocks.proxyPort

The port number of the SOCKS proxy server

-Dsocks.proxyUser

Username to use if the SOCKSv5 server asks for authentication

-Dsocks.proxyPassword

Password to use if the SOCKSv5 server asks for authentication

SOCKS allows for lower level type of tunneling since it works at the TCP level. Setting a SOCKS proxy server will result in all TCP connections to go through that proxy, unless other proxies are specified.

Adjusting Socket Usage Options

The following options may be added to the *.vmoptions files in order to change the network parameters used by Iotellect Server:

-Dsun.net.maxDatagramSockets

Sets the maximum number of datagram sockets. You can use this option to increase the number of UDP sockets that can be used by the Java Virtual Machine. For example, you may do so when you try to synchronize a large number of devices and encounter a "maximum number of datagram Sockets reached" SNMP error.

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