The LOAD/-LOAD command

[-]LOAD J=<jurl> | X=<url> | A=<url> | F=<url> [F=<url> ...]
        [T=<anep_id>] [N=<num>] [V=<jdk>] [S=<arg> ...] [E=<var:val> ...]
        [D=<dir>] [C=<description>] [I=<file>] [O=<file>] [R=<file>]
        [G=<debug_option>] [K=0|1|false|true|no|yes]

Instructs Anetd to download one or more files specified by URLs to a principal's working directory (or a subdirectory thereof), and optionally start a network service. Note: As of version 1.6, Anetd will permit the use of file URLs (file:///) only if authorized by the TCL (see also section 3.2.2).

See section 3.8.1 for the meaning of the optional -.

• J=$<$jurl$>$ specifies a Java application.
  $<$jurl$>$ is of the form http://host[:port]/classpath/~class or file://[localhost]/classpath/~class where
  • host[:port] specifies the server where the data is located following the normal URL conventions.
  • classpath is a path pointing to the base classpath of the Java application.
  • class is the class to invoke.

  Both classpath and class can be a series of directories separated by ``/''. For example, J=http://abone-tcs.sdl.sri.com/java/ants-1.2/~ants/ConfigurationManager specifies the URL of the ANTS application ants.ConfigurationManager located on SRI's http code server in the directory java/ants-1.2/.

• X=$<$url$>$ means that $<$url$>$ specifies a native binary executable.

• A=$<$url$>$ means that $<$url$>$ specifies an ANCORS thread. (see [2]).

• F=$<$url$>$ means that $<$url$>$ specifies a data file that should be simply transferred and stored in the local installation directory (see the D option for the meaning of installation directory in this context). The F option can be used independently or in conjunction with the J or X options. It is often used independently to preload certain files (such as configuration files) for use in subsequent invocations of EEs. Note that the F option may be used multiple times in a single command to load multiple files. When this option is used in conjunction with J or X, the specified EE is started only after all files specified in the command are successfully downloaded.

• T=$<$anep_id$>$ is the ANEP ID of the service being deployed. If this argument is not present no packets will be demultiplexed to it by Anetd.

• N=$<$num$>$ limits the maximum number of URL download attempts (using TCL- and DNS-equivalent rewrites^e). Default is 0 (no limit). If $<$num$>$ = 1, then Anetd will try only the exact URL specified on the LOAD command line.

• V=$<$jdk$>$ tells Anetd to use the Java JVM version specified by $<$jdk$>$, eg V=jdk1.1.8. If this option is not present a default Java version will be used. If the version is only partially specified (e.g., jdk1.1), Anetd will use the first configured JDK whose version is prefix-matched by the requested version. See section 3.8.4 for information on how to determine which JDK versions are available on a node.

• S=$<$arg$>$ tells Anetd to invoke the deployed service with $<$arg$>$ as a command line argument. $<$arg$>$ cannot contain any white space, so multiple arguments can be passed to the command line by using multiple instances of S=$<$arg$>$.

• E=$<$variable$>$:$<$value$>$ tells Anetd to set the environment variable $<$variable$>$ to the value $<$value$>$. Note that Anetd itself sets several environment variables. In most cases, the variables set by Anetd cannot be set effectively via the E option. The environment variables set by Anetd are as follows:
  • CLASSPATH: where Java may look for class files/libraries. This variable is set by Anetd to include first the local directory containing ABOCC class files (usually ~abocc/anetd/bin) and second the EE working directory (including any subdirectory component specified by the D option, if any).
  • LD_LIBRARY_PATH: where the node may look for native shared libraries. This variable is currently set to the same value as CLASSPATH.
  • DISPLAY: the address of an X server display to be used by the EE for any windows it may open. If a value for DISPLAY is set via an E option, Anetd leaves that setting intact. Otherwise, Anetd sets DISPLAY to "<client-IP-addr>:0.0", where <client-IP-addr> is the address of the host from which the LOAD command was issued. Note that the principal issuing the command is responsible for dealing with any X Window System authentication issues that may arise in the use of remote X servers.
  The remaining variables set by Anetd are listed below for completeness. They are intended for use primarily by ABOCC for administrative purposes.
  • AD_DIR: the Anetd installation directory
  • AD: the name of the Anetd executable
  • AD_PID: the Unix process ID of the Anetd process
  • AD_COMMAND: the full command line used to start the current Anetd process
  • AD_START_DIR: Anetd's working directory at the time the parent Anetd process was started
  • AD_CWD: Anetd's working directory at the time the child process was started
  • AD_USER: the OS account in which the Anetd process is running
  • AD_ABONE_ROLE: the ABone role in which the Anetd process is acting
  • AD_ABOCC_USER: the OS account of the Anetd process that is acting in the abocc role.

• D=$<$dir$>$ tells Anetd to use the directory $<$dir$>$ as the root directory for the service installation. Anetd by default uses the directory $(anetd_var)/$<$clientip$>$/ for installing all downloaded code; by specifying the D=$<$dir$>$ option, Anetd installs all downloaded code in $(anetd_var)/$<$clientip$>$/$<$dir$>$.

• I=$<$file$>$ redirects the standard input of the network service to the file $<$file$>$ (to be created in the installation directory via the F option, otherwise this option is meaningless).

• O=$<$file$>$ redirects the standard output of the network service to the file $<$file$>$ (to be created in the installation directory).

• R=$<$file$>$ redirects the standard error of the network service to the file $<$file$>$ (to be created in the installation directory).

• C=$<$description$>$ specifies a description $<$description$>$ for the deployed services. This description is then returned to the client when QUERY commands are invoked. ABOCC requires this field to be a unique name for the EE, e.g., "ANTS" or "ANTSv1.3.1".

• G=$<$debug_option$>$ specifies debug option for debugging EE remotely. The option can be either host:port or java. See Section 3.9 for more information.

• K=0$\vert$1$\vert$false$\vert$true$\vert$no$\vert$yes specifies whether the autokill option is set. When the autokill option is set, Anetd attempts to terminate the EE automatically when Anetd is shut down. If the autokill option is not set, Anetd will not attempt to terminate the EE automatically; however, it may still be signaled or terminated explicitly via the KILL command. The autokill option is set by default and can be overridden (K=0$\vert$false$\vert$no) only by a principal with sufficient privilege.

Example 3.2
For initiating an ASP EE on some node, the command is

sc.solaris host LOAD J=http://bro.isi.edu/ASP/~asp/AspMain
T=15 S=-d0 S=-l7 O=output R=error C=ASP_EE

For loading an ASP EE as a permanent EE on some node:

sc.solaris host -LOAD J=http://bro.isi.edu/ASP/~asp/AspMain
T=15 S=-d0 S=-l7 O=output R=error C=ASP_EE

Because the X and A types specify native executables, Anetd automatically appends the extensions solaris, linux, and bsd44 to the URLs, depending on what platform Anetd is running on. For example, suppose that Anetd is running on a Linux machine; the URL http://abone-tcs.sdl.sri.com/executables/ps would actually fetch the file http://abone-tcs.sdl.sri.com/executables/ps.linux.