jsv_script_interface (3) - Linux Manuals

jsv_script_interface: xxQS_NAMExx Job Submission Verifier Scripting Interface

NAME

jsv_is_param, jsv_get_param, jsv_del_param, jsv_sub_is_param, jsv_sub_get_param, jsv_sub_add_param, jsv_sub_del_param, jsv_is_env, jsv_get_env, jsv_add_env, jsv_mod_env, jsv_del_env, jsv_accept, jsv_correct, jsv_reject, jsv_reject_wait, jsv_show_params, jsv_show_envs, jsv_log_info, jsv_log_warning, jsv_log_error, jsv_main, jsv_logging_enabled - xxQS_NAMExx Job Submission Verifier Scripting Interface

SYNOPSIS

jsv_clear_params();

jsv_is_param(param_name);

jsv_get_param(param_name);

jsv_set_param(param_name, param_value);

jsv_del_param(param_name);

jsv_sub_is_param(param_name, variable_name);

jsv_sub_get_param(param_name, variable_name);

jsv_sub_add_param(param_name, variable_name, variable_value);

jsv_sub_del_param(param_name, variable_name);

jsv_clear_envs();

jsv_is_env(variable_name);

jsv_get_env(variable_name);

jsv_add_env(variable_name, variable_value);

jsv_mod_env(variable_name, variable_value);

jsv_del_env(variable_name);

jsv_accept(message);

jsv_correct(message);

jsv_reject(message);

jsv_reject_wait(message);

jsv_show_params();

jsv_show_envs();

jsv_log_info(message);

jsv_log_warning(message);

jsv_log_error(message);

jsv_main();

jsv_send_env();

jsv_on_start();

jsv_on_verify();

DESCRIPTION

The functions documented here implement the server side of the JSV protocol as described in (where "server" applies to both client- and server-side JSVs). These functions are available in Bourne shell (preferably using bash(1) for greater efficiency), TCL, Perl, or Python scripts after sourcing/including the files jsv_inlcude.sh, jsv_include.tcl, JSV.pm, or JSV.py. The files and corresponding JSV script templates are located in the directory $SGE_ROOT/util/resources/jsv. There is also a Java implementation which has a different structure, with Javadoc documentation normally in $SGE_ROOT/doc/javadocs/jjsv, and example files SimpleJsv.java and jjsv.sh in $SGE_ROOT/util/resources/jsv.

Note that Bourne shell server JSVs are discouraged because any problems with unintended expansion of job parameters represent a security hazard (with the qmaster running as the sgeadmin user). Also they may be relatively slow, and constitute a bottleneck in high-throughput clusters. However, shell JSVs may be faster using even compared with a generally faster shell, since fewer external commands are invoked.

In the descriptions of routines here, a calling sequence like

function(arg1, arg2)

should be interpreted for Bourne shell and Tcl scripts as

function arg1 arg2

jsv_clear_params()

This function clears all received job parameters that were stored during the last job verification process.

jsv_clear_envs()

This function clears all received job environment variables that were stored during the last job verification process.

jsv_show_params()

A call of this function reports all known job parameters to the counterpart of this script (client or master daemon thread). These parameters will be reported as info messages and appear either in the stdout stream of the client or in the message file of the master process.

jsv_show_envs()

This function reports all known job environment variables to the counterpart of this script (client or master daemon thread). They will be reported as info messages and appear in the stdout stream of the client or in the message file of the master process.

jsv_is_param(param_name)

This function returns whether or not a specific job parameter is available for the job which is currently being verified. Either the string true or false will be returned. The availability/absence of a job parameter does not mean that the corresponding command line switch was used/not used.

The values allowed for param_name are listed below. Find additional information in describing the availability and value format. Job parameters written in capital letters are pseudo parameters. A detailed description for them can be found in Note that

The following parameters directly reflect arguments of the same name supplied to the submission command (qsub etc.) or corresponding values specified with qmon:
A, a, ar, b, ckpt, dl, e, h, hold_jid, hold_jid_ad, i, j, js, M, m, masterq, N, notify, o, P, p, R, r, S, shell, tc, w
Other parameters are related to the submission command arguments as follows:

ac

The the job context. The outcome of the evaluation of all -ac, -dc, and -sc options is passed as a parameter with the name ac, whose value is a comma-separated list of variable/value pairs;

binding_strategy, binding_type, binding_amount, binding_step, binding_socket, binding_core, binding_exp_n, binding_exp_socketid, binding_exp_coreid

The values passed to the -binding parameter are passed as multiple parameters to JSV instances. binding_strategy represents the strategy to be used and is one of: linear, striding or explicit. binding_type is the instance that should do the binding, one of: env, set or pe. binding_socket and binding_core are socket/core values whereas binding_step is the step size (used only for striding binding). The length of the socket/core value list of the explicit binding is reported as binding_exp_n. The id part of binding_exp_socketid and binding_exp_coreid will be replaced by the position of the socket/core pair within the explicit binding list (0 <= id < binding_exp_n). The first socket/core pair of the explicit binding will be reported with the parameter names binding_exp_socket0 and binding_exp_core0. Values that do not apply for the specified binding will not be reported to JSV. E.g. binding_step will only be reported for the striding binding and all binding_exp_... values will only be passed if explicit binding was specified.

c_interval

Checkpoint interval, specified as a numeric value with -c;

c_occasion

Checkpoint "occasion_specifier" -c. (n, s, m, or x) specified with -c;

cwd

Working directory, possibly specified with -cwd or -wd;

display

Reflects the -display submit argument and also sets job environment variable DISPLAY to the same value;

l_hard

-l or -hard followed by -l;

l_soft

-soft followed by -l;

pe_name, pe_min, pe_max

The PE name and range limits specified with -pe;

q_hard

-q, or -hard followed by -q;

q_soft

-soft followed by -q.

See for explanation of the following pseudo parameters: CLIENT, CMDNAME, CMDARGS, CMDARGi, CONTEXT, GROUP, JOB_ID, USER, VERSION.

jsv_get_param(param_name)

This function returns the value of a specific job parameter param_name.

This value is only available if the function jsv_is_param() returns true. Otherwise an empty string is returned.

Find a list of allowed parameter names in the section for the function jsv_is_param().

jsv_set_param(param_name, param_value)

This function changes the job parameter param_name to the value param_value.

If param_value is an empty string then the corresponding job parameter will be deleted, similarly to the function jsv_del_param(). As a result, the job parameter is not available, as if the corresponding command line switch was not specified during job submission.

For boolean parameters that only accept the values yes or no it is not allowed to pass an empty string as param_value.

Also for the parameters c and m it is not allowed to use empty strings. Details can be found in

jsv_del_param(param_name)

This function deletes the job parameter param_name.

Find a list of allowed parameter names in the section for the function jsv_is_param().

jsv_sub_is_param(param_name, variable_name)

Some job parameters are lists that can contain multiple variables with an optional value.

This function returns true if a job's parameters contain the list-valued param_name, with variable_name in the list; otherwise it returns false. false might also indicate that the parameter list itself is not available. Use the function jsv_is_param() to check if the parameter list is not available.

The following parameters are list parameters. The second column describes the corresponding variable names to be used. The third column contains a dash (-) if there is no value (variable_value) allowed with the function jsv_sub_add_param() or jsv_sub_get_param() will return always an empty string. A question mark (?) shows that the value is optional.

param_name description of variable_name variable_value ac job context variable name hold_jid job identifier - hold_jid_id array job identifier - l_hard complex attribute name ? l_soft complex attribute name ? M mail address - masterq cluster queue name or -   queue instance name q_hard cluster queue name or -   queue instance name    q_soft cluster queue name or -   queue instance name

jsv_sub_get_param(param_name, variable_name)

Some job parameters are lists that can contain multiple variables
with an optional value.

This function returns the value of a variable variable_name in the parameter list param_name. For sub list elements that have no value an empty string will be returned.

Find a list of allowed parameter names (param_name) and variable names (variable_name) in the section for the function jsv_sub_is_param().

jsv_sub_add_param(param_name, variable_name, variable_value)

Some job parameters are lists that can contain multiple variables with an optional value.

This function either adds a new variable with a new value or it modifies the value if the variable is already in the list. variable_value is optional, and if it is not supplied the variable has no value.

Find a list of allowed parameter names (param_name) and variable names (variable_name) in the section for the function jsv_sub_is_param().

jsv_sub_del_param(param_name, variable_name)

Some job parameters are lists which can contain multiple variables with an optional value.

This function deletes a variable variable_name and, if available, the corresponding value. If variable_name is not available in the job parameter then the command will be ignored.

Find a list of allowed parameter names (param_name) and variable names (variable_name ) in the section for the function jsv_sub_is_param().

jsv_is_env(variable_name)

If the function returns true, then the job environment variable with the name variable_name exists in the job currently being verified, and jsv_get_env() can be used to retrieve the value of that variable. If the function returns false, then the job environment variable does not exist.

jsv_get_env(variable_name)

This function returns the value of a job environment variable variable_name.

This variable has to be passed with the qsub command line switch -v or -V, and passing of environment variable data to JSV scripts has to be enabled. Environment variable data are passed when the function jsv_send_env() is called in the callback function jsv_on_start().

If the variable does not exist, or if environment variable information is not available, then an empty string will be returned.

jsv_add_env(variable_name, variable_value)

This function adds an additional environment variable to the set of variables that will exported to the job when it is started. As a result the variable_name and variable_value become available, as if -v Or -V was specified during job submission.

variable_value is optional. If an empty string is passed, then the variable is defined without a value.

If variable_name already exists in the set of job environment variables, the corresponding value will be replaced by variable_value, as if the function jsv_mod_env() was used. If an empty string is passed then the old value will be deleted.

To delete an environment variable, the function jsv_del_env() has to be used.

jsv_mod_env(variable_name, variable_value)

This function modifies an existing environment variable that is in the set of variables which will exported to the job when it is started. As a result, the variable_name and variable_value will be available as if -v Or -V was specified during job submission.

variable_value is optional. If an empty string is passed, then the variable is defined without a value.

If variable_name does not already exist in the set of job environment variables, then the corresponding name and value will be added as if the function jsv_add_env() was used.

To delete a environment variable, use the function jsv_del_env().

jsv_del_env(variable_name)

This function removes job environment variable variable_name from the set of variables that will be exported to the job when it is started.

If variable_name does not already exist in the set of job environment variables then the command is ignored.

To change the value of a variable use the function jsv_mod_env(); to add a new value, call the function jsv_add_env().

jsv_accept(message)

This function can only be used in jsv_on_verify(). After it has been called, the function jsv_on_verify() has to return immediately.

A call to this function indicates that the job that is currently being verified should be accepted as it was initially provided. All job modifications that might have been applied in jsv_on_verify() before this function was called, are then ignored.

Instead of calling jsv_accept() in jsv_on_verify(), the functions jsv_correct(), jsv_reject() or jsv_reject_wait() can be called, but only one of these functions can be used at a time.

jsv_correct(message)

This function can only be used in jsv_on_verify(). After it has been called, the function jsv_on_verify() has to return immediately.

A call to this function indicates that the job that is currently being verified has to be modified before it can be accepted. All job parameter modifications that were previously applied will be committed and the job will be accepted. "Accept" in that case means that the job will either be passed to the next JSV instance for modification or that it is passed to that component in the master daemon that adds it to the master data store when the last JSV instance has verified the job.

Instead of calling jsv_correct() in jsv_on_verify(), the functions jsv_accept(), jsv_reject() or jsv_reject_wait() can be called, but only one of these functions can be used.

jsv_reject(message)

This function can only be used in jsv_on_verify(). After it has been called the function jsv_on_verify() has to return immediately.

The job that is currently being verified will be rejected. message will be passed to the client application that tried to submit the job. Commandline clients like qsub will print that message to stdout to inform the user that the submission has failed.

jsv_reject_wait() should be called if the user may try to submit the job again. jsv_reject_wait() indicates that the verification process might be successful in the future.

Instead of calling jsv_reject() in jsv_on_verify(), the functions jsv_accept(), jsv_correct() or jsv_reject_wait() can be called, but only one of these functions can be used.

jsv_reject_wait(message)

This function can only be used in jsv_on_verify(). After it has been called the function jsv_on_verify() has to return immediately.

The job which is currently verified will be rejected. message will be passed to the client application, that tries to submit the job. Commandline clients like qsub will print that message to stdout to inform the user that the submission has failed.

This function should be called if the user who tries to submit the job might have a chance to submit the job later. jsv_reject indicates that the verified job will also be rejected in future.

Instead of calling jsv_reject_wait() in jsv_on_verify() the functions jsv_accept(), jsv_correct() or jsv_reject() can be called, but only one of these functions can be used.

jsv_log_info(message)

This function sends an info message to the client or master daemon instance that started the JSV script.

For client JSVs, this means that the command line client will get the information and print it to the stdout stream. Server JSVs will print that message as an info message to the master daemon message file.

If message is missing then an empty line will be printed.

jsv_log_warning(message)

This function sends a warning message to the client or master daemon instance that started the JSV script.

For client JSVs, this means that the command line client will get the information and print it to the stdout stream. Server JSVs will print that message as a warning message to the master daemon message file.

If message is missing then an empty line will be printed.

jsv_log_error(message)

This function sends an error message to the client or master daemon instance that started the JSV script.

For client JSVs, this means that the command line client will get the information and print it to the stdout stream. Server JSVs will print that message as an error message to the master daemon message file.

If message is missing then an empty line will be printed.

jsv_send_env()

This function can only be used in jsv_on_start(). If it is used there, then the job environment information will be available in jsv_on_verify() for the next job that is scheduled to be verified.

This function must be called for the functions jsv_show_envs(), jsv_is_env(), jsv_get_env(), jsv_add_env() and jsv_mod_env() to behave correctly.

Job environments might become very big (10kB and more). This will slow down the executing component (submit client or master daemon thread). For this reason, job environment information is not passed to JSV scripts by default.

Please note also that the data in the job environment can't be verified by Grid Engine and might therefore contain values which could be misinterpreted in the script environment and cause security issues.

jsv_main()

This function has to be called in the main function in JSV scripts. It implements the JSV protocol and performs the communication with client and server components which might start JSV scripts.

This function does not return immediately. It returns only when the "QUIT" command is sent by the client or server component.

During the communication with client and server components, this function triggers two callback functions for each job that should be verified. First jsv_on_start() and later on jsv_on_verify().

jsv_on_start() can be used to initialize certain things that might be needed for the verification process. jsv_on_verify() does the verification process itself.

The function jsv_send_env() can be called in jsv_on_start() so that the job environment is available in jsv_on_verify().

The following functions can only be used in jsv_on_verify(). Simple job parameters can be accessed/modified with: jsv_is_param, jsv_get_param, jsv_set_param and jsv_del_param.

List based job parameters can be accessed with: jsv_sub_is_param, jsv_sub_get_param, jsv_sub_add_param and jsv_sub_del_param.

If the environment was requested with jsv_send_env() in jsv_on_start() then the environment can be accessed/modified with the following commands: jsv_is_env, jsv_get_env, jsv_add_env, jsv_mod_env and jsv_del_env.

Jobs can be accepted/rejected with the following: jsv_accept, jsv_correct, jsv_reject and jsv_reject_wait.

The following functions send messages to the calling component of a JSV that will either appear on the stdout stream of the client or in the master message file. This is especially useful when new JSV scripts should be tested: jsv_show_params, jsv_show_envs, jsv_log_info, jsv_log_warning and jsv_log_error.

jsv_on_start()

This is a callback function that has to be defined by the creator of a JSV script. It is called for every job a short time before the verification process of a job starts.

Within this function jsv_send_env can be called to request job environment information for the next job scheduled to be verified.

After this function returns jsv_on_verify() will be called. This function does the verification process itself.

jsv_on_verify()

This is a callback function that has to be defined by the creator of a JSV script. It is called for every job, and when it returns the job will either be accepted or rejected. Find implementation examples in the directory $SGE_ROOT/util/resources/jsv.

The logic of this function completely depends on its creator. The creator has only to take care that one of the functions jsv_accept(), jsv_reject(), jsv_reject_wait() or jsv_correct() is called before the function returns.

jsv_logging_enabled

Setting this variable to true produces logging output tracing the JSV protocol, sent to a file of the form /tmp/jsv_$$.log. In the case of shell JSVs, it may be set in the environment of the job submission to effect logging without modifying the script.

EXAMPLES

Find in the table below the returned values for the "*is*" and "*get*" functions when following job is submitted:

qsub -l mem=1G,mem2=200M -l a=lx-amd64 ...

function call	returned value
jsv_is_param(l_hard)	"true"
jsv_get_param(l_hard)	"mem=1G,mem2=200M,a=lx-amd64"
jsv_sub_is_param(l_hard,mem)	"true"
jsv_sub_get_param(l_hard,mem)	"1G"
jsv_sub_is_param(l_hard,mem3)	"false"
jsv_sub_get_param(l_hard,mem3)	""
jsv_sub_is_param(l_hard,a)	"true"
jsv_sub_get_param(l_hard,a)	"lx-amd64"
jsv_sub_is_param(l_hard,arch)	"false"
jsv_sub_get_param(l_hard,arch)	""

FILES

Include files:
$SGE_ROOT/util/resources/jsv/jsv_include.sh
$SGE_ROOT/util/resources/jsv/jsv_include.tcl
$SGE_ROOT/util/resources/jsv/JSV.pm
Example files:
$SGE_ROOT/util/resources/jsv/jsv.sh
$SGE_ROOT/util/resources/jsv/jsv.tcl
$SGE_ROOT/util/resources/jsv/jsv.pl
$SGE_ROOT/util/resources/jsv/jjsv.sh
$SGE_ROOT/util/resources/jsv/SimpleJsv.java

Debugging log file:
/tmp/jsv_$$.log

BUGS

Complex names seen by the script are not canonicalized, i.e. if the name and shortcut vary, it is necessary to consider both.

COPYRIGHT

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