NAME
drmaa_init, drmaa_exit - Start/finish Grid Engine DRMAA session
SYNOPSIS
#include "drmaa.h"
int drmaa_init(
const char
*contact,
char *error_diagnosis,
size_t error_diag_len
);
int drmaa_exit(
char
*error_diagnosis,
size_t error_diag_len
);
DESCRIPTION
drmaa_init()
The drmaa_init() function initializes the Grid Engine DRMAA
API library for all threads of the process and creates a new
DRMAA session. This routine must be called once before any
other DRMAA call, except for drmaa_version(3),
drmaa_get_DRM_system(3), and
drmaa_get_DRMAA_implementation(3). Except for the
above listed functions, no DRMAA functions may be called
before the drmaa_init() function completes. Any DRMAA
function which is called before the drmaa_init() function
completes will return a DRMAA_ERRNO_NO_ACTIVE_SESSION error.
Contact is an implementation dependent string which
may be used to specify which Grid Engine cell to use. If
contact is NULL, the default Grid Engine cell will be
used. In the 1.0 implementation contact may have the
following value: session=session_id. To
determine the session_id, the
drmaa_get_contact(3) function should be called after
the session has already been initialized. By passing the
session=session_id string to the
drmaa_init() function, instead of creating a new session,
DRMAA will attempt to reconnect to the session indicated by
the session_id. The result of reconnecting to
a previous session is that all jobs previously submitted in
that session that are still running will be available in the
DRMAA session. Note, however, that jobs which ended before
the call to drmaa_init() may not be available or may have no
associated exit information or resource usage data.
drmaa_exit()
The drmaa_exit() function closes the DRMAA session for all
threads and must be called before process termination. The
drmaa_exit() function may be called only once by a single
thread in the process and may only be called after the
drmaa_init() function has completed. Any DRMAA function,
other than drmaa_init(3), which is called after the
drmaa_exit() function completes will return a
DRMAA_ERRNO_NO_ACTIVE_SESSION error.
The drmaa_exit() function does necessary clean up of the DRMAA session state, including unregistering from the qmaster(8). If the drmaa_exit() function is not called, the qmaster will store events for the DRMAA client until the connection times out, causing extra work for the qmaster and consuming system resources.
Submitted jobs are not affected by the drmaa_exit() function.
ENVIRONMENTAL VARIABLES
|
SGE_ROOT |
Specifies the location of the Grid Engine standard configuration files. | ||
|
SGE_CELL |
If set, specifies the default Grid Engine cell to be used. To address a Grid Engine cell Grid Engine uses (in the order of precedence): |
The name of the cell specified in the environment variable SGE_CELL, if it is set.
The name of the default cell, i.e. default.
SGE_DEBUG_LEVEL
If set, specifies that debug information should be written to stderr. In addition the level of detail in which debug information is generated is defined.
SGE_QMASTER_PORT
If set, specifies the tcp port on which the sge_qmaster is expected to listen for communication requests. Most installations will use a services map entry instead to define that port.
RETURN VALUES
Upon successful completion, drmaa_init() and drmaa_exit() return DRMAA_ERRNO_SUCCESS. Other values indicate an error. Up to error_diag_len characters of error related diagnosis information is then provided in the buffer error_diagnosis.
ERRORS
The
drmaa_init() and drmaa_exit() functions can fail with:
DRMAA_ERRNO_INTERNAL_ERROR
Unexpected or internal DRMAA error, like system call failure, etc.
DRMAA_ERRNO_DRM_COMMUNICATION_FAILURE
Could not contact DRM system for this request.
DRMAA_ERRNO_AUTH_FAILURE
The specified request is not processed successfully due to authorization failure.
DRMAA_ERRNO_INVALID_ARGUMENT
The input value for an argument is invalid.
The
drmaa_init() function can fail with:
DRMAA_ERRNO_INVALID_CONTACT_STRING
Initialization failed due to invalid contact string.
DRMAA_ERRNO_DEFAULT_CONTACT_STRING_ERROR
Could not use the default contact string to connect to DRM system.
DRMAA_ERRNO_DRMS_INIT_FAILED
Initialization failed due to failure to init DRM system.
DRMAA_ERRNO_ALREADY_ACTIVE_SESSION
Initialization failed due to existing DRMAA session.
DRMAA_ERRNO_NO_MEMORY
Failed allocating memory.
The
drmaa_exit() function can fail with:
DRMAA_ERRNO_NO_ACTIVE_SESSION
Failed because there is no active session.
DRMAA_ERRNO_DRMS_EXIT_ERROR
DRM system disengagement failed.