work_queue.h File Reference

A master-worker library. More...

#include <sys/types.h>
#include "timestamp.h"
#include "rmsummary.h"

Go to the source code of this file.

Data Structures

struct  work_queue_task
 A task description. More...
struct  work_queue_stats
 Statistics describing a work queue. More...

Defines

#define WORK_QUEUE_DEFAULT_PORT   9123
 Default Work Queue port number.
#define WORK_QUEUE_RANDOM_PORT   0
 Indicates that any port number may be chosen.
#define WORK_QUEUE_WAITFORTASK   -1
 Wait for a task to complete before returning.
#define WORK_QUEUE_SCHEDULE_FCFS   1
 Select worker on a first-come-first-serve basis.
#define WORK_QUEUE_SCHEDULE_FILES   2
 Select worker that has the most data required by the task.
#define WORK_QUEUE_SCHEDULE_TIME   3
 Select worker that has the fastest execution time on previous tasks.
#define WORK_QUEUE_SCHEDULE_RAND   4
 Select a random worker.
#define WORK_QUEUE_INPUT   0
 Specify an input object.
#define WORK_QUEUE_OUTPUT   1
 Specify an output object.
#define WORK_QUEUE_NOCACHE   0
 Do not cache file at execution site.
#define WORK_QUEUE_CACHE   1
 Cache file at execution site for later use.
#define WORK_QUEUE_WATCH   16
 Watch the output file and send back changes as the task runs.
#define WORK_QUEUE_RESET_ALL   0
 When resetting, clear out all tasks and files.
#define WORK_QUEUE_RESET_KEEP_TASKS   1
 When resetting, keep the current list of tasks.
#define WORK_QUEUE_DEFAULT_KEEPALIVE_INTERVAL   300
 Default value for Work Queue keepalive interval in seconds.
#define WORK_QUEUE_DEFAULT_KEEPALIVE_TIMEOUT   30
 Default value for Work Queue keepalive timeout in seconds.
#define WORK_QUEUE_RESULT_SUCCESS   0
 The task ran successfully >.
#define WORK_QUEUE_RESULT_INPUT_MISSING   1
 The task cannot be run due to a missing input file >.
#define WORK_QUEUE_RESULT_OUTPUT_MISSING   2
 The task ran but failed to generate a specified output file >.
#define WORK_QUEUE_RESULT_STDOUT_MISSING   4
 The task ran but its stdout has been truncated >.
#define WORK_QUEUE_RESULT_SIGNAL   8
 The task was terminated with a signal >.
#define WORK_QUEUE_RESULT_RESOURCE_EXHAUSTION   16
 The task used more resources than requested >.
#define WORK_QUEUE_RESULT_TASK_TIMEOUT   32
 The task ran after specified end time.
#define WORK_QUEUE_TASK_UNKNOWN   0
 Task states.
#define WORK_QUEUE_TASK_READY   1
 Task is ready to be run, waiting in queue >.
#define WORK_QUEUE_TASK_RUNNING   2
 Task has been dispatched to some worker >.
#define WORK_QUEUE_TASK_WAITING_RETRIEVAL   3
 Task results are available at the worker >.
#define WORK_QUEUE_TASK_RETRIEVED   4
 Task results are available at the master >.
#define WORK_QUEUE_TASK_DONE   5
 Task is done, and has been returned through work_queue_wait >.
#define WORK_QUEUE_TASK_CANCELED   6
 Task was canceled before completion >.

Functions

Functions - Tasks



struct work_queue_taskwork_queue_task_create (const char *full_command)
 Create a new task object.
struct work_queue_taskwork_queue_task_clone (const struct work_queue_task *task)
 Create a copy of a task Create a functionally identical copy of a work_queue_task that can be re-submitted via work_queue_submit.
void work_queue_task_specify_command (struct work_queue_task *t, const char *cmd)
 Indicate the command to be executed.
int work_queue_task_specify_file (struct work_queue_task *t, const char *local_name, const char *remote_name, int type, int flags)
 Add a file to a task.
int work_queue_task_specify_file_piece (struct work_queue_task *t, const char *local_name, const char *remote_name, off_t start_byte, off_t end_byte, int type, int flags)
 Add a file piece to a task.
int work_queue_task_specify_buffer (struct work_queue_task *t, const char *data, int length, const char *remote_name, int flags)
 Add an input buffer to a task.
int work_queue_task_specify_directory (struct work_queue_task *t, const char *local_name, const char *remote_name, int type, int flags, int recursive)
 Add a directory to a task.
void work_queue_task_specify_memory (struct work_queue_task *t, int64_t memory)
 Specify the amount of memory required by a task.
void work_queue_task_specify_disk (struct work_queue_task *t, int64_t disk)
 Specify the amount of disk space required by a task.
void work_queue_task_specify_cores (struct work_queue_task *t, int cores)
 Specify the number of cores required by a task.
void work_queue_task_specify_gpus (struct work_queue_task *t, int gpus)
 Specify the number of gpus required by a task.
void work_queue_task_specify_end_time (struct work_queue_task *t, int64_t seconds)
 Specify the maximum end time allowed for the task (in seconds since the Epoch).
void work_queue_task_specify_tag (struct work_queue_task *t, const char *tag)
 Attach a user defined string tag to the task.
void work_queue_task_specify_priority (struct work_queue_task *t, double priority)
 Specify the priority of this task relative to others in the queue.
void work_queue_task_specify_algorithm (struct work_queue_task *t, int algo)
 Select the scheduling algorithm for a single task.
void work_queue_task_delete (struct work_queue_task *t)
 Delete a task.
Functions - Queues



struct work_queue * work_queue_create (int port)
 Create a new work queue.
int work_queue_enable_monitoring (struct work_queue *q, char *monitor_summary_file)
 Enables resource monitoring on the give work queue.
int work_queue_submit (struct work_queue *q, struct work_queue_task *t)
 Submit a task to a queue.
void work_queue_blacklist_add (struct work_queue *q, const char *hostname)
 Blacklist host from a queue.
void work_queue_blacklist_remove (struct work_queue *q, const char *hostname)
 Unblacklist host from a queue.
void work_queue_blacklist_clear (struct work_queue *q)
 Clear blacklist of a queue.
struct work_queue_taskwork_queue_wait (struct work_queue *q, int timeout)
 Wait for a task to complete.
int work_queue_hungry (struct work_queue *q)
 Determine whether the queue is 'hungry' for more tasks.
int work_queue_empty (struct work_queue *q)
 Determine whether the queue is empty.
int work_queue_port (struct work_queue *q)
 Get the listening port of the queue.
void work_queue_get_stats (struct work_queue *q, struct work_queue_stats *s)
 Get queue statistics (only from master).
void work_queue_get_stats_hierarchy (struct work_queue *q, struct work_queue_stats *s)
 Get statistics of the master queue together with foremen information.
int work_queue_task_state (struct work_queue *q, int taskid)
 Get the current state of the task.
void work_queue_set_bandwidth_limit (struct work_queue *q, const char *bandwidth)
 Limit the queue bandwidth when transferring files to and from workers.
double work_queue_get_effective_bandwidth (struct work_queue *q)
 Get current queue bandwidth.
char * work_queue_get_worker_summary (struct work_queue *q)
 Summarize workers.
int work_queue_activate_fast_abort (struct work_queue *q, double multiplier)
 Turn on or off fast abort functionality for a given queue.
int work_queue_send_receive_ratio (struct work_queue *q, double ratio)
 Change the preference to send or receive tasks.
void work_queue_specify_algorithm (struct work_queue *q, int algo)
 Change the worker selection algorithm.
const char * work_queue_name (struct work_queue *q)
 Get the project name of the queue.
void work_queue_specify_name (struct work_queue *q, const char *name)
 Change the project name for a given queue.
void work_queue_specify_priority (struct work_queue *q, int priority)
 Change the priority for a given queue.
void work_queue_specify_catalog_server (struct work_queue *q, const char *hostname, int port)
 Specify the catalog server the master should report to.
struct work_queue_taskwork_queue_cancel_by_taskid (struct work_queue *q, int id)
 Cancel a submitted task using its task id and remove it from queue.
struct work_queue_taskwork_queue_cancel_by_tasktag (struct work_queue *q, const char *tag)
 Cancel a submitted task using its tag and remove it from queue.
struct listwork_queue_cancel_all_tasks (struct work_queue *q)
 Cancel all submitted tasks and remove them from the queue.
int work_queue_shut_down_workers (struct work_queue *q, int n)
 Shut down workers connected to the work_queue system.
void work_queue_delete (struct work_queue *q)
 Delete a work queue.
int work_queue_specify_log (struct work_queue *q, const char *logfile)
 Add a log file that records the states of the connected workers and submitted tasks.
void work_queue_specify_password (struct work_queue *q, const char *password)
 Add a mandatory password that each worker must present.
int work_queue_specify_password_file (struct work_queue *q, const char *file)
 Add a mandatory password file that each worker must present.
void work_queue_specify_keepalive_interval (struct work_queue *q, int interval)
 Change the keepalive interval for a given queue.
void work_queue_specify_keepalive_timeout (struct work_queue *q, int timeout)
 Change the keepalive timeout for identifying dead workers for a given queue.
int work_queue_tune (struct work_queue *q, const char *name, double value)
 Tune advanced parameters for work queue.

Variables

double wq_option_fast_abort_multiplier
 Initial setting for fast abort multiplier upon creating queue.
int wq_option_scheduler
 Initial setting for algorithm to assign tasks to workers upon creating queue .

Functions - Deprecated



#define WORK_QUEUE_TASK_ORDER_FIFO   0
 Retrieve tasks based on first-in-first-out order.
#define WORK_QUEUE_TASK_ORDER_LIFO   1
 Retrieve tasks based on last-in-first-out order.
#define WORK_QUEUE_MASTER_MODE_STANDALONE   0
 Work Queue master does not report to the catalog server.
#define WORK_QUEUE_MASTER_MODE_CATALOG   1
 Work Queue master reports to catalog server.
void work_queue_specify_task_order (struct work_queue *q, int order)
 Specified how the submitted tasks should be ordered.
void work_queue_specify_master_mode (struct work_queue *q, int mode)
 Specify the master mode for a given queue.
void work_queue_specify_estimate_capacity_on (struct work_queue *q, int estimate_capacity_on)
 Change whether to estimate master capacity for a given queue.
int work_queue_task_specify_input_buf (struct work_queue_task *t, const char *buf, int length, const char *rname)
 Add an input buffer to a task.
int work_queue_task_specify_input_file (struct work_queue_task *t, const char *fname, const char *rname)
 Add an input file to a task.
int work_queue_task_specify_input_file_do_not_cache (struct work_queue_task *t, const char *fname, const char *rname)
 Add an input file to a task, without caching.
int work_queue_task_specify_output_file (struct work_queue_task *t, const char *rname, const char *fname)
 Add an output file to a task.
int work_queue_task_specify_output_file_do_not_cache (struct work_queue_task *t, const char *rname, const char *fname)
 Add an output file to a task without caching.

Detailed Description

A master-worker library.

The work queue provides an implementation of the master-worker computing model using TCP sockets, Unix applications, and files as intermediate buffers. A master process uses work_queue_create to create a queue, then work_queue_submit to submit tasks. Once tasks are running, call work_queue_wait to wait for completion. A generic worker program, named work_queue_worker, can be run on any machine, and simply needs to be told the host and port of the master.


Define Documentation

#define WORK_QUEUE_DEFAULT_PORT   9123

Default Work Queue port number.

#define WORK_QUEUE_RANDOM_PORT   0

Indicates that any port number may be chosen.

#define WORK_QUEUE_WAITFORTASK   -1

Wait for a task to complete before returning.

#define WORK_QUEUE_SCHEDULE_FCFS   1

Select worker on a first-come-first-serve basis.

#define WORK_QUEUE_SCHEDULE_FILES   2

Select worker that has the most data required by the task.

#define WORK_QUEUE_SCHEDULE_TIME   3

Select worker that has the fastest execution time on previous tasks.

#define WORK_QUEUE_SCHEDULE_RAND   4

Select a random worker.

(default)

#define WORK_QUEUE_INPUT   0

Specify an input object.

#define WORK_QUEUE_OUTPUT   1

Specify an output object.

#define WORK_QUEUE_NOCACHE   0

Do not cache file at execution site.

#define WORK_QUEUE_CACHE   1

Cache file at execution site for later use.

#define WORK_QUEUE_WATCH   16

Watch the output file and send back changes as the task runs.

#define WORK_QUEUE_RESET_ALL   0

When resetting, clear out all tasks and files.

#define WORK_QUEUE_RESET_KEEP_TASKS   1

When resetting, keep the current list of tasks.

#define WORK_QUEUE_DEFAULT_KEEPALIVE_INTERVAL   300

Default value for Work Queue keepalive interval in seconds.

#define WORK_QUEUE_DEFAULT_KEEPALIVE_TIMEOUT   30

Default value for Work Queue keepalive timeout in seconds.

#define WORK_QUEUE_RESULT_SUCCESS   0

The task ran successfully >.

#define WORK_QUEUE_RESULT_INPUT_MISSING   1

The task cannot be run due to a missing input file >.

#define WORK_QUEUE_RESULT_OUTPUT_MISSING   2

The task ran but failed to generate a specified output file >.

#define WORK_QUEUE_RESULT_STDOUT_MISSING   4

The task ran but its stdout has been truncated >.

#define WORK_QUEUE_RESULT_SIGNAL   8

The task was terminated with a signal >.

#define WORK_QUEUE_RESULT_RESOURCE_EXHAUSTION   16

The task used more resources than requested >.

#define WORK_QUEUE_RESULT_TASK_TIMEOUT   32

The task ran after specified end time.

>

#define WORK_QUEUE_TASK_UNKNOWN   0

Task states.

There is no such task >

#define WORK_QUEUE_TASK_READY   1

Task is ready to be run, waiting in queue >.

#define WORK_QUEUE_TASK_RUNNING   2

Task has been dispatched to some worker >.

#define WORK_QUEUE_TASK_WAITING_RETRIEVAL   3

Task results are available at the worker >.

#define WORK_QUEUE_TASK_RETRIEVED   4

Task results are available at the master >.

#define WORK_QUEUE_TASK_DONE   5

Task is done, and has been returned through work_queue_wait >.

#define WORK_QUEUE_TASK_CANCELED   6

Task was canceled before completion >.

#define WORK_QUEUE_TASK_ORDER_FIFO   0

Retrieve tasks based on first-in-first-out order.

#define WORK_QUEUE_TASK_ORDER_LIFO   1

Retrieve tasks based on last-in-first-out order.

#define WORK_QUEUE_MASTER_MODE_STANDALONE   0

Work Queue master does not report to the catalog server.

#define WORK_QUEUE_MASTER_MODE_CATALOG   1

Work Queue master reports to catalog server.


Function Documentation

struct work_queue_task* work_queue_task_create ( const char *  full_command  )  [read]

Create a new task object.

Once created and elaborated with functions such as work_queue_task_specify_file and work_queue_task_specify_buffer, the task should be passed to work_queue_submit.

Parameters:
full_command The shell command line to be executed by the task. If null, the command will be given later by work_queue_task_specify_command
Returns:
A new task object, or null if it could not be created.
struct work_queue_task* work_queue_task_clone ( const struct work_queue_task task  )  [read]

Create a copy of a task Create a functionally identical copy of a work_queue_task that can be re-submitted via work_queue_submit.

Returns:
A new task object
void work_queue_task_specify_command ( struct work_queue_task t,
const char *  cmd 
)

Indicate the command to be executed.

Parameters:
t A task object.
cmd The command to be executed. This string will be duplicated by this call, so the argument may be freed or re-used afterward.
int work_queue_task_specify_file ( struct work_queue_task t,
const char *  local_name,
const char *  remote_name,
int  type,
int  flags 
)

Add a file to a task.

Parameters:
t A task object.
local_name The name of the file on local disk or shared filesystem.
remote_name The name of the file at the remote execution site.
type Must be one of the following values:

flags May be zero to indicate no special handling or any of the following or'd together:

  • WORK_QUEUE_CACHE indicates that the file should be cached for later tasks. (recommended)
  • WORK_QUEUE_NOCACHE indicates that the file should not be cached for later tasks.
  • WORK_QUEUE_WATCH indicates that the worker will watch the output file as it is created and incrementally return the file to the master as the task runs. (The frequency of these updates is entirely dependent upon the system load. If the master is busy interacting with many workers, output updates will be infrequent.)
Returns:
1 if the task file is successfully specified, 0 if either of t, local_name, or remote_name is null or remote_name is an absolute path.
int work_queue_task_specify_file_piece ( struct work_queue_task t,
const char *  local_name,
const char *  remote_name,
off_t  start_byte,
off_t  end_byte,
int  type,
int  flags 
)

Add a file piece to a task.

Parameters:
t A task object.
local_name The name of the file on local disk or shared filesystem.
remote_name The name of the file at the remote execution site.
start_byte The starting byte offset of the file piece to be transferred.
end_byte The ending byte offset of the file piece to be transferred.
type Must be one of the following values:

flags May be zero to indicate no special handling or any of the following or'd together:

  • WORK_QUEUE_CACHE indicates that the file should be cached for later tasks. (recommended)
  • WORK_QUEUE_NOCACHE indicates that the file should not be cached for later tasks.
Returns:
1 if the task file piece is successfully specified, 0 if either of t, local_name, or remote_name is null or remote_name is an absolute path.
int work_queue_task_specify_buffer ( struct work_queue_task t,
const char *  data,
int  length,
const char *  remote_name,
int  flags 
)

Add an input buffer to a task.

Parameters:
t A task object.
data The data to be passed as an input file.
length The length of the buffer, in bytes
remote_name The name of the remote file to create.
flags May be zero to indicate no special handling or any of the following or'd together:

  • WORK_QUEUE_CACHE indicates that the file should be cached for later tasks. (recommended)
  • WORK_QUEUE_NOCACHE indicates that the file should not be cached for later tasks.
Returns:
1 if the task file is successfully specified, 0 if either of t or remote_name is null or remote_name is an absolute path.
int work_queue_task_specify_directory ( struct work_queue_task t,
const char *  local_name,
const char *  remote_name,
int  type,
int  flags,
int  recursive 
)

Add a directory to a task.

Parameters:
t A task object.
local_name The name of the directory on local disk or shared filesystem. Optional if the directory is empty.
remote_name The name of the directory at the remote execution site.
type Must be one of the following values:

flags May be zero to indicate no special handling or any of the following or'd together:

  • WORK_QUEUE_CACHE indicates that the file should be cached for later tasks. (recommended)
  • WORK_QUEUE_NOCACHE indicates that the file should not be cached for later tasks.
recursive indicates whether just the directory (0) or the directory and all of its contents (1) should be included.
Returns:
1 if the task directory is successfully specified, 0 if either of t, local_name, or remote_name is null or remote_name is an absolute path.
void work_queue_task_specify_memory ( struct work_queue_task t,
int64_t  memory 
)

Specify the amount of memory required by a task.

Parameters:
t A task object.
memory The amount of memory required by the task, in megabytes.
void work_queue_task_specify_disk ( struct work_queue_task t,
int64_t  disk 
)

Specify the amount of disk space required by a task.

Parameters:
t A task object.
disk The amount of disk space required by the task, in megabytes.
void work_queue_task_specify_cores ( struct work_queue_task t,
int  cores 
)

Specify the number of cores required by a task.

Parameters:
t A task object.
cores The number of cores required by the task.
void work_queue_task_specify_gpus ( struct work_queue_task t,
int  gpus 
)

Specify the number of gpus required by a task.

Parameters:
t A task object.
gpus The number of gpus required by the task.
void work_queue_task_specify_end_time ( struct work_queue_task t,
int64_t  seconds 
)

Specify the maximum end time allowed for the task (in seconds since the Epoch).

If seconds less than 1, then no end time is specified.

Parameters:
t A task object.
seconds Number of seconds since the Epoch.
void work_queue_task_specify_tag ( struct work_queue_task t,
const char *  tag 
)

Attach a user defined string tag to the task.

This field is not interpreted by the work queue, but is provided for the user's convenience in identifying tasks when they complete.

Parameters:
t A task object.
tag The tag to attach to task t.
void work_queue_task_specify_priority ( struct work_queue_task t,
double  priority 
)

Specify the priority of this task relative to others in the queue.

Tasks with a higher priority value run first. If no priority is given, a task is placed at the end of the ready list, regardless of the priority.

Parameters:
t A task object.
priority The priority of the task.
void work_queue_task_specify_algorithm ( struct work_queue_task t,
int  algo 
)

Select the scheduling algorithm for a single task.

To change the scheduling algorithm for all tasks, use work_queue_specify_algorithm instead.

Parameters:
t A task object.
algo The algorithm to use in assigning this task to a worker:

void work_queue_task_delete ( struct work_queue_task t  ) 

Delete a task.

This may be called on tasks after they are returned from work_queue_wait.

Parameters:
t The task to delete.
struct work_queue* work_queue_create ( int  port  )  [read]

Create a new work queue.

Users may modify the behavior of work_queue_create by setting the following environmental variables before calling the function:

  • WORK_QUEUE_PORT: This sets the default port of the queue (if unset, the default is 9123).
  • WORK_QUEUE_LOW_PORT: If the user requests a random port, then this sets the first port number in the scan range (if unset, the default is 1024).
  • WORK_QUEUE_HIGH_PORT: If the user requests a random port, then this sets the last port number in the scan range (if unset, the default is 32767).
  • WORK_QUEUE_NAME: This sets the project name of the queue, which is reported to a catalog server (by default this is unset).
  • WORK_QUEUE_PRIORITY: This sets the priority of the queue, which is used by workers to sort masters such that higher priority masters will be served first (if unset, the default is 10).

If the queue has a project name, then queue statistics and information will be reported to a catalog server. To specify the catalog server, the user may set the CATALOG_HOST and CATALOG_PORT environmental variables as described in catalog_query_create.

Parameters:
port The port number to listen on. If zero is specified, then the port stored in the WORK_QUEUE_PORT environment variable is used if available. If it isn't, or if -1 is specified, the first unused port between WORK_QUEUE_LOW_PORT and WORK_QUEUE_HIGH_PORT (1024 and 32767 by default) is chosen.
Returns:
A new work queue, or null if it could not be created.
int work_queue_enable_monitoring ( struct work_queue *  q,
char *  monitor_summary_file 
)

Enables resource monitoring on the give work queue.

It generates the log file indicated by monitor_summary_file with all the summaries of the resources used by each task.

Parameters:
q A work queue object.
monitor_summary_file The filename of the log (If NULL, it defaults to wq-pid-resource-usage).
Returns:
1 on success, 0 if monitoring was not enabled.
int work_queue_submit ( struct work_queue *  q,
struct work_queue_task t 
)

Submit a task to a queue.

Once a task is submitted to a queue, it is not longer under the user's control and should not be inspected until returned via work_queue_wait. Once returned, it is safe to re-submit the same take object via work_queue_submit.

Parameters:
q A work queue object.
t A task object returned from work_queue_task_create.
Returns:
An integer taskid assigned to the submitted task.
void work_queue_blacklist_add ( struct work_queue *  q,
const char *  hostname 
)

Blacklist host from a queue.

Parameters:
q A work queue object.
hostname A string for hostname.
void work_queue_blacklist_remove ( struct work_queue *  q,
const char *  hostname 
)

Unblacklist host from a queue.

Parameters:
q A work queue object.
hostname A string for hostname.
void work_queue_blacklist_clear ( struct work_queue *  q  ) 

Clear blacklist of a queue.

Parameters:
q A work queue object.
struct work_queue_task* work_queue_wait ( struct work_queue *  q,
int  timeout 
) [read]

Wait for a task to complete.

This call will block until either a task has completed, the timeout has expired, or the queue is empty. If a task has completed, the corresponding task object will be returned by this function. The caller may examine the task and then dispose of it using work_queue_task_delete.

If the task ran to completion, then the result field will be zero and the return_status field will contain the Unix exit code of the task. If the task could not, then the result field will be non-zero and the return_status field will be undefined.

Parameters:
q A work queue object.
timeout The number of seconds to wait for a completed task before returning. Use an integer time to set the timeout or the constant WORK_QUEUE_WAITFORTASK to block until a task has completed.
Returns:
A completed task description, or null if the queue is empty, or the timeout was reached without a completed task, or there is completed child process (call process_wait to retrieve the status of the completed child process).
int work_queue_hungry ( struct work_queue *  q  ) 

Determine whether the queue is 'hungry' for more tasks.

While the Work Queue can handle a very large number of tasks, it runs most efficiently when the number of tasks is slightly larger than the number of active workers. This function gives the user of a flexible application a hint about whether it would be better to submit more tasks via work_queue_submit or wait for some to complete via work_queue_wait.

Parameters:
q A work queue object.
Returns:
The number of additional tasks that can be efficiently submitted, or zero if the queue has enough to work with right now.
int work_queue_empty ( struct work_queue *  q  ) 

Determine whether the queue is empty.

When all of the desired tasks have been submitted to the queue, the user should continue to call work_queue_wait until this function returns true.

Parameters:
q A work queue object.
Returns:
True if the queue is completely empty, false otherwise.
int work_queue_port ( struct work_queue *  q  ) 

Get the listening port of the queue.

As noted in work_queue_create, there are many controls that affect what TCP port the queue will listen on. Rather than assuming a specific port, the user should simply call this function to determine what port was selected.

Parameters:
q A work queue object.
Returns:
The port the queue is listening on.
void work_queue_get_stats ( struct work_queue *  q,
struct work_queue_stats s 
)

Get queue statistics (only from master).

Parameters:
q A work queue object.
s A pointer to a buffer that will be filed with statistics.
void work_queue_get_stats_hierarchy ( struct work_queue *  q,
struct work_queue_stats s 
)

Get statistics of the master queue together with foremen information.

Parameters:
q A work queue object.
s A pointer to a buffer that will be filed with statistics.
int work_queue_task_state ( struct work_queue *  q,
int  taskid 
)

Get the current state of the task.

Parameters:
q A work queue object.
taskid The taskid of the task.
Returns:
One of: WORK_QUEUE_TASK(UNKNOWN|READY|RUNNING|RESULTS|RETRIEVED|DONE)
void work_queue_set_bandwidth_limit ( struct work_queue *  q,
const char *  bandwidth 
)

Limit the queue bandwidth when transferring files to and from workers.

Parameters:
q A work queue object.
bandwidth The bandwidth limit in bytes per second.
double work_queue_get_effective_bandwidth ( struct work_queue *  q  ) 

Get current queue bandwidth.

Parameters:
q A work queue object.
Returns:
The average bandwidth in MB/s measured by the master.
char* work_queue_get_worker_summary ( struct work_queue *  q  ) 

Summarize workers.

This function summarizes the workers currently connected to the master, indicating how many from each worker pool are attached.

Parameters:
q A work queue object.
Returns:
A newly allocated string describing the distribution of workers by pool. The caller must release this string via free().
int work_queue_activate_fast_abort ( struct work_queue *  q,
double  multiplier 
)

Turn on or off fast abort functionality for a given queue.

Parameters:
q A work queue object.
multiplier The multiplier of the average task time at which point to abort; if negative (and by default) fast_abort is deactivated.
Returns:
0 if activated or deactivated with an appropriate multiplier, 1 if deactivated due to inappropriate multiplier.
int work_queue_send_receive_ratio ( struct work_queue *  q,
double  ratio 
)

Change the preference to send or receive tasks.

Parameters:
q A work queue object.
ratio The send/receive ratio when there is a choice between sending and receiving tasks. 1 Always prefer to send (e.g., for homogenous, stable resources). 0 Always prefer to receive (e.g., for resources with hight rate of eviction). Default is 0.75 (one average, receive one task per three sent).
void work_queue_specify_algorithm ( struct work_queue *  q,
int  algo 
)

Change the worker selection algorithm.

This function controls which worker will be selected for a given task.

Parameters:
q A work queue object.
algo The algorithm to use in assigning a task to a worker:

const char* work_queue_name ( struct work_queue *  q  ) 

Get the project name of the queue.

Parameters:
q A work queue object.
Returns:
The project name of the queue.
void work_queue_specify_name ( struct work_queue *  q,
const char *  name 
)

Change the project name for a given queue.

Parameters:
q A work queue object.
name The new project name.
void work_queue_specify_priority ( struct work_queue *  q,
int  priority 
)

Change the priority for a given queue.

Parameters:
q A work queue object.
priority The new priority of the queue. Higher priority masters will attract workers first.
void work_queue_specify_catalog_server ( struct work_queue *  q,
const char *  hostname,
int  port 
)

Specify the catalog server the master should report to.

Parameters:
q A work queue object.
hostname The catalog server's hostname.
port The port the catalog server is listening on.
struct work_queue_task* work_queue_cancel_by_taskid ( struct work_queue *  q,
int  id 
) [read]

Cancel a submitted task using its task id and remove it from queue.

Parameters:
q A work queue object.
id The taskid returned from work_queue_submit.
Returns:
The task description of the cancelled task, or null if the task was not found in queue. The returned task must be deleted with work_queue_task_delete or resubmitted with work_queue_submit.
struct work_queue_task* work_queue_cancel_by_tasktag ( struct work_queue *  q,
const char *  tag 
) [read]

Cancel a submitted task using its tag and remove it from queue.

Parameters:
q A work queue object.
tag The tag name assigned to task using work_queue_task_specify_tag.
Returns:
The task description of the cancelled task, or null if the task was not found in queue. The returned task must be deleted with work_queue_task_delete or resubmitted with work_queue_submit.
struct list* work_queue_cancel_all_tasks ( struct work_queue *  q  )  [read]

Cancel all submitted tasks and remove them from the queue.

Parameters:
q A work queue object.
Returns:
A list of all of the tasks submitted to q. Each task must be deleted with work_queue_task_delete or resubmitted with work_queue_submit.
int work_queue_shut_down_workers ( struct work_queue *  q,
int  n 
)

Shut down workers connected to the work_queue system.

Gives a best effort and then returns the number of workers given the shut down order.

Parameters:
q A work queue object.
n The number to shut down. All workers if given "0".
void work_queue_delete ( struct work_queue *  q  ) 

Delete a work queue.

This function should only be called after work_queue_empty returns true.

Parameters:
q A work queue to delete.
int work_queue_specify_log ( struct work_queue *  q,
const char *  logfile 
)

Add a log file that records the states of the connected workers and submitted tasks.

Parameters:
q A work queue object.
logfile The filename.
Returns:
1 if logfile was opened, 0 otherwise.
void work_queue_specify_password ( struct work_queue *  q,
const char *  password 
)

Add a mandatory password that each worker must present.

Parameters:
q A work queue object.
password The password to require.
int work_queue_specify_password_file ( struct work_queue *  q,
const char *  file 
)

Add a mandatory password file that each worker must present.

Parameters:
q A work queue object.
file The name of the file containing the password.
Returns:
True if the password was loaded, false otherwise.
void work_queue_specify_keepalive_interval ( struct work_queue *  q,
int  interval 
)

Change the keepalive interval for a given queue.

Parameters:
q A work queue object.
interval The minimum number of seconds to wait before sending new keepalive checks to workers.
void work_queue_specify_keepalive_timeout ( struct work_queue *  q,
int  timeout 
)

Change the keepalive timeout for identifying dead workers for a given queue.

Parameters:
q A work queue object.
timeout The minimum number of seconds to wait for a keepalive response from worker before marking it as dead.
int work_queue_tune ( struct work_queue *  q,
const char *  name,
double  value 
)

Tune advanced parameters for work queue.

Parameters:
q A work queue object.
name The name of the parameter to tune

  • "asynchrony-multiplier" Treat each worker as having (actual_cores * multiplier) total cores. (default = 1.0)
  • "asynchrony-modifier" Treat each worker as having an additional "modifier" cores. (default=0)
  • "min-transfer-timeout" Set the minimum number of seconds to wait for files to be transferred to or from a worker. (default=10)
  • "foreman-transfer-timeout" Set the minimum number of seconds to wait for files to be transferred to or from a foreman. (default=3600)
  • "transfer-outlier-factor" Transfer that are this many times slower than the average will be aborted. (default=10x)
  • "default-transfer-rate" The assumed network bandwidth used until sufficient data has been collected. (1MB/s)
  • "fast-abort-multiplier" Set the multiplier of the average task time at which point to abort; if negative or zero fast_abort is deactivated. (default=0)
  • "keepalive-interval" Set the minimum number of seconds to wait before sending new keepalive checks to workers. (default=300)
  • "keepalive-timeout" Set the minimum number of seconds to wait for a keepalive response from worker before marking it as dead. (default=30)
value The value to set the parameter to.
Returns:
0 on succes, -1 on failure.
void work_queue_specify_task_order ( struct work_queue *  q,
int  order 
)

Specified how the submitted tasks should be ordered.

It does not have any effect now.

Parameters:
q A work queue object.
order The ordering to use for dispatching submitted tasks:

void work_queue_specify_master_mode ( struct work_queue *  q,
int  mode 
)

Specify the master mode for a given queue.

Parameters:
q A work queue object.
mode 
Deprecated:
Enabled automatically when work_queue_specify_name is used.
void work_queue_specify_estimate_capacity_on ( struct work_queue *  q,
int  estimate_capacity_on 
)

Change whether to estimate master capacity for a given queue.

Parameters:
q A work queue object.
estimate_capacity_on if the value of this parameter is 1, then work queue should estimate the master capacity. If the value is 0, then work queue would not estimate its master capacity.
Deprecated:
This feature is always enabled.
int work_queue_task_specify_input_buf ( struct work_queue_task t,
const char *  buf,
int  length,
const char *  rname 
)

Add an input buffer to a task.

Parameters:
t The task to which to add parameters
buf A pointer to the data buffer to send to the worker to be available to the commands.
length The number of bytes of data in the buffer
rname The name of the file in which to store the buffer data on the worker
Returns:
1 if the input buffer is successfully specified, 0 if either of t or rname is null or rname is an absolute path.
Deprecated:
Use work_queue_task_specify_buffer instead.
int work_queue_task_specify_input_file ( struct work_queue_task t,
const char *  fname,
const char *  rname 
)

Add an input file to a task.

Parameters:
t The task to which to add parameters
fname The name of the data file to send to the worker to be available to the commands.
rname The name of the file in which to store the buffer data on the worker.
Returns:
1 if the input file is successfully specified, 0 if either of t, fname, or rname is null or rname is an absolute path.
Deprecated:
See work_queue_task_specify_file instead.
int work_queue_task_specify_input_file_do_not_cache ( struct work_queue_task t,
const char *  fname,
const char *  rname 
)

Add an input file to a task, without caching.

Parameters:
t The task to which to add parameters
fname The name of the data file to send to the worker to be available to the commands.
rname The name of the file in which to store the buffer data on the worker.
Returns:
1 if the input file is successfully specified, 0 if either of t, fname, or rname is null or rname is an absolute path.
Deprecated:
See work_queue_task_specify_file instead.
int work_queue_task_specify_output_file ( struct work_queue_task t,
const char *  rname,
const char *  fname 
)

Add an output file to a task.

Parameters:
t The task to which to add parameters
rname The name of a file created by the program when it runs.
fname The name of the file local target for copying rname back.
Returns:
1 if the output file is successfully specified, 0 if either of t, fname, or rname is null or rname is an absolute path.
Deprecated:
See work_queue_task_specify_file instead.
int work_queue_task_specify_output_file_do_not_cache ( struct work_queue_task t,
const char *  rname,
const char *  fname 
)

Add an output file to a task without caching.

Parameters:
t The task to which to add parameters
rname The name of a file created by the program when it runs.
fname The name of the file local target for copying rname back.
Returns:
1 if the output file is successfully specified, 0 if either of t, fname, or rname is null or rname is an absolute path.
Deprecated:
See work_queue_task_specify_file instead.

Variable Documentation

Initial setting for fast abort multiplier upon creating queue.

Turned off if less than 0. Change prior to calling work_queue_create, after queue is created this variable is not considered and changes must be made through the API calls.

Initial setting for algorithm to assign tasks to workers upon creating queue .

Change prior to calling work_queue_create, after queue is created this variable is not considered and changes must be made through the API calls.


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