feat: Adding --cluster-cancel and --cluster-cancel-nargs

docs/executing/cluster.rst

@@ -48,8 +48,7 @@ and forward it to the cluster scheduler:
 
 In order to avoid specifying ``runtime_min`` for each rule, you can make use of the ``--default-resources`` flag, see ``snakemake --help``.
 
-If your cluster system supports `DRMAA <https://www.drmaa.org/>`_, Snakemake can make use of that to increase the control over jobs.
-E.g. jobs can be cancelled upon pressing ``Ctrl+C``, which is not possible with the generic ``--cluster`` support.
+If your cluster system supports `DRMAA <https://www.drmaa.org/>`_, Snakemake can make use of that to control jobs.
 With DRMAA, no ``qsub`` command needs to be provided, but system specific arguments can still be given as a string, e.g.
 
 .. code-block:: console
@@ -61,6 +60,13 @@ Else, the arguments will be interpreted as part of the normal Snakemake argument
 
 Adapting to a specific cluster can involve quite a lot of options. It is therefore a good idea to setup a :ref:`a profile <profiles>`.
 
+.. note::
+    Are you using the SLURM job scheduler?
+
+    In this case, it will be more robust to use the ``--cluster``, ``--cluster-status``, and ``--cluster-cancel`` arguments than using DRMAA.
+    The reason is that the slurm-drmaa package is not maintained by the SLURM vendor SchedMD and less well supported.
+    Effectively, you will run into timeouts in DRMAA calls sooner.
+
 --------------
 Job Properties
 --------------

docs/tutorial/additional_features.rst

@@ -272,6 +272,13 @@ To use this script call snakemake similar to below, where ``status.py`` is the s
     $ snakemake all --jobs 100 --cluster "sbatch --cpus-per-task=1 --parsable" --cluster-status ./status.py
 
 
+Using --cluster-cancel
+::::::::::::::::::::::
+
+When snakemake is terminated by pressing ``Ctrl-C``, it will cancel all currently running node when using ``--drmaa``.
+You can get the same behaviour with ``--cluster`` by adding ``--cluster-cancel`` and passing a command to use for canceling jobs by their jobid (e.g., ``scancel`` for SLURM or ``qdel`` for SGE).
+Most job schedulers can be passed multiple jobids and you can use ``--cluster-cancel-nargs`` to limit the number of arguments (default is 1000 which is reasonable for most schedulers).
+
 Constraining wildcards
 ::::::::::::::::::::::
 

snakemake/__init__.py

@@ -166,6 +166,8 @@ def snakemake(
     tibanna_config=False,
     assume_shared_fs=True,
     cluster_status=None,
+    cluster_cancel=None,
+    cluster_cancel_nargs=None,
     export_cwl=None,
     show_failed_logs=False,
     keep_incomplete=False,
@@ -296,6 +298,8 @@ def snakemake(
         tibanna_config (list):      Additional tibanna config e.g. --tibanna-config spot_instance=true subnet=<subnet_id> security group=<security_group_id>
         assume_shared_fs (bool):    assume that cluster nodes share a common filesystem (default true).
         cluster_status (str):       status command for cluster execution. If None, Snakemake will rely on flag files. Otherwise, it expects the command to return "success", "failure" or "running" when executing with a cluster jobid as a single argument.
+        cluster_cancel (str):       command to cancel multiple job IDs (like SLURM 'scancel') (default None)
+        cluster_cancel_nargs (int): maximal number of job ids to pass to cluster_cancel (default 1000)
         export_cwl (str):           Compile workflow to CWL and save to given file
         log_handler (function):     redirect snakemake output to this custom log handler, a function that takes a log message dictionary (see below) as its only argument (default None). The log message dictionary for the log handler has to following entries:
         keep_incomplete (bool):     keep incomplete output files of failed jobs
@@ -691,6 +695,8 @@ def snakemake(
                     tibanna_config=tibanna_config,
                     assume_shared_fs=assume_shared_fs,
                     cluster_status=cluster_status,
+                    cluster_cancel=cluster_cancel,
+                    cluster_cancel_nargs=cluster_cancel_nargs,
                     max_jobs_per_second=max_jobs_per_second,
                     max_status_checks_per_second=max_status_checks_per_second,
                     overwrite_groups=overwrite_groups,
@@ -777,6 +783,8 @@ def snakemake(
                     conda_create_envs_only=conda_create_envs_only,
                     assume_shared_fs=assume_shared_fs,
                     cluster_status=cluster_status,
+                    cluster_cancel=cluster_cancel,
+                    cluster_cancel_nargs=cluster_cancel_nargs,
                     report=report,
                     report_stylesheet=report_stylesheet,
                     export_cwl=export_cwl,
@@ -2131,6 +2139,19 @@ def get_argument_parser(profile=None):
         "'success' if the job was successfull, 'failed' if the job failed and "
         "'running' if the job still runs.",
     )
+    group_cluster.add_argument(
+        "--cluster-cancel",
+        default=None,
+        help="Specify a command that allows to stop currently running jobs. "
+        "The command will be passed a single argument, the job id.",
+    )
+    group_cluster.add_argument(
+        "--cluster-cancel-nargs",
+        type=int,
+        default=1000,
+        help="Specify maximal number of job ids to pass to --cluster-cancel "
+        "command, defaults to 1000.",
+    )
     group_cluster.add_argument(
         "--drmaa-log-dir",
         metavar="DIR",
@@ -2403,8 +2424,9 @@ def adjust_path(f):
                 args.cluster_config = adjust_path(args.cluster_config)
         if args.cluster_sync:
             args.cluster_sync = adjust_path(args.cluster_sync)
-        if args.cluster_status:
-            args.cluster_status = adjust_path(args.cluster_status)
+        for key in "cluster_status", "cluster_cancel":
+            if getattr(args, key):
+                setattr(args, key, adjust_path(getattr(args, key)))
         if args.report_stylesheet:
             args.report_stylesheet = adjust_path(args.report_stylesheet)
 
@@ -2876,6 +2898,8 @@ def open_browser():
             default_remote_prefix=args.default_remote_prefix,
             assume_shared_fs=not args.no_shared_fs,
             cluster_status=args.cluster_status,
+            cluster_cancel=args.cluster_cancel,
+            cluster_cancel_nargs=args.cluster_cancel_nargs,
             export_cwl=args.export_cwl,
             show_failed_logs=args.show_failed_logs,
             keep_incomplete=args.keep_incomplete,

snakemake/executors/__init__.py

@@ -108,7 +108,7 @@ def get_set_resources_args(self):
                     "{}:{}={}".format(rule, name, value)
                     for rule, res in self.workflow.overwrite_resources.items()
                     for name, value in res.items()
-                ),
+                )
             )
         return ""
 
@@ -923,6 +923,8 @@ def __init__(
         cores,
         submitcmd="qsub",
         statuscmd=None,
+        cancelcmd=None,
+        cancelnargs=None,
         cluster_config=None,
         jobname="snakejob.{rulename}.{jobid}.sh",
         printreason=False,
@@ -944,7 +946,12 @@ def __init__(
             )
 
         self.statuscmd = statuscmd
+        self.cancelcmd = cancelcmd
+        self.cancelnargs = cancelnargs
         self.external_jobid = dict()
+        # We need to collect all external ids so we can properly cancel even if
+        # the status update queue is running.
+        self.all_ext_jobids = list()
 
         super().__init__(
             workflow,
@@ -976,8 +983,38 @@ def __init__(
             )
 
     def cancel(self):
-        logger.info("Will exit after finishing currently running jobs.")
-        self.shutdown()
+        def _chunks(lst, n):
+            """Yield successive n-sized chunks from lst."""
+            for i in range(0, len(lst), n):
+                yield lst[i : i + n]
+
+        if self.cancelcmd:  # We have --cluster-[m]cancel
+            # Enumerate job IDs and create chunks.  If cancelnargs evaluates to false (0/None)
+            # then pass all job ids at once
+            jobids = list(self.all_ext_jobids)
+            chunks = list(_chunks(jobids, self.cancelnargs or len(jobids)))
+            # Go through the chunks and cancel the jobs, warn in case of failures.
+            failures = 0
+            for chunk in chunks:
+                try:
+                    cancel_timeout = 2  # rather fail on timeout than miss canceling all
+                    subprocess.check_call(
+                        [self.cancelcmd] + chunk, shell=False, timeout=cancel_timeout
+                    )
+                except subprocess.SubprocessError:
+                    failures += 1
+            if failures:
+                logger.info(
+                    (
+                        "{} out of {} calls to --cluster-cancel failed.  This is safe to "
+                        "ignore in most cases."
+                    ).format(failures, len(chunks))
+                )
+        else:
+            logger.info(
+                "No --cluster-cancel given. Will exit after finishing currently running jobs."
+            )
+            self.shutdown()
 
     def register_job(self, job):
         # Do not register job here.
@@ -1008,6 +1045,7 @@ def run(self, job, callback=None, submit_callback=None, error_callback=None):
                 )
                 submit_callback(job)
                 with self.lock:
+                    self.all_ext_jobids.append(ext_jobid)
                     self.active_jobs.append(
                         GenericClusterJob(
                             job,
@@ -1063,6 +1101,7 @@ def run(self, job, callback=None, submit_callback=None, error_callback=None):
         submit_callback(job)
 
         with self.lock:
+            self.all_ext_jobids.append(ext_jobid)
             self.active_jobs.append(
                 GenericClusterJob(
                     job,

snakemake/scheduler.py

@@ -4,6 +4,7 @@
 __license__ = "MIT"
 
 import os, signal, sys
+import datetime
 import threading
 import operator
 import time
@@ -63,6 +64,8 @@ def __init__(
         cluster_status=None,
         cluster_config=None,
         cluster_sync=None,
+        cluster_cancel=None,
+        cluster_cancel_nargs=None,
         drmaa=None,
         drmaa_log_dir=None,
         kubernetes=None,
@@ -194,6 +197,8 @@ def __init__(
                     constructor = partial(
                         GenericClusterExecutor,
                         statuscmd=cluster_status,
+                        cancelcmd=cluster_cancel,
+                        cancelnargs=cluster_cancel_nargs,
                         max_status_checks_per_second=max_status_checks_per_second,
                     )
 
@@ -449,7 +454,7 @@ def schedule(self):
                 if user_kill or (not self.keepgoing and errors) or executor_error:
                     if user_kill == "graceful":
                         logger.info(
-                            "Will exit after finishing " "currently running jobs."
+                            "Will exit after finishing currently running jobs (scheduler)."
                         )
 
                     if executor_error:
@@ -581,10 +586,7 @@ def _free_resources(self, job):
                 value = self.calc_resource(name, value)
                 self.resources[name] += value
 
-    def _proceed(
-        self,
-        job,
-    ):
+    def _proceed(self, job):
         """Do stuff after job is finished."""
         with self._lock:
             self._tofinish.append(job)
@@ -653,10 +655,7 @@ def job_selector_ilp(self, jobs):
             # assert self.resources["_cores"] > 0
             scheduled_jobs = {
                 job: pulp.LpVariable(
-                    "job_{}".format(idx),
-                    lowBound=0,
-                    upBound=1,
-                    cat=pulp.LpInteger,
+                    "job_{}".format(idx), lowBound=0, upBound=1, cat=pulp.LpInteger
                 )
                 for idx, job in enumerate(jobs)
             }

snakemake/workflow.py

@@ -615,6 +615,8 @@ def execute(
         conda_create_envs_only=False,
         assume_shared_fs=True,
         cluster_status=None,
+        cluster_cancel=None,
+        cluster_cancel_nargs=None,
         report=None,
         report_stylesheet=None,
         export_cwl=False,
@@ -982,6 +984,8 @@ def files(items):
             touch=touch,
             cluster=cluster,
             cluster_status=cluster_status,
+            cluster_cancel=cluster_cancel,
+            cluster_cancel_nargs=cluster_cancel_nargs,
             cluster_config=cluster_config,
             cluster_sync=cluster_sync,
             jobname=jobname,

tests/common.py

@@ -4,8 +4,11 @@
 __license__ = "MIT"
 
 import os
+import signal
 import sys
+import shlex
 import shutil
+import time
 from os.path import join
 import tempfile
 import hashlib
@@ -98,6 +101,7 @@ def run(
     targets=None,
     container_image=os.environ.get("CONTAINER_IMAGE", "snakemake/snakemake:latest"),
     shellcmd=None,
+    sigint_after=None,
     **params,
 ):
     """
@@ -156,16 +160,24 @@ def run(
             raise ValueError("shellcmd does not start with snakemake")
         shellcmd = "{} -m {}".format(sys.executable, shellcmd)
         try:
-            subprocess.check_output(
-                shellcmd,
-                cwd=path if no_tmpdir else tmpdir,
-                shell=True,
-            )
-            success = True
+            if sigint_after is None:
+                subprocess.check_output(
+                    shellcmd, cwd=path if no_tmpdir else tmpdir, shell=True
+                )
+                success = True
+            else:
+                with subprocess.Popen(
+                    shlex.split(shellcmd), cwd=path if no_tmpdir else tmpdir
+                ) as process:
+                    time.sleep(sigint_after)
+                    process.send_signal(signal.SIGINT)
+                    time.sleep(2)
+                    success = process.returncode == 0
         except subprocess.CalledProcessError as e:
             success = False
             print(e.stderr, file=sys.stderr)
     else:
+        assert sigint_after is None, "Cannot sent SIGINT when calling directly"
         success = snakemake(
             snakefile=original_snakefile if no_tmpdir else snakefile,
             cores=cores,

tests/test_cluster_cancelscript/Snakefile.nonstandard

@@ -0,0 +1,13 @@
+from snakemake import shell
+
+
+rule all:
+	input: 'f.1', 'f.2'
+
+rule one:
+	output: 'f.1'
+	shell: "sleep 120s; touch {output}"
+
+rule two:
+	output: 'f.2'
+	shell: "sleep 120s; touch {output}"

tests/test_cluster_cancelscript/expected-results/scancel.txt

@@ -0,0 +1,2 @@
+cancel
+cancel

tests/test_cluster_cancelscript/sbatch

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -x
+echo --sbatch-- >> sbatch.log
+echo `date` >> sbatch.log
+tail -n1 $1 >> sbatch.log
+cat $1 >> sbatch.log
+# daemonize job script
+nohup sh $1 0<&- &>/dev/null &
+# print PID for job number
+echo $!

tests/test_cluster_cancelscript/scancel.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+set -x
+echo `date`
+echo cancel $* >>scancel.txt
+
+list_descendants ()
+{
+  local children=$(ps -o pid= --ppid "$1")
+
+  for pid in $children
+  do
+    list_descendants "$pid"
+  done
+
+  echo "$children"
+}
+
+for x in $*; do
+    kill $(list_descendants $x)
+done

tests/test_cluster_cancelscript/status.sh

@@ -0,0 +1 @@
+echo running

tests/test_cluster_cancelscript/test.in

@@ -0,0 +1 @@
+testz0r