Snakemake LSF profile

📢 NOTICE: We are seeking volunteers to maintain this repository as the current maintainers no longer use LSF. See this issue. 📢

Snakemake profile for running jobs on an LSF cluster.

Table of Contents

• Install
  • Dependencies
  • Profile
• Usage
  • Standard rule-specific cluster resource settings
  • Non-standard rule-specific cluster resource settings
• Known Issues
• Contributing

Install

Dependencies

This profile is deployed using Cookiecutter. If you do not have cookiecutter installed it can be easily installed using conda or pip by running:

pip install --user cookiecutter
# or
conda install -c conda-forge cookiecutter

If neither of these methods suits you, then visit the installation documentation for other options.

Profile

Download and set up the profile on your cluster

# create configuration directory that snakemake searches for profiles
profile_dir="${HOME}/.config/snakemake"
mkdir -p "$profile_dir"
# use cookiecutter to create the profile in the config directory
template="gh:Snakemake-Profiles/lsf"
cookiecutter --output-dir "$profile_dir" "$template"

You will then be prompted to set some default parameters.

LSF_UNIT_FOR_LIMITS

Default: KB
Valid options: KB, MB, GB, TB, PB, EB, ZB

⚠️IMPORTANT⚠️: This must be set to the same as LSF_UNIT_FOR_LIMITS on your cluster. This value is stored in your cluster's lsf.conf file. In general, this file is located at ${LSF_ENVDIR}/lsf.conf. So the easiest way to get this value is to run the following:

grep '^LSF_UNIT_FOR_LIMITS' ${LSF_ENVDIR}/lsf.conf

You should get something along the lines of LSF_UNIT_FOR_LIMITS=MB. If this command doesn't work, get in touch with your cluster administrator to find out the value.

As mentioned above, this is a very important parameter. It sets the scaling units to use for resource limits. So, if this value is MB on your cluster, then when setting the memory limit with -M 1000 the value is taken as megabytes. As snakemake allows you to set the memory for a rule with the resources: mem_mb parameter, it is important for this profile to know whether this then needs to be converted into other units when submitting jobs. See here for further information.

UNKWN_behaviour

Default: wait
Valid options: wait, kill

When LSF returns a job status of UNKWN do you want to wait for the host the job is running on to be contactable again - i.e. consider the job running - or kill it as outlined here?

ZOMBI_behaviour

Default: ignore
Valid options: ignore, kill

When LSF returns a job status of ZOMBI do you want to ignore this (not clean it up) or kill it as outlined here? Regardless of the option chosen, the job is considered failed.

latency_wait

Default: 5

This sets the default --latency-wait/--output-wait/-w parameter in snakemake.
From the snakemake --help menu

  --latency-wait SECONDS, --output-wait SECONDS, -w SECONDS
                        Wait given seconds if an output file of a job is not
                        present after the job finished. This helps if your
                        filesystem suffers from latency (default 5).

use_conda

Default: False
Valid options: False, True

This sets the default --use-conda parameter in snakemake.
From the snakemake --help menu

  --use-conda           If defined in the rule, run job in a conda
                        environment. If this flag is not set, the conda
                        directive is ignored.

use_singularity

Default: False
Valid options: False, True

This sets the default --use-singularity parameter in snakemake.
From the snakemake --help menu

  --use-singularity     If defined in the rule, run job within a singularity
                        container. If this flag is not set, the singularity
                        directive is ignored.

restart_times

Default: 0

This sets the default --restart-times parameter in snakemake.
From the snakemake --help menu

  --restart-times RESTART_TIMES
                        Number of times to restart failing jobs (defaults to
                        0).

print_shell_commands

Default: False
Valid options: False, True

This sets the default --printshellcmds/-p parameter in snakemake.
From the snakemake --help menu

  --printshellcmds, -p  Print out the shell commands that will be executed.

jobs

Default: 500

This sets the default --cores/--jobs/-j parameter in snakemake.
From the snakemake --help menu

  --cores [N], --jobs [N], -j [N]
                        Use at most N cores in parallel. If N is omitted or
                        'all', the limit is set to the number of available
                        cores.

In the context of a cluster, -j denotes the number of jobs submitted to the cluster at the same time¹.

default_mem_mb

Default: 1024

This sets the default memory, in megabytes, for a rule being submitted to the cluster without mem_mb set under resources.

See below for how to overwrite this in a rule.

default_cluster_logdir

Default: "logs/cluster"

This sets the directory under which cluster log files are written. The path is relative to the working directory of the pipeline. If it does not exist, it will be created.

The log files for a given rule are organised into sub-directories. This is to avoid having potentially thousands of files in one directory, as this can cause file system issues.
If you want to find the log files for a rule called foo, with wildcards sample=a,ext=fq then this would be located at logs/cluster/foo/sample=a,ext=fq/jobid<jobid>-<uuid>.out for the standard output and with extension .err for the standard error.
<jobid> is the internal jobid used by snakemake and is the same across multiple attempts at running the same rule.
<uuid> is a random 28-digit, separated by -, and is specific to each attempt at running a rule. So if a rule fails, and is restarted, the uuid will be different.

The reason for such a seemingly complex log-naming scheme is explained in Known Issues. However, you can override the name of the log files for a specific rule by following the instructions below.

default_queue

Default: None

The default queue on the cluster to submit jobs to. If left unset, then the default on your cluster will be used.
The bsub parameter that this controls is -q.

default_project

Default: None

The default project on the cluster to submit jobs with. If left unset, then the default on your cluster will be used.

The bsub parameter that this controls is -P.

max_status_checks_per_second

Default: 10

This sets the default --max-status-checks-per-second parameter in snakemake.
From the snakemake --help menu

  --max-status-checks-per-second MAX_STATUS_CHECKS_PER_SECOND
                        Maximal number of job status checks per second,
                        default is 10, fractions allowed.

max_jobs_per_second

Default: 10

This sets the default --max-jobs-per-second parameter in snakemake.
From the snakemake --help menu

  --max-jobs-per-second MAX_JOBS_PER_SECOND
                        Maximal number of cluster/drmaa jobs per second,
                        default is 10, fractions allowed.

max_status_checks

Default: 1

How many times to check the status of a job.

wait_between_tries

Default: 0.001

How many seconds to wait until checking the status of a job again (if max_status_checks is greater than 1).

profile_name

Default: lsf

The name to use for this profile. The directory for the profile is created as this name i.e. $HOME/.config/snakemake/<profile_name>.
This is also the value you pass to snakemake --profile <profile_name>.

Usage

Once set up is complete, this will allow you to run snakemake with the cluster profile using the --profile flag. For example, if the profile name was lsf, then you can run:

snakemake --profile lsf [snakemake options]

and pass any other valid snakemake options.

Standard rule-specific cluster resource settings

The following resources can be specified within a rule:

• threads: <INT> the number of threads needed for the job. If not specified, will default to the amount you set when initialising the profile.
• resources:
  • mem_mb = <INT>: the memory required for the rule, in megabytes. If not specified, will default to the amount you set when initialising the profile.
  • time_min: <INT>: the runtime limit required for the rule, in minutes.

NOTE: these settings will override the profile defaults.

Non-standard rule-specific cluster resource settings

Since the deprecation of cluster configuration files the ability to specify per-rule cluster settings is snakemake-profile-specific.

Per-rule configuration must be placed in a file called lsf.yaml and must be located in the working directory for the pipeline. If you set workdir manually within your workflow, the config file has to be in there.

NOTE: these settings are only valid for this profile and are not guaranteed to be valid on non-LSF cluster systems.

All settings are given with the rule name as the key, and the additional cluster settings as a string (scalar) or list (sequence).

Examples

Snakefile

rule foo:
    input: "foo.txt"
    output: "bar.txt"
    shell:
        "grep 'bar' {input} > {output}"

rule bar:
    input: "bar.txt"
    output: "file.out"
    shell:
        "echo blah > {output}"

lsf.yaml

__default__:
  - "-P project2"
  - "-W 1:05"

foo:
  - "-P gpu"
  - "-gpu 'gpu resources'"

In this example, we specify a default (__default__) project (-P) and runtime limit (-W) that will apply to all rules.
We then override the project and, additionally, specify GPU resources for the rule foo.

For those interested in the details, this will lead to a submission command, for foo that looks something like

$ bsub [options] -P project2 -W 1:05 -P gpu -gpu 'gpu resources' ...

Although -P is provided twice, LSF uses the last instance.

__default__: "-P project2 -W 1:05"

foo: "-P gpu -gpu 'gpu resources'"

The above is also a valid form of the previous example but not recommended.

Quote-escaping

Some LSF commands require multiple levels of quote-escaping.
For example, to exclude a node from job submission which has non-alphabetic characters in its name (docs): bsub -R "select[hname!='node-name']".

You can specify this in lsf.yaml as:

__default__:
    - "-R \"select[hname!='node-name']\""

Known Issues

If running very large snakemake pipelines, or there are many workflow management systems submitting and checking jobs at the same time on the same cluster, we have seen examples where retrieval of the job state from LSF returns an empty status. This causes problems as we do not know whether or not the job has passed/failed. In these circumstances, the status-checker will look at the log file for the job to see if it is complete or still running. Thus, the reason for the seemingly complex log file naming scheme. As the status-checker uses tail to get the status, if the standard output log file of the job is very large, then status checking will be slowed down as a result. If you run into these problems and the tail solution is no feasible, the first suggestion would be to reduce --max_status_checks_per_second and see if this helps.
Please raise an issue if you experience this, and the log file check doesn't seem to work.

Contributing

Please refer to CONTRIBUTING.md.