Yet another computing scheduler & cloud orchestration engine

Yascheduler is a simple job scheduler designed for submitting scientific calculations and copying back the results from the computing clouds.

Currently it supports several scientific simulation codes in chemistry and solid state physics. Any other scientific simulation code can be supported via the declarative control template system (see yascheduler.conf settings file). There is an example dummy C++ code with its configuration template.

Installation

Use pip and PyPI: pip install yascheduler.

By default, no cloud connectors are installed. To install the appropriate connector, use one of the commands:

• for Microsoft Azure: pip install yascheduler[azure]
• for Hetzner Cloud: pip install yascheduler[hetzner]
• for UpCloud: pip install yascheduler[upcloud]

The last updates and bugfixes can be obtained cloning the repository:

sh git clone https://github.com/tilde-lab/yascheduler.git pip install yascheduler/

The installation procedure creates the configuration file located at /etc/yascheduler/yascheduler.conf. The file contains credentials for Postgres database access, used directories, cloud providers and scientific simulation codes (called engines). Please check and amend this file with the correct credentials. The database and the system service should then be initialized with yainit script.

Usage

```python from yascheduler import Yascheduler

yac = Yascheduler() label = "test assignment" engine = "pcrystal" structinput = str(...) # simulation control file: crystal structure setupinput = str(...) # simulation control file: main setup, can include structinput result = yac.queuesubmittask( label, {"fort.34": structinput, "INPUT": setup_input}, engine ) print(result) ```

Or run directly in console with yascheduler (use a key -l DEBUG to change the log level).

Supervisor config reads e.g.:

[program:scheduler] command=/usr/local/bin/yascheduler user=root autostart=true autorestart=true stderr_logfile=/data/yascheduler.log stdout_logfile=/data/yascheduler.log

File paths can be set using the environment variables:

• YASCHEDULER_CONF_PATH

Configuration file.

Default: /etc/yascheduler/yascheduler.conf

• YASCHEDULER_LOG_PATH

Log file path.

Default: /var/log/yascheduler.log

• YASCHEDULER_PID_PATH

PID file.

Default: /var/run/yascheduler.pid

Configuration File Reference

Database Configuration [db]

Connection to a PostgreSQL database.

• user

The username to connect to the PostgreSQL server with.

• password

The user password to connect to the server with. This parameter is optional

• host

The hostname of the PostgreSQL server to connect with.

• port

The TCP/IP port of the PostgreSQL server instance.

Default: 5432

• database

The name of the database instance to connect with.

Default: Same as user

Local Settings [local]

• data_dir

Path to root directory of local data files. Can be relative to the current working directory.

Default: ./data (but it's always a good idea to set up explicitly!)

Example: /srv/yadata

• tasks_dir

Path to directory with tasks results.

Default: tasks under data_dir

Example: %(data_dir)s/tasks

• keys_dir

Path to directory with SSH keys. Make sure it only contains the private keys.

Default: keys under data_dir

Example: %(data_dir)s/keys

• engines_dir

Path to directory with engines repository.

Default: engines under data_dir

Example: %(data_dir)s/engines

• webhook_reqs_limit

Maximum number of in-flight webhook http requests.

Default: 5

• conn_machine_limit

Maximum number of concurrent SSH connection's connect requests.

Default: 10

• conn_machine_pending

Maximum number of pending SSH connection's connect requests.

Default: 10

• allocate_limit

Maximum number of concurrent task or node allocation requests.

Default: 20

• allocate_pending

Maximum number of pending task or node allocation requests.

Default: 1

• consume_limit

Maximum number of concurrent task's results downloads.

Default: 20

• consume_pending

Maximum number of pending task's results downloads.

Default: 1

• deallocate_limit

Maximum number of concurrent node deallocation requests.

Default: 5

• deallocate_pending

Maximum number of pending node deallocation requests.

Default: 1

Remote Settings [remote]

• data_dir

Path to root directory of data files on remote node. Can be relative to the remote current working directory (usually $HOME).

Default: ./data

Example: /src/yadata

• tasks_dir

Path to directory with tasks results on remote node.

Default: tasks under data_dir

Example: %(data_dir)s/tasks

• engines_dir

Path to directory with engines on remote node.

Default: engines under data_dir

Example: %(data_dir)s/engines

• user

Default ssh username.

Default: root

• jump_user

Username of default SSH jump host (if used).

• jump_host

Host of default SSH jump host (if used).

Providers [clouds]

All cloud providers settings are set in the [cloud] group. Each provider has its own settings prefix.

These settings are common to all the providers:

• *_max_nodes

The maximum number of nodes for a given provider. The provider is not used if the value is less than 1.

• *_user

Per provider override of remote.user.

• *_priority

Per provider priority of node allocation. Sorted in descending order, so the cloud with the highest value is the first.

• *_idle_tolerance

Per provider idle tolerance (in seconds) for deallocation of nodes.

Default: different for providers, starting from 120 seconds.

• *_jump_user

Username of this cloud SSH jump host (if used).

• *_jump_host

Host of this cloud SSH jump host (if used).

Hetzner

Settings prefix is hetzner.

• hetzner_token

API token with Read & Write permissions for the project.

• hetzner_server_type

Server type (size).

Default: cx52

• hetzner_location

Location name.

• hetzner_image_name

Image name for new nodes.

Default: debian-11

Azure

Azure Cloud should be pre-configured for yascheduler. See Cloud Providers.

Settings prefix is az.

• az_tenant_id

Tenant ID of Azure Active Directory.

• az_client_id

Application ID.

• az_client_secret

Client Secret value from the Application Registration.

• az_subscription_id

Subscription ID

• az_resource_group

Resource Group name.

Default: yascheduler-rg

• az_user

SSH username. root is not supported.

• az_location

Default location for resources.

Default: westeurope

• az_vnet

Virtual network name.

Default: yascheduler-vnet

• az_subnet

Subnet name.

Default: yascheduler-subnet

• az_nsg

Network security group name.

Default: yascheduler-nsg

• az_vm_image

OS image name.

Default: Debian

• az_vm_size

Machine size.

Default: Standard_B1s

UpCloud

Settings prefix is upcloud.

• upcloud_login

Username.

• upcloud_password

Password.

Engines [engine.*]

Supported engines should be defined in the section(s) [engine.name]. The name is alphanumeric string to represent the real engine name. Once set, it cannot be changed later.

• platforms

List of supported platform, separated by space or newline.

Default: debian-10 Example: mY-cOoL-OS another-cool-os

• platform_packages

A list of required packages, separated by space or newline, which will be installed by the system package manager.

Default: [] Example: openmpi-bin wget

• deploy_local_files

A list of filenames, separated by space or newline, which will be copied from local %(engines_dir)s/%(engine_name)s to remote %(engines_dir)s/%(engine_name)s. Conflicts with deploy_local_archive and deploy_remote_archive.

Example: dummyengine

• deploy_local_archive

A name of the local archive (.tar.gz) which will be copied from local %(engines_dir)s/%(engine_name)s to the remote machine and then unarchived to the %(engines_dir)s/%(engine_name)s. Conflicts with deploy_local_archive and deploy_remote_archive.

Example: dummyengine.tar.gz

• deploy_remote_archive

The url to the engine arhive (.tar.gz) which will be downloaded to the remote machine and then unarchived to the %(engines_dir)s/%(engine_name)s. Conflicts with deploy_local_archive and deploy_remote_archive.

Example: https://example.org/dummyengine.tar.gz

• spawn

This command is used by the scheduler to initiate calculations.

```sh cp {taskpath}/INPUT OUTPUT && mpirun -np {ncpus} --allow-run-as-root \ -wd {taskpath} {engine_path}/Pcrystal >> OUTPUT 2>&1

```

Example: {engine_path}/gulp < INPUT > OUTPUT

• check_pname

Process name used to check that the task is still running. Conflicts with check_cmd.

Example: dummyengine

• check_cmd

Command used to check that the task is still running. Conflicts with check_pname. See also check_cmd_code.

Example: ps ax -ocomm= | grep -q dummyengine

• check_cmd_code

Expected exit code of command from check_cmd. If code matches than task is running.

Default: 0

• sleep_interval

Interval in seconds between the task checks. Set to a higher value if you are expecting long running jobs.

Default: 10

• input_files

A list of task input file names, separated by a space or new line, that will be copied to the remote directory of the task before it is started. The first input is considered as the main input.

Example: INPUT sibling.file

• output_files

A list of task output file names, separated by a space or new line, that will be copied from the remote directory of the task after it is finished.

Example: INPUT OUTPUT

Aiida Integration

See the detailed instructions for the MPDS-AiiDA-CRYSTAL workflows as well as the ansible-mpds repository. In essence:

sh ssh aiidauser@localhost # important reentry scan verdi computer setup verdi computer test $COMPUTER verdi code setup

License