openhpc
stackhpc.openhpc
This Ansible role installs packages and performs configuration to provide an OpenHPC v2.x Slurm cluster.
As a role it must be used from a playbook, for which a simple example is given below. This approach means it is totally modular with no assumptions about available networks or any cluster features except for some hostname conventions. Any desired cluster fileystem or other required functionality may be freely integrated using additional Ansible roles or other approaches.
The minimal image for nodes is a RockyLinux 8 GenericCloud image.
Role Variables
openhpc_extra_repos
: Optional list. Extra Yum repository definitions to configure, following the format of the Ansible
yum_repository module. Respected keys for
each list element:
name
: Requireddescription
: Optionalfile
: Requiredbaseurl
: Optionalmetalink
: Optionalmirrorlist
: Optionalgpgcheck
: Optionalgpgkey
: Optional
openhpc_slurm_service_enabled
: boolean, whether to enable the appropriate slurm service (slurmd/slurmctld).
openhpc_slurm_service_started
: Optional boolean. Whether to start slurm services. If set to false, all services will be stopped. Defaults to openhpc_slurm_service_enabled
.
openhpc_slurm_control_host
: Required string. Ansible inventory hostname (and short hostname) of the controller e.g. "{{ groups['cluster_control'] | first }}"
.
openhpc_slurm_control_host_address
: Optional string. IP address or name to use for the openhpc_slurm_control_host
, e.g. to use a different interface than is resolved from openhpc_slurm_control_host
.
openhpc_packages
: additional OpenHPC packages to install.
openhpc_enable
:
control
: whether to enable control hostdatabase
: whether to enable slurmdbdbatch
: whether to enable compute nodesruntime
: whether to enable OpenHPC runtime
openhpc_slurmdbd_host
: Optional. Where to deploy slurmdbd if are using this role to deploy slurmdbd, otherwise where an existing slurmdbd is running. This should be the name of a host in your inventory. Set this to none
to prevent the role from managing slurmdbd. Defaults to openhpc_slurm_control_host
.
openhpc_slurm_configless
: Optional, default false. If true then slurm's "configless" mode is used.
openhpc_munge_key
: Optional. Define a munge key to use. If not provided then one is generated but the openhpc_slurm_control_host
must be in the play.
openhpc_login_only_nodes
: Optional. If using "configless" mode specify the name of an ansible group containing nodes which are login-only nodes (i.e. not also control nodes), if required. These nodes will run slurmd
to contact the control node for config.
openhpc_module_system_install
: Optional, default true. Whether or not to install an environment module system. If true, lmod will be installed. If false, You can either supply your own module system or go without one.
slurm.conf
openhpc_slurm_partitions
: Optional. List of one or more slurm partitions, default []
. Each partition may contain the following values:
groups
: If there are multiple node groups that make up the partition, a list of group objects can be defined here. Otherwise,groups
can be omitted and the following attributes can be defined in the partition object:name
: The name of the nodes within this group.cluster_name
: Optional. An override for the top-level definitionopenhpc_cluster_name
.extra_nodes
: Optional. A list of additional node definitions, e.g. for nodes in this group/partition not controlled by this role. Each item should be a dict, with keys/values as per the "NODE CONFIGURATION" docs for slurm.conf. Note the keyNodeName
must be first.ram_mb
: Optional. The physical RAM available in each node of this group (slurm.conf parameterRealMemory
) in MiB. This is set using ansible facts if not defined, equivalent tofree --mebi
total *openhpc_ram_multiplier
.ram_multiplier
: Optional. An override for the top-level definitionopenhpc_ram_multiplier
. Has no effect ifram_mb
is set.gres
: Optional. List of dicts defining generic resources. Each dict must define:conf
: A string with the resource specification but requiring the format<name>:<type>:<number>
, e.g.gpu:A100:2
. Note thetype
is an arbitrary string.file
: A string with the File (path to device(s)) for this resource, e.g./dev/nvidia[0-1]
for the above example.
Note GresTypes must be set in
openhpc_config
if this is used.
default
: Optional. A boolean flag for whether this partion is the default. Valid settings areYES
andNO
.maxtime
: Optional. A partition-specific time limit following the format of slurm.conf parameterMaxTime
. The default value is given byopenhpc_job_maxtime
. The value should be quoted to avoid Ansible conversions.partition_params
: Optional. Mapping of additional parameters and values for partition configuration.
For each group (if used) or partition any nodes in an ansible inventory group <cluster_name>_<group_name>
will be added to the group/partition. Note that:
- Nodes may have arbitrary hostnames but these should be lowercase to avoid a mismatch between inventory and actual hostname.
- Nodes in a group are assumed to be homogenous in terms of processor and memory.
- An inventory group may be empty or missing, but if it is not then the play must contain at least one node from it (used to set processor information).
- Nodes may not appear in more than one group.
openhpc_job_maxtime
: Maximum job time limit, default '60-0'
(60 days). See slurm.conf parameter MaxTime
for format. The default is 60 days. The value should be quoted to avoid Ansible conversions.
openhpc_cluster_name
: name of the cluster.
openhpc_config
: Optional. Mapping of additional parameters and values for slurm.conf
. Note these will override any included in templates/slurm.conf.j2
.
openhpc_ram_multiplier
: Optional, default 0.95
. Multiplier used in the calculation: total_memory * openhpc_ram_multiplier
when setting RealMemory
for the partition in slurm.conf. Can be overriden on a per partition basis using openhpc_slurm_partitions.ram_multiplier
. Has no effect if openhpc_slurm_partitions.ram_mb
is set.
openhpc_state_save_location
: Optional. Absolute path for Slurm controller state (slurm.conf
parameter StateSaveLocation)
Accounting
By default, no accounting storage is configured. OpenHPC v1.x and un-updated OpenHPC v2.0 clusters support file-based accounting storage which can be selected by setting the role variable openhpc_slurm_accounting_storage_type
to accounting_storage/filetxt
1. Accounting for OpenHPC v2.1 and updated OpenHPC v2.0 clusters requires the Slurm database daemon, slurmdbd
(although job completion may be a limited alternative, see below. To enable accounting:
- Configure a mariadb or mysql server as described in the slurm accounting documentation on one of the nodes in your inventory and set
openhpc_enable.database
totrue
for this node. - Set
openhpc_slurm_accounting_storage_type
toaccounting_storage/slurmdbd
. - Configure the variables for
slurmdbd.conf
below.
The role will take care of configuring the following variables for you:
openhpc_slurm_accounting_storage_host
: Where the accounting storage service is running i.e where slurmdbd running.
openhpc_slurm_accounting_storage_port
: Which port to use to connect to the accounting storage.
openhpc_slurm_accounting_storage_user
: Username for authenticating with the accounting storage.
openhpc_slurm_accounting_storage_pass
: Mungekey or database password to use for authenticating.
For more advanced customisation or to configure another storage type, you might want to modify these values manually.
Job accounting
This is largely redundant if you are using the accounting plugin above, but will give you basic accounting data such as start and end times. By default no job accounting is configured.
openhpc_slurm_job_comp_type
: Logging mechanism for job accounting. Can be one of
jobcomp/filetxt
, jobcomp/none
, jobcomp/elasticsearch
.
openhpc_slurm_job_acct_gather_type
: Mechanism for collecting job accounting data. Can be one
of jobacct_gather/linux
, jobacct_gather/cgroup
and jobacct_gather/none
.
openhpc_slurm_job_acct_gather_frequency
: Sampling period for job accounting (seconds).
openhpc_slurm_job_comp_loc
: Location to store the job accounting records. Depends on value of
openhpc_slurm_job_comp_type
, e.g for jobcomp/filetxt
represents a path on disk.
slurmdbd.conf
The following options affect slurmdbd.conf
. Please see the slurm documentation for more details.
You will need to configure these variables if you have set openhpc_enable.database
to true
.
openhpc_slurmdbd_port
: Port for slurmdb to listen on, defaults to 6819
.
openhpc_slurmdbd_mysql_host
: Hostname or IP Where mariadb is running, defaults to openhpc_slurm_control_host
.
openhpc_slurmdbd_mysql_database
: Database to use for accounting, defaults to slurm_acct_db
.
openhpc_slurmdbd_mysql_password
: Password for authenticating with the database. You must set this variable.
openhpc_slurmdbd_mysql_username
: Username for authenticating with the database, defaults to slurm
.
Example Inventory
And an Ansible inventory as this:
[openhpc_login]
openhpc-login-0 ansible_host=10.60.253.40 ansible_user=centos
[openhpc_compute]
openhpc-compute-0 ansible_host=10.60.253.31 ansible_user=centos
openhpc-compute-1 ansible_host=10.60.253.32 ansible_user=centos
[cluster_login:children]
openhpc_login
[cluster_control:children]
openhpc_login
[cluster_batch:children]
openhpc_compute
Example Playbooks
To deploy, create a playbook which looks like this:
---
- hosts:
- cluster_login
- cluster_control
- cluster_batch
become: yes
roles:
- role: openhpc
openhpc_enable:
control: "{{ inventory_hostname in groups['cluster_control'] }}"
batch: "{{ inventory_hostname in groups['cluster_batch'] }}"
runtime: true
openhpc_slurm_service_enabled: true
openhpc_slurm_control_host: "{{ groups['cluster_control'] | first }}"
openhpc_slurm_partitions:
- name: "compute"
openhpc_cluster_name: openhpc
openhpc_packages: []
...
1 Slurm 20.11 removed accounting_storage/filetxt
as an option. This version of Slurm was introduced in OpenHPC v2.1 but the OpenHPC repos are common to all OpenHPC v2.x releases. ↩
This role provisions an exisiting cluster to support OpenHPC control and batch compute functions and installs necessary runtime packages.
ansible-galaxy install stackhpc/ansible-role-openhpc