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LinuxConfigurator Operator
The LinuxConfigurator operator allows configuring systems tuned by Akamas by applying parameters related to the Linux kernel using different strategies.
The operator can configure provided Components or can configure every Component which has parameters related to the Linux kernel.
The parameters are applied via SSH protocol.
In the most basic use of the Operator, it is sufficient to add a task of type LinuxConfigurator in the workflow.
- name: LinuxConf
operator: LinuxConfigurator
arguments:
component: ComponentName
The operator makes use of properties specified in the component to identify which instance should be configured, how to access it, and any other information required to apply the configuration.
Name | Type | Value restrictions | Required | Default | Description |
component | String | It should match the name of an existing Component of the System under test | No | | The name of the Component for which available Linux kernel parameters will be configured |
If no
component
is provided, this operator will try to configure every parameter defined for the Components of the System under testThe following table highlights the properties that can be specified on components and are used by this operator.
Name | Type | Value restrictions | Required | Default | Description |
hostname | String | It should be a valid SSH host address | Yes | | SSH host address |
sshPort | Integer | 1≤ sshPort ≤65532 | Yes | 22 | SSH port |
username | String | | Yes | | SSH login username |
key | Multiline string | | Either key or password is required | | SSH login key, provided directly its value or the path of the file to import from. The operator supports RSA and DSA Keys |
password | String | | Either key or password is required | | |
blockDevices | List of objects | No | | Allows the user to restrict and specify to which block-device apply block-device-related parameters | |
networkDevices | List of objects | No | | Allows the user to restrict and specify to which network-device apply network-device-related parameters |
The properties
blockDevices
and networkDevices
allow specifying which parameters to apply to each block/network-device associated with the Component, as well as which block/network-device should be left untouched by the LinuxConfigurator.If the properties are omitted, then all block/network-devices associated with the Component will be configured will all the available related parameters.
All block-devices called loopN (where N is an integer number greater or equal to 0) are automatically excluded from the Component’s block-devices
The properties
blockDevices
and networkDevices
are lists of objects with the following structure:Name | Type | Value restrictions | Required | Default | Description |
name | String | It should be a valid regular expression to match block/network-devices | Yes | | A regular expression that matches block/network-devices to configure with related parameters of the Component |
parameters | List of strings | It should contain the names of matching parameters of the Component | No | | The list of parameters to be configured for the specified block/network-devices. If the list is empty, then no parameter will be applied for the block/network-devices matched by name |
blockDevices:
- name: "xvd[a-z]"
parameters:
- os_StorageReadAhead
- os_StorageQueueScheduler
In this example, only the parameters os_StorageReadAhead and os_StorageQeueuScheduler are applied to all the devices that match the regex "xvd[a-z]" (i.e. xvda, xvdb, …, xvdc).
blockDevices:
- name: "xvdb|loop0"
parameters:
- os_StorageMaxSectorsKb
In these examples, only the parameter os_StorageMaxSectorKb is applied to block device xvdb and loop0.
Note that the parameter is applied also to the block device loop0, since it is specified in the name filter, this overrides the default behavior since loopN devices are excluded by the Linux Optimization Pack
networkDevices:
- name: wlp4s0
parameters: []
In this example, no parameters are applied to the wlp4s0 network device, which is therefore excluded from the optimization.
To support the scenario in which some configuration parameters related to the Linux kernel may be applied using the strategies supported by this operator, while others with other strategies (e.g, using a file to be written on a remote machine), it is necessary to specify which parameters should be applied with the LinuxConfigurator, and this is done at the ComponentType level; moreover, still at the ComponentType level, it is necessary to specify which strategy should be used to configure each parameter. This information is already embedded in the Linux Optimization pack and, usually, no customization is required.
With this strategy, a parameter is configured by leveraging the sysctl utility. The sysctl variable to map to the parameter that needs to be configured is specified using the
key
argument.name: Component Type 1
description: My Component type
parameters:
- name: net_forwarding
domain:
type: integer
domain: [0, 1]
defaultValue: 1
operators:
# the parameter is configured using LinuxConfigurator
LinuxConfigurator:
sysctl:
key: net.ipv4.forwarding
With this strategy, a parameter is configured by echoing and piping its value into a provided file. The path of the file is specified using the
file
argument.name: Component Type 1
description: My Component type
parameters:
- name: os_MemoryTransparentHugepageEnabled
domain:
type: categorical
categories: [always, never]
defaultValue: always
operators:
LinuxConfigurator:
echo:
file: /sys/kernel/mm/transparent_hugepage/enabled
With this strategy, each possible value of a parameter is mapped to a command to be executed on the machine the LinuxConfigurator operates on(this is especially useful for categorical parameters).
name: Component Type 1
description: My Component type
parameters:
- name: os_MemorySwap
domain:
type: categorical
categories: [swapon, swapoff]
defaultValue: swapon
operators:
LinuxConfigurator:
map:
swapon: command1
swapoff: command2
With this strategy, a parameter is configured by executing a command into which the parameter value is interpolated.
name: Component Type 1
description: My Component type
parameters:
- name: os_MemorySwap
domain:
type: categorical
categories: [swapon, swapoff]
defaultValue: swapon
operators:
LinuxConfigurator:
command:
cmd: sudo ${value} -a
Last modified 4mo ago