Kernel Management¶

Here are the API calls to create and manage compute sessions.

Creating Kernel Session¶

URI: /kernel (/kernel/create also works for legacy)
Method: POST

Creates a kernel session if there is no existing (running) kernel with the same clientSessionToken. If there is an existing session and it has the same lang, no new session is created but the API returns successfully. In this case, config options are ignored and the created field in the response is set false (otherwise it’s true). If there is an existing session but with a different lang, then the API server returns an error.

Parameters¶

Parameter	Type	Description
`lang`	`str`	The kernel runtime type, usually in the form of the language name and its version tag connected with a colon. (e.g., `"python:latest"`)
`tag`	`str`	An optional per-session, user-provided tag for administrators to keep track of additional information of each session, such as which sessions are from which users.
`clientSessionToken`	`str`	Client-provided session token which can contain ASCII alphabets, numbers, and hyphens in the middle. The length must be between 4 to 64 characters inclusively. It is useful for aliasing the session with a human-friendly name. There can exist only one running session with the same token at a time, but you can reuse the same token if previous session has been terminated.
`config`	`object`	An optional Creation Config Object to specify extra kernel configuration.

Example:

{
  "lang": "python:3.6",
  "tag": "example-tag",
  "clientSessionToken": "EXAMPLE:STRING",
  "config": {
    "clusterSize": 1,
    "instanceMemory": 51240,
    "environ": {
      "MYCONFIG": "XXX",
    },
    "mounts": [
      "mydata",
      "mypkgs:.local/lib/python3.6/site-packages"
    ],
  }
}

Response¶

HTTP Status Code	Description
201 Created	The kernel is successfully created.
406 Not acceptable	The requested resource limits exceed the server’s own limits.

Fields	Type	Values
`kernelId`	`slug`	The kernel ID used for later API calls.
`created`	`bool`	True if the kernel is freshly created.

Example:

{
  "kernelId": "TSSJT2Z4SnmQhxjWMnJljg",
  "created": true
}

Getting Kernel Information¶

URI: /kernel/:id
Method: GET

Retrieves information about a kernel session. For performance reasons, the returned information may not be real-time; usually they are updated every a few seconds in the server-side.

Parameters¶

Parameter	Type	Description
`:id`	`slug`	The kernel ID.

Response¶

HTTP Status Code	Description
200 OK	The information is successfully returned.
404 Not Found	There is no such kernel.

Key	Type	Description
`lang`	`str`	The kernel’s programming language
`age`	`int` (msec)	The time elapsed since the kernel has started.
`memoryLimit`	`int` (KiB)	The memory limit of the kernel in KiB.
`numQueriesExecuted`	`int`	The number of times the kernel has been accessed.
`cpuCreditUsed`	`int` (msec)	The total time the kernel was running.

Destroying Kernel Session¶

URI: /kernel/:id
Method: DELETE

Terminates a kernel session.

Parameters¶

Parameter	Type	Description
`:id`	`slug`	The kernel ID.

Response¶

HTTP Status Code	Description
204 No Content	The kernel is successfully destroyed.
404 Not Found	There is no such kernel.

Key	Type	Description
`stats`	`object`	The Container Stats Object of the kernel when deleted.

Restarting Kernel Session¶

URI: /kernel/:id
Method: PATCH

Restarts a kernel session. The idle time of the kernel will be reset, but other properties such as the age and CPU credit will continue to accumulate. All global states such as global variables and modules imports are also reset.

Parameters¶

Parameter	Type	Description
`:id`	`slug`	The kernel ID.

Response¶

HTTP Status Code	Description
204 No Content	The kernel is successfully restarted.
404 Not Found	There is no such kernel.