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MaxScale 24.02 Session Resource

Session Resource

A session is an abstraction of a client connection, any number of related backend connections, a router module session and possibly filter module sessions. Each session is created on a service and each service can have multiple sessions.

Resource Operations

Get a session

GET /v1/sessions/:id

Get a single session. :id must be a valid session ID. The session ID is the same that is exposed to the client as the connection ID.

This endpoint also supports the rdns=true parameter, which instructs MaxScale to perform reverse DNS on the client IP address. As this requires communicating with an external server, the operation may be expensive.

Response

Status: 200 OK

{
    "data": {
        "attributes": {
            "client": {
                "cipher": "",
                "connection_attributes": {
                    "_client_name": "libmariadb",
                    "_client_version": "3.3.4",
                    "_os": "Linux",
                    "_pid": "502300",
                    "_platform": "x86_64",
                    "_server_host": "127.0.0.1"
                },
                "sescmd_history_len": 1,
                "sescmd_history_stored_metadata": 0,
                "sescmd_history_stored_responses": 1
            },
            "connected": "Fri, 05 Jan 2024 07:24:06 GMT",
            "connections": [
                {
                    "cipher": "",
                    "connection_id": 129,
                    "server": "server1"
                }
            ],
            "idle": 5.2000000000000002,
            "io_activity": 16,
            "log": [],
            "memory": {
                "connection_buffers": {
                    "backends": {
                        "server1": {
                            "misc": 662,
                            "readq": 0,
                            "total": 662,
                            "writeq": 0
                        }
                    },
                    "client": {
                        "misc": 654,
                        "readq": 65536,
                        "total": 66190,
                        "writeq": 0
                    },
                    "total": 66852
                },
                "exec_metadata": 0,
                "last_queries": 0,
                "sescmd_history": 485,
                "total": 67337,
                "variables": 0
            },
            "parameters": {
                "log_debug": false,
                "log_error": false,
                "log_info": false,
                "log_notice": false,
                "log_warning": false
            },
            "port": 40664,
            "queries": [],
            "remote": "127.0.0.1",
            "seconds_alive": 5.209291554,
            "state": "Session started",
            "thread": 2,
            "user": "maxuser"
        },
        "id": "1",
        "links": {
            "self": "http://localhost:8989/v1/sessions/1/"
        },
        "relationships": {
            "services": {
                "data": [
                    {
                        "id": "RW-Split-Router",
                        "type": "services"
                    }
                ],
                "links": {
                    "related": "http://localhost:8989/v1/services/",
                    "self": "http://localhost:8989/v1/sessions/1/relationships/services/"
                }
            }
        },
        "type": "sessions"
    },
    "links": {
        "self": "http://localhost:8989/v1/sessions/1/"
    }
}

Get all sessions

GET /v1/sessions

Get all sessions.

Response

Status: 200 OK

{
    "data": [
        {
            "attributes": {
                "client": {
                    "cipher": "",
                    "connection_attributes": {
                        "_client_name": "libmariadb",
                        "_client_version": "3.3.4",
                        "_os": "Linux",
                        "_pid": "502300",
                        "_platform": "x86_64",
                        "_server_host": "127.0.0.1"
                    },
                    "sescmd_history_len": 1,
                    "sescmd_history_stored_metadata": 0,
                    "sescmd_history_stored_responses": 1
                },
                "connected": "Fri, 05 Jan 2024 07:24:06 GMT",
                "connections": [
                    {
                        "cipher": "",
                        "connection_id": 129,
                        "server": "server1"
                    }
                ],
                "idle": 5.2000000000000002,
                "io_activity": 16,
                "log": [],
                "memory": {
                    "connection_buffers": {
                        "backends": {
                            "server1": {
                                "misc": 662,
                                "readq": 0,
                                "total": 662,
                                "writeq": 0
                            }
                        },
                        "client": {
                            "misc": 654,
                            "readq": 65536,
                            "total": 66190,
                            "writeq": 0
                        },
                        "total": 66852
                    },
                    "exec_metadata": 0,
                    "last_queries": 0,
                    "sescmd_history": 485,
                    "total": 67337,
                    "variables": 0
                },
                "parameters": {
                    "log_debug": false,
                    "log_error": false,
                    "log_info": false,
                    "log_notice": false,
                    "log_warning": false
                },
                "port": 40664,
                "queries": [],
                "remote": "127.0.0.1",
                "seconds_alive": 5.2105843680000001,
                "state": "Session started",
                "thread": 2,
                "user": "maxuser"
            },
            "id": "1",
            "links": {
                "self": "http://localhost:8989/v1/sessions/1/"
            },
            "relationships": {
                "services": {
                    "data": [
                        {
                            "id": "RW-Split-Router",
                            "type": "services"
                        }
                    ],
                    "links": {
                        "related": "http://localhost:8989/v1/services/",
                        "self": "http://localhost:8989/v1/sessions/1/relationships/services/"
                    }
                }
            },
            "type": "sessions"
        }
    ],
    "links": {
        "self": "http://localhost:8989/v1/sessions/"
    }
}

Update a Session

PATCH /v1/sessions/:id

The request body must be a JSON object which represents the new configuration of the session. The :id must be a valid session ID that is active.

The log_debug, log_info, log_notice, log_warning and log_error boolean parameters control whether the associated logging level is enabled:

{
    "data": {
        "attributes": {
            "parameters": {
                "log_info": true
            }
        }
    }
}

The filters that a session uses can be updated by re-defining the filter relationship of the session. This causes new filter sessions to be opened immediately. The old filter session are closed and replaced with the new filter session the next time the session is idle. The order in which the filters are defined in the request body is the order in which the filters are installed, similar to how the filter relationship for services behaves.

{
    "data": {
        "attributes": {
            "relationships": {
                "filters": {
                    "data": [
                        { "id": "my-cache-filter" },
                        { "id": "my-log-filter" }
                    ]
                }
            }
        }
    }
}

Response

Session is modified:

Status: 204 No Content

Restart a Session

POST /v1/sessions/:id/restart

This endpoint causes the session to re-read the configuration from the service. As a result of this, all backend connections will be closed and then opened again. All router and filter sessions will be created again which means that for modules that perform something whenever a new module session is opened, this behaves as if a new session was started.

This endpoint can be used to apply configuration changes that were done after the session was started. This can be useful for situations where the client connections live for a long time and connections are not recycled often enough.

Response

Session is was restarted:

Status: 204 No Content

Restart all Sessions

POST /v1/sessions/restart

This endpoint does the same thing as the /v1/sessions/:id/restart endpoint except that it applies to all sessions.

Response

Session is was restarted:

Status: 204 No Content

Kill a Session

DELETE /v1/sessions/:id

This endpoint causes the session to be forcefully closed.

Request Parameters

This endpoint supports the following request parameters.

  • ttl

  • The time after which the session is killed. If this parameter is not given, the session is killed immediately. This can be used to give the session time to finish the work it is performing before the connection is closed.

Response

Session was killed:

Status: 204 No Content

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