CDN 2.4¶

Overview¶

CDN 2.4 implements the following features in addition to CDN 2.1, 2.2 and 2.3:

CDN signaling connections monitoring
CDN signaling connections management

CDN signaling connections monitoring¶

CDN 2.4 allows to check current state of signaling connections with other CDN nodes using REST API or CLI. Thus, CDN coherence can be monitored from backend.

Using REST API¶

REST API query /cdn/show_nodes returns current state and statistics of signaling connection with other CDN nodes

[
  {
    "version": "2.3",
    "role": "TRANSCODER",
    "inboundConnected": true,
    "outboundConnected": false,
    "globalState": "ACTIVE",
    "processingState": "NEW_STREAMS_ALLOWED",
    "id": "192.168.1.64"
  },
  {
    "version": "2.4",
    "role": "EDGE",
    "inboundConnected": true,
    "outboundConnected": false,
    "globalState": "ACTIVE",
    "processingState": "NEW_STREAMS_ALLOWED",
    "connectionStats": {
      "lastRtt": 2,
      "lastSn": 24,
      "lastMessageSentMs": 1592359761801,
      "lastACKReceivedMs": 1592359761802,
      "maxRtt": 1224,
      "inFlightSize": 0
    },
    "id": "192.168.1.65"
  }
]

Parameters¶

Parameter	Description	Example
inboundConnected	Inbound connection is established from this node	`true`
outboundConnected	Outbound connection is established to this node	`false`
lastRtt	Last packet RTT, ms	`2`
lastSn	Last packet sequence number	`24`
lastMessageSentMs	Last message sent timestamp, ms	`1592359761801`
lastACKReceivedMs	Last acknowlegement received timestamp, ms	`1592359761802`
maxRtt	Maximum RTT, ms	`1224`
inFlightSize	Current sending packet size, bytes	`0`

Note that statistics is not available for previous CDN versions nodes, connection status only can be checked.

Using CLI¶

CLI v 2 command

cdn show-connections

shows CDN signaling connections statistics (for CDN 2.4 nodes only)

Ip            State  Inbound Outbound Last rtt Max rtt Last SN In flight
-------------------------------------------------------------------------
192.168.1.39  ACTIVE false   true     1        2057    127     0

CDN signaling connections management¶

In some cases, certain CDN node coherence may be broken, for example, due to network issues between nodes. To restore the CDN coherence, singnaling connections reset and re-establishing may require. In previous CDN versions, this can be done by node restart only. In CDN 2.4, signaling connections can be reset using REST API. This operation does not affect media streams which already passing through this node.

Connection reset using REST API¶

REST query should be HTTP/HTTPS POST request as follows:

HTTP: http://test.flashphoner.com:8081/rest-api/cdn/connection/reset_outbound
HTTPS: https://test.flashphoner.com:8444/rest-api/cdn/connection/reset_outbound

Where:

test.flashphoner.com - WCS server address
8081 - REST / HTTP port
8444 - HTTPS port
rest-api - mandatory URL part
/cdn/connection/reset_outbound - REST method used

REST queries should be sent to the node on which connections must be reset

/cdn/connection/reset_inbound¶

Reset inbound connection from this node

Request example¶

POST /rest-api/cdn/connection/reset_inbound HTTP/1.1
Host: localhost:8081
Content-Type: application/json

{
    "nodeId":"192.168.1.65"
}

Response example¶

HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json

Return codes¶

Code	Reason
200	OK
404	Not found

/cdn/connection/reset_outbound¶

Reset outbound connection to this node

Request example¶

POST /rest-api/cdn/connection/reset_outbound HTTP/1.1
Host: localhost:8081
Content-Type: application/json

{
    "nodeId":"192.168.1.65"
}

Response example¶

HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json

Return codes¶

Code	Reason
200	OK
404	Not found

/cdn/connection/reset_all¶

Reset all CDN connections on this node (since build 5.2.1222)

Request example¶

POST /rest-api/cdn/connection/reset_all HTTP/1.1
Host: localhost:8081
Content-Type: application/json

Response example¶

HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json

Return codes¶

Code	Reason
200	OK

Parameters¶

Parameter	Description	Example
nodeId	Node id (IP address) to reset connection with	`192.168.1.65`

Signaling connections tuning¶

Inactive connections reset configuration¶

Signaling connection can be closed if server does not receive any packets during a certain timeout. The feature is enabled by the following parameters for incoming and outgoing signaling connections respectively

cdn_inbound_ws_read_socket_timeout=true
cdn_outbound_ws_read_socket_timeout=true

By default, the read timeout is set to 60 seconds

cdn_inbound_ws_read_socket_timeout_sec=60
cdn_outbound_ws_read_socket_timeout_sec=60

Backward compatibility with CDN 2.0-2.3¶

Statistics is not displayed for connections with previous CDN versions nodes
Connection with previous CDN version node can be reset