Seachange Video Server System Overview

Seachange Video Server System Overview-[1]

Http://www.video.com.cn/tech/server/200804/1209001903779.html

Video.com.cn (video network) Source: China Digital TV

To meet the needs of increasing broadcast channels, expanding the broadcast scale, and promoting HD broadcast modes, the Hard Disk Broadcast System of conventional CCTV channels adopts seachange's video server system. This service
The cluster structure of the system is separated by the broadcast cluster and the upload cluster. The non-image dual-cluster is used for uploading, and the image dual-cluster is used for broadcasting. The codec uses the mediaclient client platform.
All video servers are in mxf format. After more than half a year of actual operation, the system basically met the requirements of CCTV.

I. Basic concepts of seachange Video Server

1. mediacluster

Mediacluster: A video server cluster is a network composed of multiple servers. Each video server is called a node. Generally, a node is a complete server.
The server works the same way. However, unlike other server systems, if a node fails. Mediacluster can continue to work while ensuring normal broadcast
Seachange can automatically restore lost data with no loss through its unique raid 2 technology.

2. raid2 Technology

Any node in mediacluster is connected to every other node in the network and forms a two-way star topology. This fully connected network forms a non-blocking structure, even if there is a link
If a fault occurs, the network can still be smooth. During data distribution, a piece of data is evenly divided into equal segments based on the number of nodes, and the parity characteristics of the data are calculated. Store each segment to the hard disk of each node
And the parity of the data. When a node fails, use the parity feature of the data of the other nodes and the parity feature of the block to perform an appropriate XOR operation, real-time data loss
It is restored without any loss. This technology is called raid2 technology. Therefore, if any node or connection fails, the broadcast will continue. This is a highly competitive technology.

Because of the unique and advanced seachange technology, seachange Reduces storage requirements and improves the effective storage capacity by almost twice compared with the dual-host backup method. It brings three benefits:

1) When data on any node fails, you can recover the data on the faulty node without interrupting normal broadcast;

2) data recovery of faulty nodes is to automatically re-write data from other nodes to this node to achieve self-recovery of faulty nodes;

3) during system expansion, data is automatically and evenly distributed to each node through system network management, enabling online expansion.

3. bmle

Bmle is a new generation of seachange and a central storage body for digital broadcast systems. It is based on the mediacluster structure and uses raid2 protection technology. The smallest scale is
Three nodes, with a maximum of nine nodes. This system uses five nodes for uploading and four nodes for broadcasting. Each node is configured with 24 10000-to-SCSI hard disks, with a single disk capacity of GB to GB.
Type. Each node is equipped with four FSI Gigabit IP acceleration cards for external network connections. nodes are connected through the InfiniBand Architecture to achieve fast data collection and distribution.

Bmle

4. mediaclient

Mediaclient is a new-generation codec platform of seachange. It supports multiple encoding formats (DV, dvcpro, MPEG2, MPEG4
. Mediaclient itself does not contain a storage body, and can be connected to any central storage body as needed. The central storage body bmle is output to the switch-over platform through mediaclient.
Program signal.

Mediaclient media client platform

The mcl4012 used for uploading is a SD server that uses one-way input and two-way output channels.

 

 

Seachange Video Server System Overview-[2]

Http://www.video.com.cn/tech/server/200804/1209002022638.html

Video.com.cn (video network) Source: China Digital TV

Ii. seachange Video Server System Structure

Seachange video server system adopts the upload/broadcast Separation Scheme

The dual seachangebmle24004 Video Server is used for broadcasting. This allows you to store images and shared channel backups, and only store the files to be played.

The upload storage level is public, and the dual seachangebmle24005 Video Server is used as the centralized storage and transmission area of the multicast Material file. The whole broadcast system and other external systems (nearline
The file exchange of storage, data library, advertising department, and so on is carried out through the storage-level bmle. Make full use of the advantages of high bandwidth, low cost, capacity expansion, and high bandwidth growth space of bmle.

The network topology of this solution is as follows:

Network Topology

1. Broadcast-level bmle

The broadcast level undertakes the task of broadcasting the active and standby images of 20 SD channels. It consists of the seachange4 node Media Database bmle24004 and 10 mediaclient. Due to the special requirements of broadcast-level security, its file source is only provided at the upload level.

Storage Capacity

Each node of the broadcast-level bmle24004 is configured with a stable and high-speed professional 146 GB hard disk group, with an effective storage capacity of up to 8 TB. Storage of full images for all 20 SD channels.

Security level

Many measures have been adopted at the broadcast level to improve the broadcast security level. These measures include:

Patented raid52 Technology

Two cluster Master/Slave Images

Store material backup in the transport-level bmle if necessary

Data Stream tape data backup

Seachange Video Server System Overview-[3]

Http://www.video.com.cn/tech/server/200804/1209002063341.html

Video.com.cn (video network) Source: China Digital TV

2. Upload storage and transfer-level bmle

The upload cluster simultaneously uploads programs and the central storage of files. Use seachange's 5-node Media Database Cluster bmle24005. As the storage and transmission center of multicast materials, bmle plays an important role in four aspects:

A) Collect and save recently needed broadcast materials from the upload level, data stream tape library, data library, and advertising department;

B) Upload Unarchived broadcast materials to the nearline storage system consisting of the data stream tape library for archival storage;

C) according to the broadcast level requirements, the broadcast-ready materials will soon be delivered to the broadcast level for storage;

D) provide third-party security protection for important materials to be broadcast.

Storage Capacity

Each node is configured with 24 hard disks and dual raid controllers. It is configured with a 10000 to GB dedicated SCSI hard disk group. The effective storage capacity of the 5-node bmle cluster is 11 TB.

The seachangebmle media database system supports the online upgrade mode, that is, nodes can be expanded without affecting normal operations. In this way, the system can be flexibly expanded to 6 nodes, 7 nodes, or
9-node cluster. In addition, because the bmle design mode is a central storage, dual clusters, three clusters, or more can be bound to a storage pool. Therefore, as a media database, bmle can expand its storage capacity.
Is extremely large.

Iii. Actual operations on the video server

The following figure shows the status structure of the seachange Video Server. The detection interface uses different colors (green, yellow, and red) To differentiate node states. Green indicates normal operation, yellow indicates a fault reminder, and red indicates a serious fault warning.

Alerts of different colors provide convenient conditions for operators and manufacturers to quickly and intuitively understand the current running status of the entire cluster.

Example of operations on the video server

You can see a total of five nodes in the middle. The node names are cctvi4n0, cctvi4n1, cctvi4n2, cctvi4n3, and cctvi4n4 (upload level ).

Seachange Video Server System Overview-[4]

Http://www.video.com.cn/tech/server/200804/1209002452310.html

Video.com.cn (video network) Source: China Digital TV

The connection between nodes is normal through the green solid line. If there is no connection between nodes, the node is disconnected from the cluster.
The following shows the status of each node:

Display the status of each node

After a node is selected, you can go to the detection page of the node. For example, the basic information of a node can be displayed on the detection interface and its sub-menu:

1. Display of the fan, power supply, and temperature status. If there is a problem with the fan and power source, a yellow color alarm will be displayed.

2. node connection status, with the color of the outer frame.

White: organize internal files.

Gray: connected to other nodes.

Green: The status is normal.

Yellow (all nodes): Check the entire cluster file.

Yellow (single node): checks the file of a single node.

Orange: nodes are not connected to the entire cluster.

RED: disconnects from the cluster.

3. Connection status of the Gigabit accelerator card

4. Hard Disk status and error count

5. Storage content

6. Other data records

Example of operations on the video server

Failure or failure of all hard disks can be displayed on this interface, reducing the workload of operator inspection.

To sum up, seachange's Video Server System is a broadcast system that uses the bmle media database as the central storage and mediaclient media client platform as the core, providing better security and stability, this has brought CCTV programs to a new level.