JP2000148711A - Dynamic image server system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic image server system which is small in system configuration and low in cost by reducing number of systems of a network. SOLUTION: Streams read out of file servers at a request from a client are supplied to the interface circuit of a stream sending-out device through the network. The stream sending-out device detects a fault of the supplied streams and repairs the stream where the fault is detected. The stream sending- out device performs a connecting processing for the repaired stream to generate one stream, outputs the stream to the network through the interface circuit, and sends the stream outputted from the interface circuit to the client through the network.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a moving picture server system for providing a plurality of compressed / uncompressed moving pictures and sounds.

[0002]

2. Description of the Related Art A plurality of VODs (V
A video on demand (Video on Demand) server is used to perform video processing in parallel with a VOD server by performing parallel processing. The following method is used.

(1) In-server RAID system In one server, a RAID (Redundant Arrays of Independent Diode) comprising a plurality of HDDs (Hard Disk Drives) is provided.
sks: A disk array that connects disks and provides more than one HDD. Stream transmission exceeding the capacity of one server is realized by arranging the same stream on a plurality of servers.

(2) RAID method between servers As shown in Japanese Patent Application Laid-Open No. 9-205634, this is a method in which one stream is divided into a certain length and arranged cyclically on a plurality of servers. . Compared to the in-server RAID method (1), this method uses a method such as a time slot to prevent concentration on a specific server because multiple servers read one stream in parallel. However, if the load distribution is successful, the installation space for the HDD can be reduced. When reading stream data from a file server, one file server constitutes a part of a file system that stores stream data. Therefore, the stream transmission device accesses the file server group constituting the file system in units of logical blocks, and the stream transmission device interprets the file system.

(3) Further, as another method which is an improvement of the above two methods, as shown in FIG. 3, a file server and a stream transmission device are connected via a server area network, and a connection between the stream transmission device and the client is established. There is also a method of connecting via a client area network.

[0006]

However, in the method shown in FIG. 3, a network connecting file servers and
Two networks, a network connecting the file server and the client, were required. In addition, focusing on the flow of the stream, the stream transmission device performs only the reception of the stream on the server area network side, and performs only the transmission of the stream on the client area network side. Therefore, the stream transmitting apparatus needs to provide a receiving port and a transmitting port separately. As described above, in the conventional system, it is inevitable that the system configuration becomes large, and it is difficult to make the system inexpensive. SUMMARY OF THE INVENTION It is an object of the present invention to provide a moving image server system in which the number of network systems is reduced and the system configuration is reduced in size and cost.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of distributing a plurality of stream files generated by performing division processing in advance and storing the stream files in respective file systems. File server and
A plurality of streams read from the plurality of file servers in response to a request from a client are supplied to an interface circuit via a network, a failure of the supplied plurality of streams is detected, and the stream in which the failure has been detected. Is repaired, the repaired stream and the stream in which no failure is detected are subjected to connection processing and output as one stream to the network via the interface circuit, and the stream output from the interface circuit is passed through the network. And a transmitting device for transmitting the moving image to the client.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention enables transmission and reception of a stream of a transmission device by the same port (the same interface circuit) so that the number of network systems can be reduced.

FIG. 1 shows an embodiment of a live video server system.
FIG. 2 shows a more detailed configuration of each part of the embodiment shown in FIG. Each file server has a file system for distributing and storing a plurality of stream files generated by performing a division process in advance. However, when a mirror operation is performed by a stream transmission device to be described later, stream files having the same contents are redundantly stored in a plurality of file systems without performing division.

[0010] Each stream transmission device is connected to a network via an interface (I / F) circuit. Each stream transmission device transmits and receives a stream according to a request from a client via this interface circuit. File server, stream sending device,
The client and the client are connected by one network.

The file server operates according to the POSIX-compliant UNIX protocol, and the read process circuit in the file server operates as a user process. The stream file stored in the file system is opened by an open system call from the read process circuit, and is read by a read system call. This is the same as a normal file operation. The stream file read by the read system call is temporarily stored in a FIFO buffer in the file server, and then sent from the sending process circuit to the stream sending device via the network.

The stream sending device includes a receiving process circuit, a FIFO buffer, a sending process circuit, and an interface circuit. The stream sending device receives the stream sent from the file server by the receiving process circuit through the interface circuit, sends the stream to the network via the FIFO buffer, the sending process circuit, and the interface circuit, and supplies the stream to the client. .

The FIFO buffer in the file server and the stream sending device is a shared memory, which is one of the UNIX protocol inter-process communication functions.
A ring buffer is formed according to the method. This shared memory system uses an OS from a file server and a main storage unit (RAM) of a stream transmission device.
Is assigned, so that it can be assigned with an optimal size according to the speed at which the stream flows and the speed at which the file is read.

The reading process circuit in the file server schedules the reading order based on the vacant ratio of the FIFO buffer. As another calculation method of the scheduling, the calculation can be performed based on the free space of the FIFO buffer and the speed at which the stream flows, or the size read by the read process circuit at one time. In this case, different stream speeds can be mixed. The read process circuit on the file server supplies the data read by the read system call to the FIFO buffer corresponding to the result of the scheduling in accordance with the above-mentioned scheduling.

The sending process circuit in the file server includes:
Running as a user process. The sending process circuit reads data from the FIFO buffer and sends a network stream to the network. When transmitting a stream to a network, there are two methods for controlling the transmission rate. A first method of controlling on the file server side at a stream bandwidth reserved rate;
The second method is based on flow control from the reception process circuit of the stream transmission device. The second method, the flow control method, is based on the TCP / IP protocol (OSI
(4th layer of the reference model) and OSI over UDP / IP
There is a method performed in the fifth layer session layer or the seventh application layer of the reference model.

The stream sending device is a POSIX compliant UNIX.
It operates according to the protocol, and the receiving process circuit in the stream sending device operates as a user process. The receiving process circuit receives the network stream transmitted from the transmitting process circuit in the file server from the network via the interface (I / F) circuit, and stores the network stream in the FIFO buffer in the stream transmitting device.

When the flow control of the network stream is performed between the file server and the stream transmission device, the reception process circuit in the stream transmission device checks the availability of the FIFO buffer in the stream transmission device.

The transmission process circuit of the stream transmission device operates as a user process. The sending process circuit reads out the stream data from the plurality of FIFO buffers and detects a failure, and then performs a connecting process to form one stream. Then, the transmission process circuit transmits the stream subjected to the connection processing to the network via the same interface (I / F) circuit as at the time of reception.
The client receives the transmitted stream via the network and reproduces an image.

The transmission process circuit of the stream transmission device performs a RAID operation between the read data when reading the stream data from the plurality of FIFO buffers. Further, the sending process circuit detects a failure in the stream data based on the remaining amount of the plurality of FIFO buffers. When a failure occurs, the transmission process circuit restores the stream data according to a predetermined procedure and continues data transmission. As a method of continuing data transmission when a failure occurs, RA
There are a method based on ID parity, a method for switching to an alternative file server having the same stream data, and a method for switching to a low bit rate stream by using a stream input having no failure among a plurality of stream inputs.

The following is a summary of the moving image server system for each of the above three continuation methods. A plurality of stream files generated by performing parity processing and division processing in advance, a plurality of file servers that are distributed and stored in their respective file systems, and in response to a request from a client, A plurality of streams read from a plurality of file servers are supplied to an interface circuit via a network, a failure of the supplied plurality of streams is detected, and the detected stream is repaired using parity, The repaired stream and the stream in which no failure is detected are subjected to connection processing, output as one stream to the network via the interface circuit, and the stream output from the interface circuit is sent to the client via the network. Transmission device A moving image server system characterized by the following.

An embodiment adopting the method of (1) A plurality of file servers each having a file system storing a stream of the same contents, and a plurality of the same contents read from the plurality of file servers in response to a request from a client. Stream is supplied to the interface circuit via the network, a failure of the supplied plurality of streams having the same content is detected, and when a failure is detected in the stream from one file server, the connection is already established. And a stream transmitting device for continuously transmitting a stream from the interface circuit to the client without stopping the transmission to a client by switching to a path of another file server.

An embodiment adopting the method of (1) A plurality of file servers that distribute and store a plurality of stream files generated in advance by division processing in their respective file systems, A second server that sends out streams and a plurality of streams read from the plurality of file servers in response to a request from a client are supplied to an interface circuit via a network, and a failure of the plurality of supplied streams is performed. And when a failure is detected,
A stream sending device that continuously sends a stream from the interface circuit to the client by stopping the sending to the client by switching from the normal quality to a low quality stream by switching to the second server. A moving image server system, characterized in that:

[0023]

As described above, in the moving picture server system of the present invention, the transmission and reception of the stream of the transmitting device can be performed by the same interface circuit, so that the network system can be reduced, the system configuration can be reduced in size and the system configuration can be reduced. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment.

FIG. 2 is a diagram showing a more detailed configuration of each unit of the embodiment shown in FIG.

FIG. 3 is a diagram showing a conventional example.

Claims (1)

[Claims] 1. A plurality of file servers for distributing a plurality of stream files generated by performing division processing in advance and storing them in respective file systems, and the plurality of file servers in response to a request from a client. Are supplied to the interface circuit via the network, detect a failure in the supplied streams, repair the stream in which the failure is detected, and detect the repaired stream and the failure. A transmission device for performing connection processing on the stream that has not been output, outputting the stream as one stream to the network via the interface circuit, and transmitting the stream output from the interface circuit to the client via the network. A moving image server system characterized by the following.