Oracle Video Server Administrator's Guide: UNIX
Release 2.1.7.3
A42271_4

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Chapter 7
Oracle Video Server Components Reference

Topics in this chapter are:

System-wide Command Line Options

The following command line options are available to all Oracle Video Server (OVS) executables:

-h

shows syntax for a utility.

-P

specifies the resource file. See "Using Resource Descriptors" later in this chapter.

-R

sets the specified resource descriptor. See "Using Resource Descriptors" later in this chapter.

-T

enables verbose mode. Verbose mode returns more information about actions performed by utilities.

-V

shows the release version.

Using Resource Descriptors

Every OVS command is associated with a list of resources. An OVS resource can be set as a UNIX environment variable to define a specific behavior when you execute a command. For example, you can set the resource foo.verbose=true to print any extra information when you invoke the foo command:

% setenv foo.verbose=true

The resource descriptor (verbose in the above example) is an element in the resource database of a process. Each resource descriptor is identified by a name and may have one or more values associated with it. These values are represented as character strings.

The name of a resource uses the following syntax:

command.resource

or, if the resource has a value:

command.resource=value

Unsetting Resource Descriptors

To remove a resource unset the environment variable defined for it. For example:

% unsetenv foo.verbose=true

Specifying Resources on the Command Line

Each OVS command has two options that are associated with resources: -R and -P. The -R option specifies a specific resource on the command line. For example, to set the verbose resource for vstag command to true:

% vstag -R vstag.verbose=true 

Multiple resources can be grouped together into resource files. The -P option specifies which resource file to use when you invoke a command. For example, you might group a number of resources descriptions in a file named myresources. If, for example, you wish to invoke the vstag command under the conditions described by the resource descriptions in myresources, use the
-P option:

% vstag -P myresources

The Oracle Video Server Components and Configuration Files

The following software components are started by the script ovsstart as described in the "Operating the Oracle Video Server" chapter. To ensure proper startup you should always use the ovsstart shell script to start these components. To provide a better understanding of the OVS's operation, and the command line options available to each OVS process, they are listed here in the order they are started.

mnaddrsrv  

OMN (Oracle Media Net) address server maps Media Net addresses to corresponding physical addresses.  

mnrpcnmsrv  

OMN name server maps the names of server processes to their Media Net addresses.  

mnprocsrv  

OMN process server receives RPC service requests from clients that are intended for the stream service or other application services and routes these messages to a process that services the request.  

mnlogsrv  

OMN logger process writes system and trace messages to its logfile for all OVS and OMN components.  

voltab  

Configuration file that defines the Oracle Media Data Store (MDS) volume structure.  

mdsdirsrv  

MDS directory server. Manages the layout of files in the MDS and grants access permission to requesting clients (such as vspump), to create, access, or modify files. mdsdirsrv also determines if there is bandwidth available to allow a client access without losing the service quality to clients already accessing
the MDS.  

mnocs  

Connection service maps physical addresses of clients to physical downstream addresses on the server computer.  

vsstrmsrv  

Stream service handles requests for content files from a client, including operations such as play, pause, stop, and rewind.  

vspump  

Video pump reads content files from the MDS and streams the requested data to clients over the network.  

vscontinf  

Video content manager allows a client to query all mounted MDS volumes and obtain a listing of files.  

Note

Many of the OVS components support options not used in a corporate LAN environment. While these options will appear in the on-line help, you should not use them with this version of the OVS. In this chapter, these options are explained to provide a better understanding of the OVS and its capabilities.

mnaddrsrv

mnaddrsrv (OMN address server) maps Media Net addresses to corresponding physical addresses. When a server process starts, it requests a Media Net address from and registers its corresponding transport layer address with the address server.

Syntax

mnaddrsrv [-i media_net_address] [-e {console | screen}] [-D] 

where:

-i

specifies the OMN IP address and port number ($OMN_ADDR).

-e

specifies how the address server reports errors:

console

writes to the default system log.

screen

writes to the terminal screen.

-D

prevents the address server from invalidating the Media Net addresses of inactive processes. Each process sends a Media Net heartbeat message to the address server each minute. If you omit -D, the address server invalidates the address of any process from which it has not received a heartbeat message in the last 3 minutes.

Note

Use -D only if you are debugging or if you plan to be idle at the client device emulator for more than 3 minutes. Do not use -D in a production OVS system.

Example

To start mnaddrsrv, use the following command:

mnaddrsrv -i $OMN_ADDR &

mnrpcnmsrv

mnrpcnmsrv (OMN name server) maps the names of server processes to their Media Net addresses. When a server process is started, it registers its name and Media Net address with the name server. Before a client can send a message to a server, the client first contacts the name server to find the server's Media Net address.

Syntax

mnrpcnmsrv [-e {console | screen}]

where:

-e

specifies how the address server reports errors:

console

writes to the default system log.

screen

writes to the terminal screen.

Example

This example shows mnrpcnmsrv writing to the system log file:

% mnrpcnmsrv -e console &

mnprocsrv

mnprocsrv (OMN process server) receives RPC service requests from clients that are intended for the stream service or other application services and routes these messages to a process that services the request.

Syntax

mnprocsrv [-e {console | screen}]

where:

-e

specifies how the address server reports errors:

console

writes to the default system log.

screen

writes to the terminal screen.

Example

This example shows mnprocsrv writing to the system log file:

% mnprocsrv -e console &

mnlogsrv

mnlogsrv (OMN logger process) writes system and trace messages to its logfile for all OVS and OMN components. It is useful for troubleshooting the OVS system. For a list of the messages written by the logger process, see the Oracle Video Server Logger Messages manual.

Syntax

mnlogsrv [-m /path/file] [-s | -f /path/file [-r integer]

                [-h integer] ] [-n name] [-l integer] 

where:

-m

identifies the message file that mnlogsrv uses to map error numbers to error messages. The default is mzlm.dat in the
$ORACLE_HOME/vs21/mesg/ directory.

-s

routes messages to the console if possible.

-f

identifies the file to which mnlogsrv writes messages.

The -s and -f switches are mutually exclusive. If you omit both, mnlogsrv writes to the console.

-r

limits how many bytes of data mnlogsrv writes to the log file before beginning to write to another. When the logger reaches the end of a file, it renames the file by giving it the file extension .1. If past log files already exist, mnlogsrv renames each by incrementing its file extension (.1 becomes .2, .2 becomes .3, etc.) until the limit specified by -h.

The -r and -h switches are useful only if you use -f.

The default is 1 MB and the minimum is 1000 bytes.

-h

specifies the number of past log files mnlogsrv keeps. The default
is 1.

-n

specifies a single OVS component for which mnlogsrv writes messages. This switch is useful for testing individual components. You can identify a component either by its name as registered in the name server or by its OMN address as registered in the address server. You can start multiple mnlogsrv processes with -n to test multiple components.

If you omit -n, mnlogsrv writes messages for all OVS components.

-l

specifies a message logging level. The mnlogsrv process only writes messages with severity levels not exceeding the -l value, so a larger -l value causes mnlogsrv to write more messages. The minimum is 1 which writes only emergency messages, and the maximum is 7 which writes all messages. The default and recommended level is 6.

The message logging level determines how important a system event must be in order to be logged. Select the least important message level you want to be logged. Note that logging more system messages may reduce the performance of the OVS.

Table 7-1:

1  

Emergency  

2  

Action must be taken  

3  

Critical  

4  

Error, operation unsuccessful  

5  

Warning, operation completed  

6  

Normal but significant (default)  

7  

Informative message  

Message logging levels

Example

This example starts mnlogsrv for all OVS components using the message file mzlm.dat in the directory $ORACLE_HOME/mesg and the log file mzlog in the directory $ORACLE_HOME/vs21/log providing the most information:

% mnlogsrv -m $ORACLE_HOME/vs21/mesg/mzlm.dat \

-f $ORACLE_HOME/vs21/log/mzlog -l 7 &

voltab

The voltab configuration file defines the Oracle Media Data Store (MDS) volumes that mdsdirsrv can access. The Oracle Installer creates a voltab file for one volume at installation. If you require additional MDS volumes, or wish to alter your MDS configuration, you must modify this file. Before starting mdsdirsrv (MDS directory server), you must create a voltab configuration file.

Syntax

volume [maxbw={integer},] [maxrate=integer,] [minrate=integer,]
[
dfltrate=integer,] striped, [width=integer,][noparity,]
[
raidsize=integer,][tocsz=integer,][spares=disk_name] disks ...

where:

volume

the name of the MDS volume. Volume names can be from 1 to 32 characters long.

maxbw

specifies the maximum rate in megabits per second (Mbps) at which all OVS components can together read and/or write to the MDS volume.

dfltrate

specifies the maximum default bit rate allocated to a non-real-time MDS client in Mbps. This is used whenever non-real-time MDS clients request the default bit rate.

maxrate

specifies the maximum bit rate allocated to a non-real-time MDS client in Mbps. This is used whenever non-real-time MDS clients request the maximum allowable bit rate. If maxrate is not specified, dfltrate and minrate are not applicable.

minrate

specifies the minimum bit rate allocated to a non-real-time client (unless the client requests less). As more clients access the MDS, the server allocates less and less bandwidth to non-real-time clients until all available bandwidth is used. The minrate parameter specifies the minimum bit rate that must be available for the allocation of resources to an MDS client.

striped

stripes all files in the MDS volume across all the volume's disks. MDS volumes must be striped.

width

specifies the stripe width. The default stripe width is 32K.

noparity

disables RAID protection but organizes the volume into RAID sets of the size specified by raidsize and performs I/O to all disks as if in a RAID set. To disable RAID protection, use a raidsize of 1 rather than noparity.

raidsize

specifies the number of disks in a RAID set. The default, and minimum, raidsize is 1, which disables RAID protection. A raidsize greater than 1 enables RAID protection. Do not use a raidsize greater than 6, since this would adversely affect the maxbw value.

tocsz

specifies the size of the volume's table of contents in raidstripes. Increasing this value increases the maximum number of files that can be stored in a volume. The size of a raidstripe is width x raidsize. The minimum, default, and recommended value is 1; there
is no maximum.

spares

specifies which disk, if any, is to be used as a spare in the event of a
disk failure. Each volume can have one and only one spare disk. Spares are not necessary on systems that support hot-swappable disks.

disks

specifies the disks in the volume, whose number must be a multiple of raidsize. Disks should be listed in one of the following ways:

Note

Refer to Chapter 2, "System Planning for the Oracle Video Server" of the Oracle Video Server Administrator's Guide for information on calculating the following voltab file parameters:

Real-Time and Non-Real-Time Volumes

When you create a voltab file using the maxbw value, the MDS volume you define is a real-time MDS volume. A real-time MDS volume limits the access of clients to ensure real-time delivery of video data. If a client request would overload the volume and adversely affect the quality of service, mdsdirsrv denies the request. Production OVS systems should always use real-time volumes for video delivery.

If the maxbw value is omitted from the voltab file, the MDS volume is a non-real-time MDS volume. A non-real-time volume does not limit access regardless of the number of client requests. Generally, you should not use a non-real-time volume to deliver video as the quality of service may be poor if too many concurrent requests are received.

In a real-time volume, bandwidth is allocated to non-real-time clients based on the voltab parameters dfltrate, maxrate, and minrate. These values rarely need to be specified since they have optimal system-dependent defaults. These parameters are explained in more detail later in this section.

Obtaining the maxbw Value

To obtain an accurate maxbw value for your MDS volume, use the mdsvstat utility. Refer to the "Media Data Store Utilities" chapter of the Oracle Video Server Utilities User's Guide (online only) for more information on mdsvstat and its usage.

Defining Multiple MDS Volumes

The Oracle Video Server Installation Guide for your server platform explains the proper disk notation for listing disks to be used in a volume. This example shows a voltab file with multiple volumes listed.

Example 1

This example defines two real-time MDS volumes (volume1 and volume2).

volume1 maxbw=184,striped,width=32k,raidsize=4, \
/dev/rdsk/c{0-3}t{0-3}d0s{6}
volume2 maxbw=184,striped,width=32k,raidsize=4, \
/dev/rdsk/c{4-7}t{0-3}d0s{6}

Example 2

This example defines three MDS volumes. The first and second (volume1 and volume2) have maxbw values; making them real-time volumes. The third (volume3) does not yet have a maxbw value, making it a non-real-time volume:

volume1 maxbw=184,striped,width=32k,raidsize=4, \
/dev/rdsk/c{0-3}t{0-3}d0s{6}
volume2
maxbw=184,striped,width=32k,raidsize=4, \
/dev/rdsk/c{4-7}t{0-3}d0s{6}
volume3 striped,width=32k,raidsize=4, \
/dev/rdsk/c{8-11}t{0-3}d0s{6}

Initializing the Oracle Media Data Store

Use the mdsvolinit utility to write the definition for each MDS volume in the voltab file to its disks. Perform this step only:

This example command writes all of the volume definitions from voltab in the directory $ORACLE_HOME/vs21/admin to the volume video and erases all content:

% mdsvolinit -s -t -f $ORACLE_HOME/vs21/admin/voltab video

Caution

This will erase all content from the specified volume. Once an MDS volume has been initialized, its properties (i.e. disk configuration, stripe width, raidsize) cannot be modified without destroying all the volume's content. If you wish to modify an MDS volume, first back up all of its content, so it can be reloaded into the modified volume.

For more information on mdsvolinit, refer to Chapter 2, "Oracle Media Data Store (MDS) Utilities" in the Oracle Video Server Utilities User's Guide.

Remember to back up your modified voltab file.

mdsdirsrv

mdsdirsrv (media data store directory server) manages the layout of files in the MDS and grants access permission to requesting clients (such as vspump), to create, access, or modify files. mdsdirsrv also determines if there is bandwidth available to allow a client access without losing the service quality to clients already accessing the MDS.

Syntax

mdsdirsrv [ -b disk...] -f $ORACLE_HOME/vs21/admin/voltab

[-r volume-name...] [-i volume-name...] [-w volume-name...] [-I]

[-R ] [-W]

where:

-b

suppresses error messages resulting from accessing the specified disks when mdsdirsrv starts. If you want mdsdirsrv to access volumes containing failed disks, you must specify these disks with -b; this alerts administrative users that the volume contains failed disks, but allows the volume to be used if the data is parity protected.

-f

identifies the voltab file that defines the volume(s) to be accessed
by mdsdirsrv.

-i

mounts the specified volume in inconsistent read-only mode.

-I

mounts all volumes specified in the voltab file in inconsistent read-only mode, except those volumes specified by -r or -w.

-r

mounts the specified volume in read-only mode.

-R

mounts all volumes specified in the voltab file in read-only mode, except those volumes specified by -i or -w.

-w

mounts the specified volume in read-write mode

-W

mounts all volumes specified in the voltab file in read-write mode, except those volumes specified by -i or -r.

Read-Write Modes

MDS volumes can be mounted in the following read-write modes:

Read-write mode

A volume mounted in read-write mode allows mdsdirsrv to both read and write to the volume.

Read-Only and Inconsistent Read-Only Mode

A volume mounted in read-only or inconsistent read-only mode allows mdsdirsrv to read but not write to the volume.

Multiple mdsdirsrv processes can mount an MDS volume in inconsistent read-only mode or read-only mode. If you are running multiple OVS servers, each with a mdsdirsrv process, only one OVS server can mount an MDS volume in read-write mode.

A volume mounted in inconsistent read-only mode allows mdsdirsrv to read a volume that is being modified by a read-write mode mdsdirsrv process from a different server. The inconsistent read-only mdsdirsrv process will receive periodic updates about the volume changes made by the read-write mdsdirsrv process, however, at times the inconsistent read-only mdsdirsrv process will not see the correct volume image. When this happens the inconsistent read-only mdsdirsrv process may allow its clients to open up files that do not actually exist and whose contents are indeterminate. In addition, it may not know about files that have been recently created.

Note

In a production OVS system, you should not have more then one mdsdirsrv process accessing an MDS volume unless you are debugging the OVS.

Usage Notes

While starting, mdsdirsrv recognizes any failed disks in the MDS volume and writes messages identifying them to the console and the OVS log file. You can recreate data onto a new disk with the mdsrebuild utility. For information on mdsrebuild, refer to Chapter 2, "Oracle Media Data Store (MDS) Utilities" chapter in the Oracle Video Server Utilities User's Guide.

Examples

Example 1

This example command starts mdsdirsrv, allowing it to read and write the MDS volumes specified in the voltab file located in the directory
$ORACLE_HOME/vs21/admin:

% mdsdirsrv -W -f $ORACLE_HOME/vs21/admin/voltab

Example 2

This example mounts all volumes in read-write mode, except for the volume training, which is mounted in read-only mode:

% mdsdirsrv -W -r training -f $ORACLE_HOME/vs21/admin/voltab

Example 3

In this example, the volume video is mounted in inconsistent read-only mode; all other volumes in the voltab file will be mounted in read/write mode:

% mdsdirsrv -W -i video -f $ORACLE_HOME/vs21/admin/voltab

If a volume is mounted by two servers, only one server can mount the volume in read-write mode, the other server must mount the volume in inconsistent-read-only mode. Note that if a volume is mounted by two servers, video cannot be streamed from that volume with real-time constraints.

mnocs

mnocs (connection service) maps physical addresses of clients to physical downstream addresses on the server computer.

Syntax

mnocs -a 

where:

-a

dynamically chooses downstream mangers

Example

To start mnocs, use this syntax:

% mnocs -a &

vsstrmsrv

The stream service (vsstrmsrv) handles requests for content files from a client. When the stream service receives a request for a video content file, it reads the tag file associated with the requested video file in the Media Data Store (MDS). It then sends a message to the video pump indicating that a client has requested the file.

Syntax

vsstrmsrv -n integer

where:

-n integer

the maximum number of clients that can concurrently connect to the stream service. The default is 100.

Example

This example starts the stream service and sets the maximum number of concurrent client connections to 30:

% vsstrmsrv -n 30 &

vspump

The vspump (video pump) reads files from the MDS and sends the requested video data to clients over the network.

Syntax

vspump [-a] [-b integer] [-c integer] [-C] [-d] [-D] [-f] [-F]

[-g] [-m integer] [-n integer] [-N integer ] [-o address] [-p]

[-q] [-s] [-S] [-t] [-x] [-y] 

where:

-a

wraps data in Oracle generic format.

Note

When operating in a corporate LAN, -a must be specified.

-b

specifies the maximum data transmission rate per stream in Mbps per stream for the video pump. The default maximum is 2.05 Mbps.

-c

specifies the amount of memory in bytes per stream which hold data that the video pump reads from the MDS before sending it.

-m

specifies the maximum number of video streams the video pump can serve.

-n

chooses the size in bytes of the output buffer. When using the OVS in a corporate LAN, the packet size should be 8192 bytes.

-N

specifies the number of packets the video pump transmits at a time. The default is one and the maximum is four.

-o

specifies the downstream manager physical address to which the video pump binds. This is the IP address and a port number used by the server, for example:

dUDP:144.25.101.147:5000

where 144.25.101.147 is the IP address of the server and 5000 is the UDP port number.

-q

suppresses banner and downstream configuration information normally written by the video pump at start-up. If you are starting several video pumps at once, -q prevents them from filling the log file with this information.

-S

suppresses the use of super packets. If -S is omitted the video pump sends several packets as one.

Note

When operating in a corporate LAN, -S should always be specified.

-t

specifies that the video pump operate as a real-time client to the Media Data Store on Solaris platforms. This option should always be used on Solaris platforms to specify real-time scheduling and to lock down the memory required for the video pump.

-y

allows an instance of the video pump to bind to a CPU for its exclusive use. This allows the video pump to make better scheduling decisions than if it shares the CPU with other processes. When operating the Oracle Video Sever on a multi-processor platform, you will generally want to specify the -y option.

Note

Do not specify this option on single-processor servers.

Caution

Do not use the following options when using the OVS in a corporate LAN environment. These options are intended for use in deployments which include interactive television, and do not apply to video supplied over a local-area network.

-C

transmits data without wrapping it in either Oracle generic or MPEG 2 format.

-d

allows you to operate the video pump without sending video data to a client for testing purposes.

-D

writes messages to the log file containing all of the MPEG-2 data the video pump transmits.

-f

specifies that the video pump flips the bits of its video. The default is not to flip bits.

-F

increases the throughput for downloading cards. Each card is stored in the MDS volume in MPEG packets. This option bundles many packets together and sends them to the client device at once. If you omit this option each packet is sent separately.

-g

wraps data in CD Interactive (CDI) format.

-p

sends nulls before application data to the client device.

-s

specifies that the video pump send packets as fast as possible.

-x

specifies rigid scheduling.

Example

The following example starts vspump with 5 streams per instance and a bit rate of 2.05 Mbps:

% vspump -a -S -o dUDP:127.0.0.1:12000 -m 5 -b 2.05 -n 8192 &

vscontinf

vscontinf (video content manager) allows a client to query all mounted MDS volumes and obtain a listing of files.

Syntax

vscontinf

vscontinf takes no arguments and operates as a background process.

Example

The following example starts vscontinf:

% vscontinf &




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