.\" -*- nroff -*-
.de IQ
.  br
.  ns
.  IP "\\$1"
..
.TH ovsdb\-server 1 "2.3.0" "Open vSwitch" "Open vSwitch Manual"
.\" This program's name:
.ds PN ovsdb\-server
.
.SH NAME
ovsdb\-server \- Open vSwitch database server
.
.SH SYNOPSIS
\fBovsdb\-server\fR
[\fIdatabase\fR]\&...
[\fB\-\-remote=\fIremote\fR]\&...
[\fB\-\-run=\fIcommand\fR]
.IP "Daemon options:"
[\fB\-\-pidfile\fR[\fB=\fIpidfile\fR]]
[\fB\-\-overwrite\-pidfile\fR]
[\fB\-\-detach\fR]
[\fB\-\-no\-chdir\fR]
.IP "Service options:"
[\fB\-\-service\fR]
[\fB\-\-service\-monitor\fR]
.IP "Logging options:"
[\fB\-v\fR[\fImodule\fR[\fB:\fIfacility\fR[\fB:\fIlevel\fR]]]]\&...
.br
[\fB\-\-verbose[=\fImodule\fR[\fB:\fIfacility\fR[\fB:\fIlevel\fR]]]]\&...
.br
[\fB\-\-log\-file\fR[\fB=\fIfile\fR]]
.IP "Public key infrastructure options:"
[\fB\-\-private\-key=\fIprivkey.pem\fR]
.br
[\fB\-\-certificate=\fIcert.pem\fR]
.br
[\fB\-\-ca\-cert=\fIcacert.pem\fR]
.br
[\fB\-\-bootstrap\-ca\-cert=\fIcacert.pem]
.IP "Runtime management options:"
\fB\-\-unixctl=\fIsocket\fR
.IP "Common options:"
[\fB\-h\fR | \fB\-\-help\fR]
[\fB\-V\fR | \fB\-\-version\fR]

.
.SH DESCRIPTION
The \fBovsdb\-server\fR program provides RPC interfaces to one or more
Open vSwitch databases (OVSDBs).  It supports JSON-RPC client
connections over active or passive TCP/IP or Unix domain sockets.
.PP
Each OVSDB file may be specified on the command line as \fIdatabase\fR.
If none is specified, the default is \fB/etc/openvswitch/conf.db\fR.  The database
files must already have been created and initialized using, for
example, \fBovsdb\-tool create\fR.
.
.SH OPTIONS
.
.IP "\fB\-\-remote=\fIremote\fR"
Adds \fIremote\fR as a connection method used by \fBovsdb\-server\fR.
\fIremote\fR must take one of the following forms:
.
.RS
.IP "\fBpssl:\fIport\fR[\fB:\fIip\fR]"
Listen on the given SSL \fIport\fR for a connection.  By default,
connections are not bound to a particular local IP address and
it listens only on IPv4 (but not IPv6) addresses, but
specifying \fIip\fR limits connections to those from the given
\fIip\fR, either IPv4 or IPv6 address.  If \fIip\fR is
an IPv6 address, then wrap \fIip\fR with square brackets, e.g.:
\fBpssl:6632:[::1]\fR.  The \fB\-\-private\-key\fR,
\fB\-\-certificate\fR, and \fB\-\-ca\-cert\fR options are mandatory
when this form is used.
.
.IP "\fBptcp:\fIport\fR[\fB:\fIip\fR]"
Listen on the given TCP \fIport\fR for a connection.  By default,
connections are not bound to a particular local IP address and
it listens only on IPv4 (but not IPv6) addresses, but
\fIip\fR may be specified to listen only for connections to the given
\fIip\fR, either IPv4 or IPv6 address.  If \fIip\fR is
an IPv6 address, then wrap \fIip\fR with square brackets, e.g.:
\fBptcp:6632:[::1]\fR.
.
.IP "\fBpunix:\fIfile\fR"
On POSIX, listen on the Unix domain server socket named \fIfile\fR for a
connection.
.IP
On Windows, listen on a kernel chosen TCP port on the localhost. The kernel
chosen TCP port value is written in \fIfile\fR.
.IP "\fBssl:\fIip\fB:\fIport\fR"
The specified SSL \fIport\fR on the host at the given \fIip\fR, which
must be expressed as an IP address (not a DNS name) in IPv4 or IPv6 address
format.  If \fIip\fR is an IPv6 address, then wrap \fIip\fR with square
brackets, e.g.: \fBssl:[::1]:6632\fR.
The \fB\-\-private\-key\fR, \fB\-\-certificate\fR, and \fB\-\-ca\-cert\fR
options are mandatory when this form is used.
.
.IP "\fBtcp:\fIip\fB:\fIport\fR"
Connect to the given TCP \fIport\fR on \fIip\fR, where \fIip\fR can be IPv4
or IPv6 address. If \fIip\fR is an IPv6 address, then wrap \fIip\fR with
square brackets, e.g.: \fBtcp:[::1]:6632\fR.
.
.IP "\fBunix:\fIfile\fR"
On POSIX, connect to the Unix domain server socket named \fIfile\fR.
.IP
On Windows, connect to a localhost TCP port whose value is written in
\fIfile\fR.
.
.IP "\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR"
Reads additional connection methods from \fIcolumn\fR in all of the
rows in \fItable\fR within \fIdb\fR.  As the contents of \fIcolumn\fR changes,
\fBovsdb\-server\fR also adds and drops connection methods accordingly.
.IP
If \fIcolumn\fR's type is string or set of strings, then the
connection methods are taken directly from the column.  The connection
methods in the column must have one of the forms described above.
.IP
If \fIcolumn\fR's type is UUID or set of UUIDs and references a table,
then each UUID is looked up in the referenced table to obtain a row.
The following columns in the row, if present and of the correct type,
configure a connection method.  Any additional columns are ignored.
.RS
.IP "\fBtarget\fR (string)"
Connection method, in one of the forms described above.  This column
is mandatory: if it is missing or empty then no connection method can
be configured.
.IP "\fBmax_backoff\fR (integer)"
Maximum number of milliseconds to wait between connection attempts.
.IP "\fBinactivity_probe\fR (integer)"
Maximum number of milliseconds of idle time on connection to
client before sending an inactivity probe message.
.RE
.IP
It is an error for \fIcolumn\fR to have another type.
.RE
.
.IP
To connect or listen on multiple connection methods, use multiple
\fB\-\-remote\fR options.
.
.IP "\fB\-\-run=\fIcommand\fR]"
Ordinarily \fBovsdb\-server\fR runs forever, or until it is told to
exit (see \fBRUNTIME MANAGEMENT COMMANDS\fR below).  With this option,
\fBovsdb\-server\fR instead starts a shell subprocess running
\fIcommand\fR.  When the subprocess terminates, \fBovsdb\-server\fR
also exits gracefully.  If the subprocess exits normally with exit
code 0, then \fBovsdb\-server\fR exits with exit code 0 also;
otherwise, it exits with exit code 1.
.IP
This option can be useful where a database server is needed only to
run a single command, e.g.:
.B "ovsdb\-server \-\-remote=punix:socket \-\-run='ovsdb\-client dump unix:socket Open_vSwitch'"
.IP
This option is not supported on Windows platform.
.SS "Daemon Options"
.ds DD \
\fBovsdb\-server\fR detaches only after it starts listening on all \
configured remotes.
The following options are valid on POSIX based platforms.
.TP
\fB\-\-pidfile\fR[\fB=\fIpidfile\fR]
Causes a file (by default, \fB\*(PN.pid\fR) to be created indicating
the PID of the running process.  If the \fIpidfile\fR argument is not
specified, or
if it does not begin with \fB/\fR, then it is created in
\fB/var/run/openvswitch\fR.
.IP
If \fB\-\-pidfile\fR is not specified, no pidfile is created.
.
.TP
\fB\-\-overwrite\-pidfile\fR
By default, when \fB\-\-pidfile\fR is specified and the specified pidfile 
already exists and is locked by a running process, \fB\*(PN\fR refuses 
to start.  Specify \fB\-\-overwrite\-pidfile\fR to cause it to instead 
overwrite the pidfile.
.IP
When \fB\-\-pidfile\fR is not specified, this option has no effect.
.
.TP
\fB\-\-detach\fR
Causes \fB\*(PN\fR to detach itself from the foreground session and
run as a background process. \*(DD
.
.TP
\fB\-\-monitor\fR
Creates an additional process to monitor the \fB\*(PN\fR daemon.  If
the daemon dies due to a signal that indicates a programming error
(\fBSIGABRT\fR, \fBSIGALRM\fR, \fBSIGBUS\fR, \fBSIGFPE\fR,
\fBSIGILL\fR, \fBSIGPIPE\fR, \fBSIGSEGV\fR, \fBSIGXCPU\fR, or
\fBSIGXFSZ\fR) then the monitor process starts a new copy of it.  If
the daemon dies or exits for another reason, the monitor process exits.
.IP
This option is normally used with \fB\-\-detach\fR, but it also
functions without it.
.
.TP
\fB\-\-no\-chdir\fR
By default, when \fB\-\-detach\fR is specified, \fB\*(PN\fR 
changes its current working directory to the root directory after it 
detaches.  Otherwise, invoking \fB\*(PN\fR from a carelessly chosen 
directory would prevent the administrator from unmounting the file 
system that holds that directory.
.IP
Specifying \fB\-\-no\-chdir\fR suppresses this behavior, preventing
\fB\*(PN\fR from changing its current working directory.  This may be 
useful for collecting core files, since it is common behavior to write 
core dumps into the current working directory and the root directory 
is not a good directory to use.
.IP
This option has no effect when \fB\-\-detach\fR is not specified.
.SS "Service Options"
The following options are valid only on Windows platform.
.TP
\fB\-\-service\fR
Causes \fB\*(PN\fR to run as a service in the background. The service
should already have been created through external tools like \fBSC.exe\fR.
.
.TP
\fB\-\-service\-monitor\fR
Causes the \fB\*(PN\fR service to be automatically restarted by the Windows
services manager if the service dies or exits for unexpected reasons.
.IP
When \fB\-\-service\fR is not specified, this option has no effect.
.SS "Logging Options"
.de IQ
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.  ns
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.IP "\fB\-v\fR[\fIspec\fR]
.IQ "\fB\-\-verbose=\fR[\fIspec\fR]
.
Sets logging levels.  Without any \fIspec\fR, sets the log level for
every module and facility to \fBdbg\fR.  Otherwise, \fIspec\fR is a
list of words separated by spaces or commas or colons, up to one from
each category below:
.
.RS
.IP \(bu
A valid module name, as displayed by the \fBvlog/list\fR command on
\fBovs\-appctl\fR(8), limits the log level change to the specified
module.
.
.IP \(bu
\fBsyslog\fR, \fBconsole\fR, or \fBfile\fR, to limit the log level
change to only to the system log, to the console, or to a file,
respectively.
.IP
On Windows platform, \fBsyslog\fR is accepted as a word and is only
useful along with the \fB\-\-syslog\-target\fR option (the word has no
effect otherwise).
.
.IP \(bu
\fBoff\fR, \fBemer\fR, \fBerr\fR, \fBwarn\fR, \fBinfo\fR, or
\fBdbg\fR, to control the log level.  Messages of the given severity
or higher will be logged, and messages of lower severity will be
filtered out.  \fBoff\fR filters out all messages.  See
\fBovs\-appctl\fR(8) for a definition of each log level.
.RE
.
.IP
Case is not significant within \fIspec\fR.
.IP
Regardless of the log levels set for \fBfile\fR, logging to a file
will not take place unless \fB\-\-log\-file\fR is also specified (see
below).
.IP
For compatibility with older versions of OVS, \fBany\fR is accepted as
a word but has no effect.
.
.IP "\fB\-v\fR"
.IQ "\fB\-\-verbose\fR"
Sets the maximum logging verbosity level, equivalent to
\fB\-\-verbose=dbg\fR.
.
.IP "\fB\-vPATTERN:\fIfacility\fB:\fIpattern\fR"
.IQ "\fB\-\-verbose=PATTERN:\fIfacility\fB:\fIpattern\fR"
Sets the log pattern for \fIfacility\fR to \fIpattern\fR.  Refer to
\fBovs\-appctl\fR(8) for a description of the valid syntax for \fIpattern\fR.
.
.TP
\fB\-\-log\-file\fR[\fB=\fIfile\fR]
Enables logging to a file.  If \fIfile\fR is specified, then it is
used as the exact name for the log file.  The default log file name
used if \fIfile\fR is omitted is \fB/var/log/openvswitch/\*(PN.log\fR.
.
.IP "\fB\-\-syslog\-target=\fIhost\fB:\fIport\fR"
Send syslog messages to UDP \fIport\fR on \fIhost\fR, in addition to
the system syslog.  The \fIhost\fR must be a numerical IP address, not
a hostname.
.SS "Public Key Infrastructure Options"
The options described below for configuring the SSL public key
infrastructure accept a special syntax for obtaining their
configuration from the database.  If any of these options is given
\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR as its argument, then the
actual file name is read from the specified \fIcolumn\fR in \fItable\fR
within the \fIdb\fR database.  The \fIcolumn\fR must have type
string or set of strings.  The first nonempty string in the table is taken
as the file name.  (This means that ordinarily there should be at most
one row in \fItable\fR.)
.de IQ
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.IP "\fB\-p\fR \fIprivkey.pem\fR"
.IQ "\fB\-\-private\-key=\fIprivkey.pem\fR"
Specifies a PEM file containing the private key used as \fB\*(PN\fR's
identity for outgoing SSL connections.
.
.IP "\fB\-c\fR \fIcert.pem\fR"
.IQ "\fB\-\-certificate=\fIcert.pem\fR"
Specifies a PEM file containing a certificate that certifies the
private key specified on \fB\-p\fR or \fB\-\-private\-key\fR to be
trustworthy.  The certificate must be signed by the certificate
authority (CA) that the peer in SSL connections will use to verify it.
.
.IP "\fB\-C\fR \fIcacert.pem\fR"
.IQ "\fB\-\-ca\-cert=\fIcacert.pem\fR"
Specifies a PEM file containing the CA certificate that \fB\*(PN\fR
should use to verify certificates presented to it by SSL peers.  (This
may be the same certificate that SSL peers use to verify the
certificate specified on \fB\-c\fR or \fB\-\-certificate\fR, or it may
be a different one, depending on the PKI design in use.)
.
.IP "\fB\-C none\fR"
.IQ "\fB\-\-ca\-cert=none\fR"
Disables verification of certificates presented by SSL peers.  This
introduces a security risk, because it means that certificates cannot
be verified to be those of known trusted hosts.
.IP "\fB\-\-bootstrap\-ca\-cert=\fIcacert.pem\fR"
When \fIcacert.pem\fR exists, this option has the same effect as
\fB\-C\fR or \fB\-\-ca\-cert\fR.  If it does not exist, then
\fB\*(PN\fR will attempt to obtain the CA certificate from the
SSL peer on its first SSL connection and save it to the named PEM
file.  If it is successful, it will immediately drop the connection
and reconnect, and from then on all SSL connections must be
authenticated by a certificate signed by the CA certificate thus
obtained.
.IP
\fBThis option exposes the SSL connection to a man-in-the-middle
attack obtaining the initial CA certificate\fR, but it may be useful
for bootstrapping.
.IP
This option is only useful if the SSL peer sends its CA certificate as
part of the SSL certificate chain.  The SSL protocol does not require
the server to send the CA certificate.
.IP
This option is mutually exclusive with \fB\-C\fR and
\fB\-\-ca\-cert\fR.
.SS "Other Options"
.IP "\fB\-\-unixctl=\fIsocket\fR"
Sets the name of the control socket on which \fB\*(PN\fR listens for
runtime management commands (see \fBRUNTIME MANAGEMENT COMMANDS\fR,
below).  If \fIsocket\fR does not begin with \fB/\fR, it is
interpreted as relative to \fB/var/run/openvswitch\fR.  If \fB\-\-unixctl\fR is
not used at all, the default socket is
\fB/var/run/openvswitch/\*(PN.\fIpid\fB.ctl\fR, where \fIpid\fR is \fB\*(PN\fR's
process ID.
.IP
On Windows, uses a kernel chosen TCP port on the localhost to listen
for runtime management commands.  The kernel chosen TCP port value is written
in a file whose absolute path is pointed by \fIsocket\fR. If \fB\-\-unixctl\fR
is not used at all, the file is created as \fB\*(PN.ctl\fR in the configured
\fIOVS_RUNDIR\fR directory.
.IP
Specifying \fBnone\fR for \fIsocket\fR disables the control socket
feature.
.de IQ
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..
.IP "\fB\-h\fR"
.IQ "\fB\-\-help\fR"
Prints a brief help message to the console.
.
.IP "\fB\-V\fR"
.IQ "\fB\-\-version\fR"
Prints version information to the console.
.SH "RUNTIME MANAGEMENT COMMANDS"
\fBovs\-appctl\fR(8) can send commands to a running
\fBovsdb\-server\fR process.  The currently supported commands are
described below.
.SS "OVSDB\-SERVER COMMANDS"
These commands are specific to \fBovsdb\-server\fR.
.IP "\fBexit\fR"
Causes \fBovsdb\-server\fR to gracefully terminate.
.IP "\fBovsdb\-server/compact\fR [\fIdb\fR]\&..."
Compacts each database \fIdb\fR in-place.  If no \fIdb\fR is
specified, compacts every database in-place.  Databases are also
automatically compacted occasionally.
.
.IP "\fBovsdb\-server/reconnect\fR"
Makes \fBovsdb\-server\fR drop all of the JSON\-RPC
connections to database clients and reconnect.
.IP
This command might be useful for debugging issues with database
clients.
.
.IP "\fBovsdb\-server/add\-remote \fIremote\fR"
Adds a remote, as if \fB\-\-remote=\fIremote\fR had been specified on
the \fBovsdb\-server\fR command line.  (If \fIremote\fR is already a
remote, this command succeeds without changing the configuration.)
.
.IP "\fBovsdb\-server/remove\-remote \fIremote\fR"
Removes the specified \fIremote\fR from the configuration, failing
with an error if \fIremote\fR is not configured as a remote.  This
command only works with remotes that were named on \fB\-\-remote\fR or
\fBovsdb\-server/add\-remote\fR, that is, it will not remove remotes
added indirectly because they were read from the database by
configuring a \fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR remote.
(You can remove a database source with \fBovsdb\-server/remove\-remote
\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR, but not individual
remotes found indirectly through the database.)
.
.IP "\fBovsdb\-server/list\-remotes"
Outputs a list of the currently configured remotes named on
\fB\-\-remote\fR or \fBovsdb\-server/add\-remote\fR, that is, it does
not list remotes added indirectly because they were read from the
database by configuring a
\fBdb:\fIdb\fB,\fItable\fB,\fIcolumn\fR remote.
.
.IP "\fBovsdb\-server/add\-db \fIdatabase\fR"
Adds the \fIdatabase\fR to the running \fBovsdb\-server\fR.  The database
file must already have been created and initialized using, for example,
\fBovsdb\-tool create\fR.
.
.IP "\fBovsdb\-server/remove\-db \fIdatabase\fR"
Removes \fIdatabase\fR from the running \fBovsdb\-server\fR.  \fIdatabase\fR
must be a database name as listed by \fBovsdb-server/list\-dbs\fR.
.IP
If a remote has been configured that points to the specified
\fIdatabase\fR (e.g. \fB\-\-remote=db:\fIdatabase\fB,\fR... on the
command line), then it will be disabled until another database with
the same name is added again (with \fBovsdb\-server/add\-db\fR).
.IP
Any public key infrastructure options specified through this database
(e.g. \fB\-\-private\-key=db:\fIdatabase,\fR... on the command line)
will be disabled until another database with the same name is added
again (with \fBovsdb\-server/add\-db\fR).
.
.IP "\fBovsdb\-server/list\-dbs"
Outputs a list of the currently configured databases added either through
the command line or through the \fBovsdb\-server/add\-db\fR command.
.
.de IQ
.  br
.  ns
.  IP "\\$1"
..
.SS "VLOG COMMANDS"
These commands manage \fB\*(PN\fR's logging settings.
.IP "\fBvlog/set\fR [\fIspec\fR]"
Sets logging levels.  Without any \fIspec\fR, sets the log level for
every module and facility to \fBdbg\fR.  Otherwise, \fIspec\fR is a
list of words separated by spaces or commas or colons, up to one from
each category below:
.
.RS
.IP \(bu
A valid module name, as displayed by the \fBvlog/list\fR command on
\fBovs\-appctl\fR(8), limits the log level change to the specified
module.
.
.IP \(bu
\fBsyslog\fR, \fBconsole\fR, or \fBfile\fR, to limit the log level
change to only to the system log, to the console, or to a file,
respectively.
.IP
On Windows platform, \fBsyslog\fR is accepted as a word and is only
useful along with the \fB\-\-syslog\-target\fR option (the word has no
effect otherwise).
.
.IP \(bu 
\fBoff\fR, \fBemer\fR, \fBerr\fR, \fBwarn\fR, \fBinfo\fR, or
\fBdbg\fR, to control the log level.  Messages of the given severity
or higher will be logged, and messages of lower severity will be
filtered out.  \fBoff\fR filters out all messages.  See
\fBovs\-appctl\fR(8) for a definition of each log level.
.RE
.
.IP
Case is not significant within \fIspec\fR.
.IP
Regardless of the log levels set for \fBfile\fR, logging to a file
will not take place unless \fB\*(PN\fR was invoked with the
\fB\-\-log\-file\fR option.
.IP
For compatibility with older versions of OVS, \fBany\fR is accepted as
a word but has no effect.
.RE
.IP "\fBvlog/set PATTERN:\fIfacility\fB:\fIpattern\fR"
Sets the log pattern for \fIfacility\fR to \fIpattern\fR.  Refer to
\fBovs\-appctl\fR(8) for a description of the valid syntax for \fIpattern\fR.
.
.IP "\fBvlog/list\fR"
Lists the supported logging modules and their current levels.
.
.IP "\fBvlog/reopen\fR"
Causes \fB\*(PN\fR to close and reopen its log file.  (This is useful
after rotating log files, to cause a new log file to be used.)
.IP
This has no effect unless \fB\*(PN\fR was invoked with the
\fB\-\-log\-file\fR option.
.
.IP "\fBvlog/disable\-rate\-limit \fR[\fImodule\fR]..."
.IQ "\fBvlog/enable\-rate\-limit \fR[\fImodule\fR]..."
By default, \fB\*(PN\fR limits the rate at which certain messages can
be logged.  When a message would appear more frequently than the
limit, it is suppressed.  This saves disk space, makes logs easier to
read, and speeds up execution, but occasionally troubleshooting
requires more detail.  Therefore, \fBvlog/disable\-rate\-limit\fR
allows rate limits to be disabled at the level of an individual log
module.  Specify one or more module names, as displayed by the
\fBvlog/list\fR command.  Specifying either no module names at all or
the keyword \fBany\fR disables rate limits for every log module.
.
.IP
The \fBvlog/enable\-rate\-limit\fR command, whose syntax is the same
as \fBvlog/disable\-rate\-limit\fR, can be used to re-enable a rate
limit that was previously disabled.
.SS "MEMORY COMMANDS"
These commands report memory usage.
.
.IP "\fBmemory/show\fR"
Displays some basic statistics about \fB\*(PN\fR's memory usage.
\fB\*(PN\fR also logs this information soon after startup and
periodically as its memory consumption grows.
.SS "COVERAGE COMMANDS"
These commands manage \fB\*(PN\fR's ``coverage counters,'' which count
the number of times particular events occur during a daemon's runtime.
In addition to these commands, \fB\*(PN\fR automatically logs coverage
counter values, at \fBINFO\fR level, when it detects that the daemon's
main loop takes unusually long to run.
.PP
Coverage counters are useful mainly for performance analysis and
debugging.
.IP "\fBcoverage/show\fR"
Displays the averaged per-second rates for the last few seconds, the
last minute and the last hour, and the total counts of all of the
coverage counters.
.SH "SPECIFICATIONS"
.
.PP
\fBovsdb\-server\fR implements the Open vSwitch Database (OVSDB)
protocol specified in RFC 7047, with the following clarifications:
.
.IP "3.1. JSON Usage"
RFC 4627 says that names within a JSON object should be unique.
The Open vSwitch JSON parser discards all but the last value
for a name that is specified more than once.
.
.IP "3.2. Schema Format"
RFC 7047 requires the "version" field in <database-schema>.  Current
versions of \fBovsdb\-server\fR allow it to be omitted (future
versions are likely to require it).
.
.IP "4. Wire Protocol"
The original OVSDB specifications included the following reason,
omitted from RFC 7047, to operate JSON-RPC directly over a stream
instead of over HTTP:
.
.RS
.IP \(bu
JSON-RPC is a peer-to-peer protocol, but HTTP is a client-server
protocol, which is a poor match.  Thus, JSON-RPC over HTTP requires
the client to periodically poll the server to receive server requests.
.IP \(bu
HTTP is more complicated than stream connections and doesn't provide
any corresponding advantage.
.IP \(bu
The JSON-RPC specification for HTTP transport is incomplete.
.RE
.
.IP "4.1.5. Monitor"
For backward compatibility, \fBovsdb\-server\fR currently permits a
single <monitor-request> to be used instead of an array; it is treated
as a single-element array.  Future versions of \fBovsdb\-server\fR
might remove this compatibility feature.
.IP
Because the <json-value> parameter is used to match subsequent update
notifications (see below) to the request, it must be unique among all
active monitors.  \fBovsdb\-server\fR rejects attempt to create two
monitors with the same identifier.
.
.IP "6. IANA Considerations"
\fBovsdb\-server\fR currently defaults to its historical port number
6632.  Future versions will adopt IANA-assigned port 6640 as default.

.SH "SEE ALSO"
.
.BR ovsdb\-tool (1).