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NAME | SYNOPSIS | DESCRIPTION | ACTIVE and BACKUP | OPTIONS | RUNTIME MANAGEMENT COMMANDS | SPECIFICATIONS | BUGS | SEE ALSO | COLOPHON |
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ovsdb-server(1) Open vSwitch Manual ovsdb-server(1)
ovsdb-server - Open vSwitch database server
ovsdb-server [database]... [--remote=remote]... [--run=command]
Daemon options:
[--pidfile[=pidfile]] [--overwrite-pidfile] [--detach]
[--no-chdir] [--no-self-confinement]
Service options:
[--service] [--service-monitor]
Logging options:
[-v[module[:destination[:level]]]]...
[--verbose[=module[:destination[:level]]]]...
[--log-file[=file]]
Syncing options:
[--sync-from=server]
Public key infrastructure options:
[--private-key=privkey.pem]
[--certificate=cert.pem]
[--ca-cert=cacert.pem]
[--bootstrap-ca-cert=cacert.pem]
[--peer-ca-cert=peer-cacert.pem]
SSL connection options:
[--ssl-protocols=protocols]
[--ssl-ciphers=ciphers]
Runtime management options:
--unixctl=socket
Common options:
[-h | --help] [-V | --version]
The ovsdb-server 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.
Each OVSDB file may be specified on the command line as database. If
none is specified, the default is /usr/local/etc/openvswitch/conf.db.
The database files must already have been created and initialized
using, for example, ovsdb-tool create.
ovsdb-server runs either as a backup server, or as an active server.
When ovsdb-server is running as a backup server, all transactions
that can modify the database content, including the lock commands are
rejected. Active server, on the other hand, accepts all ovsdb server
transactions. When ovsdb-server role changes, all existing client
connection are reset, requiring clients to reconnect to the server.
By default, ovsdb-server runs as an active server, except when the
--sync-from=server command line option is specified and without the
--active option. During runtime, ovsdb-server role can be switch by
using appctl commands.
ovsdb-server/connect-active-ovsdb-server switches ovsdb-server into a
backup server, Conversely, ovsdb-
server/disconnect-active-ovsdb-server switches server into an active
one.
--remote=remote
Adds remote as a connection method used by ovsdb-server.
remote must take one of the following forms:
pssl:port[:ip]
ptcp:port[:ip]
Listen on the given SSL or TCP port 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 ip limits connections
to those from the given ip, either IPv4 or IPv6
address. If ip is an IPv6 address, then wrap ip with
square brackets, e.g.: pssl:6640:[::1]. On Linux, use
%device to designate a scope for IPv6 link-level
addresses, e.g. pssl:6653:[fe80::1234%eth0]. For pssl,
the --private-key, --certificate, and --ca-cert options
are mandatory.
punix:file
On POSIX, listen on the Unix domain server socket named
file for a connection.
On Windows, listen on a local named pipe. A file is
created in the path file to mimic the behavior of a
Unix domain socket.
ssl:ip:port
tcp:ip:port
The given SSL or plain TCP port on the host at the
given ip, which must be expressed as an IP address (not
a DNS name) in IPv4 or IPv6 address format. If ip is
an IPv6 address, then wrap ip with square brackets,
e.g.: ssl:[::1]:6640. On Linux, use %device to
designate a scope for IPv6 link-level addresses, e.g.
ssl:[fe80::1234%eth0]:6653. For ssl, the
--private-key, --certificate, and --ca-cert options are
mandatory.
unix:file
On POSIX, connect to the Unix domain server socket
named file.
On Windows, connect to a local named pipe that is
represented by a file created in the path file to mimic
the behavior of a Unix domain socket.
db:db,table,column
Reads additional connection methods from column in all
of the rows in table within db. As the contents of
column changes, ovsdb-server also adds and drops
connection methods accordingly.
If column'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.
If column'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.
target (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.
max_backoff (integer)
Maximum number of milliseconds to wait between
connection attempts.
inactivity_probe (integer)
Maximum number of milliseconds of idle time on
connection to client before sending an
inactivity probe message.
read_only (boolean)
If true, only read-only transactions are allowed
on this connection.
It is an error for column to have another type.
To connect or listen on multiple connection methods, use
multiple --remote options.
--run=command]
Ordinarily ovsdb-server runs forever, or until it is told to
exit (see RUNTIME MANAGEMENT COMMANDS below). With this
option, ovsdb-server instead starts a shell subprocess running
command. When the subprocess terminates, ovsdb-server also
exits gracefully. If the subprocess exits normally with exit
code 0, then ovsdb-server exits with exit code 0 also;
otherwise, it exits with exit code 1.
This option can be useful where a database server is needed
only to run a single command, e.g.: ovsdb-server
--remote=punix:socket --run='ovsdb-client dump unix:socket
Open_vSwitch'
This option is not supported on Windows platform.
Daemon Options
The following options are valid on POSIX based platforms.
--pidfile[=pidfile]
Causes a file (by default, ovsdb-server.pid) to be created
indicating the PID of the running process. If the pidfile
argument is not specified, or if it does not begin with /,
then it is created in /usr/local/var/run/openvswitch.
If --pidfile is not specified, no pidfile is created.
--overwrite-pidfile
By default, when --pidfile is specified and the specified
pidfile already exists and is locked by a running process,
ovsdb-server refuses to start. Specify --overwrite-pidfile to
cause it to instead overwrite the pidfile.
When --pidfile is not specified, this option has no effect.
--detach
Runs ovsdb-server as a background process. The process forks,
and in the child it starts a new session, closes the standard
file descriptors (which has the side effect of disabling
logging to the console), and changes its current directory to
the root (unless --no-chdir is specified). After the child
completes its initialization, the parent exits. ovsdb-server
detaches only after it starts listening on all configured
remotes.
--monitor
Creates an additional process to monitor the ovsdb-server
daemon. If the daemon dies due to a signal that indicates a
programming error (SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL,
SIGPIPE, SIGSEGV, SIGXCPU, or SIGXFSZ) then the monitor
process starts a new copy of it. If the daemon dies or exits
for another reason, the monitor process exits.
This option is normally used with --detach, but it also
functions without it.
--no-chdir
By default, when --detach is specified, ovsdb-server changes
its current working directory to the root directory after it
detaches. Otherwise, invoking ovsdb-server from a carelessly
chosen directory would prevent the administrator from
unmounting the file system that holds that directory.
Specifying --no-chdir suppresses this behavior, preventing
ovsdb-server 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.
This option has no effect when --detach is not specified.
--no-self-confinement
By default daemon will try to self-confine itself to work with
files under well-know, at build-time whitelisted directories.
It is better to stick with this default behavior and not to
use this flag unless some other Access Control is used to
confine daemon. Note that in contrast to other access control
implementations that are typically enforced from kernel-space
(e.g. DAC or MAC), self-confinement is imposed from the user-
space daemon itself and hence should not be considered as a
full confinement strategy, but instead should be viewed as an
additional layer of security.
--user Causes ovsdb-server to run as a different user specified in
"user:group", thus dropping most of the root privileges. Short
forms "user" and ":group" are also allowed, with current user
or group are assumed respectively. Only daemons started by the
root user accepts this argument.
On Linux, daemons will be granted CAP_IPC_LOCK and
CAP_NET_BIND_SERVICES before dropping root privileges. Daemons
that interact with a datapath, such as ovs-vswitchd, will be
granted two additional capabilities, namely CAP_NET_ADMIN and
CAP_NET_RAW. The capability change will apply even if new user
is "root".
On Windows, this option is not currently supported. For
security reasons, specifying this option will cause the daemon
process not to start.
Service Options
The following options are valid only on Windows platform.
--service
Causes ovsdb-server to run as a service in the background. The
service should already have been created through external
tools like SC.exe.
--service-monitor
Causes the ovsdb-server service to be automatically restarted
by the Windows services manager if the service dies or exits
for unexpected reasons.
When --service is not specified, this option has no effect.
Logging Options
-v[spec]
--verbose=[spec]
Sets logging levels. Without any spec, sets the log level for
every module and destination to dbg. Otherwise, spec is a
list of words separated by spaces or commas or colons, up to
one from each category below:
· A valid module name, as displayed by the vlog/list
command on ovs-appctl(8), limits the log level change
to the specified module.
· syslog, console, or file, to limit the log level change
to only to the system log, to the console, or to a
file, respectively. (If --detach is specified,
ovsdb-server closes its standard file descriptors, so
logging to the console will have no effect.)
On Windows platform, syslog is accepted as a word and
is only useful along with the --syslog-target option
(the word has no effect otherwise).
· off, emer, err, warn, info, or dbg, to control the log
level. Messages of the given severity or higher will
be logged, and messages of lower severity will be
filtered out. off filters out all messages. See
ovs-appctl(8) for a definition of each log level.
Case is not significant within spec.
Regardless of the log levels set for file, logging to a file
will not take place unless --log-file is also specified (see
below).
For compatibility with older versions of OVS, any is accepted
as a word but has no effect.
-v
--verbose
Sets the maximum logging verbosity level, equivalent to
--verbose=dbg.
-vPATTERN:destination:pattern
--verbose=PATTERN:destination:pattern
Sets the log pattern for destination to pattern. Refer to
ovs-appctl(8) for a description of the valid syntax for
pattern.
-vFACILITY:facility
--verbose=FACILITY:facility
Sets the RFC5424 facility of the log message. facility can be
one of kern, user, mail, daemon, auth, syslog, lpr, news,
uucp, clock, ftp, ntp, audit, alert, clock2, local0, local1,
local2, local3, local4, local5, local6 or local7. If this
option is not specified, daemon is used as the default for the
local system syslog and local0 is used while sending a message
to the target provided via the --syslog-target option.
--log-file[=file]
Enables logging to a file. If file is specified, then it is
used as the exact name for the log file. The default log file
name used if file is omitted is
/usr/local/var/log/openvswitch/ovsdb-server.log.
--syslog-target=host:port
Send syslog messages to UDP port on host, in addition to the
system syslog. The host must be a numerical IP address, not a
hostname.
--syslog-method=method
Specify method how syslog messages should be sent to syslog
daemon. Following forms are supported:
· libc, use libc syslog() function. This is the default
behavior. Downside of using this options is that libc
adds fixed prefix to every message before it is
actually sent to the syslog daemon over /dev/log UNIX
domain socket.
· unix:file, use UNIX domain socket directly. It is
possible to specify arbitrary message format with this
option. However, rsyslogd 8.9 and older versions use
hard coded parser function anyway that limits UNIX
domain socket use. If you want to use arbitrary
message format with older rsyslogd versions, then use
UDP socket to localhost IP address instead.
· udp:ip:port, use UDP socket. With this method it is
possible to use arbitrary message format also with
older rsyslogd. When sending syslog messages over UDP
socket extra precaution needs to be taken into account,
for example, syslog daemon needs to be configured to
listen on the specified UDP port, accidental iptables
rules could be interfering with local syslog traffic
and there are some security considerations that apply
to UDP sockets, but do not apply to UNIX domain
sockets.
Syncing Options
The following options allow ovsdb-server to synchronize its
databases with another running ovsdb-server.
--sync-from=server
Sets up ovsdb-server to synchronize its databases with the
databases in server, which must be an active connection method
in one of the forms documented in ovsdb-client(1). Every
transaction committed by server will be replicated to
ovsdb-server. This option makes ovsdb-server start as a
backup server; add --active to make it start as an active
server.
--sync-exclude-tables=db:table[,db:table]...
Causes the specified tables to be excluded from replication.
--active
By default, --sync-from makes ovsdb-server start up as a
backup for server. With --active, however, ovsdb-server
starts as an active server. Use this option to allow the
syncing options to be specified using command line options,
yet start the server, as the default, active server. To
switch the running server to backup mode, use ovs-appctl(1) to
execute the ovsdb-server/connect-active-ovsdb-server command.
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
db:db,table,column as its argument, then the actual file name is read
from the specified column in table within the db database. The
column 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 table.)
-p privkey.pem
--private-key=privkey.pem
Specifies a PEM file containing the private key used as
ovsdb-server's identity for outgoing SSL connections.
-c cert.pem
--certificate=cert.pem
Specifies a PEM file containing a certificate that certifies
the private key specified on -p or --private-key to be
trustworthy. The certificate must be signed by the
certificate authority (CA) that the peer in SSL connections
will use to verify it.
-C cacert.pem
--ca-cert=cacert.pem
Specifies a PEM file containing the CA certificate that
ovsdb-server 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 -c or
--certificate, or it may be a different one, depending on the
PKI design in use.)
-C none
--ca-cert=none
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.
--bootstrap-ca-cert=cacert.pem
When cacert.pem exists, this option has the same effect as -C
or --ca-cert. If it does not exist, then ovsdb-server 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.
This option exposes the SSL connection to a man-in-the-middle
attack obtaining the initial CA certificate, but it may be
useful for bootstrapping.
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.
This option is mutually exclusive with -C and --ca-cert.
--peer-ca-cert=peer-cacert.pem
Specifies a PEM file that contains one or more additional
certificates to send to SSL peers. peer-cacert.pem should be
the CA certificate used to sign ovsdb-server's own
certificate, that is, the certificate specified on -c or
--certificate. If ovsdb-server's certificate is self-signed,
then --certificate and --peer-ca-cert should specify the same
file.
This option is not useful in normal operation, because the SSL
peer must already have the CA certificate for the peer to have
any confidence in ovsdb-server's identity. However, this
offers a way for a new installation to bootstrap the CA
certificate on its first SSL connection.
SSL Connection Options
--ssl-protocols=protocols
Specifies, in a comma- or space-delimited list, the SSL
protocols ovsdb-server will enable for SSL connections.
Supported protocols include TLSv1, TLSv1.1, and TLSv1.2.
Regardless of order, the highest protocol supported by both
sides will be chosen when making the connection. The default
when this option is omitted is TLSv1,TLSv1.1,TLSv1.2.
--ssl-ciphers=ciphers
Specifies, in OpenSSL cipher string format, the ciphers
ovsdb-server will support for SSL connections. The default
when this option is omitted is HIGH:!aNULL:!MD5.
Other Options
--unixctl=socket
Sets the name of the control socket on which ovsdb-server
listens for runtime management commands (see RUNTIME
MANAGEMENT COMMANDS, below). If socket does not begin with /,
it is interpreted as relative to
/usr/local/var/run/openvswitch. If --unixctl is not used at
all, the default socket is
/usr/local/var/run/openvswitch/ovsdb-server.pid.ctl, where pid
is ovsdb-server's process ID.
On Windows a local named pipe is used to listen for runtime
management commands. A file is created in the absolute path
as pointed by socket or if --unixctl is not used at all, a
file is created as ovsdb-server.ctl in the configured
OVS_RUNDIR directory. The file exists just to mimic the
behavior of a Unix domain socket.
Specifying none for socket disables the control socket
feature.
-h
--help Prints a brief help message to the console.
-V
--version
Prints version information to the console.
ovs-appctl(8) can send commands to a running ovsdb-server process.
The currently supported commands are described below.
OVSDB-SERVER COMMANDS
These commands are specific to ovsdb-server.
exit Causes ovsdb-server to gracefully terminate.
ovsdb-server/compact [db]...
Compacts each database db in-place. If no db is specified,
compacts every database in-place. A database is also
compacted automatically when a transaction is logged if it is
over 4 times as large as its previous compacted size (and at
least 10 MB), but not before 100 commits have been added or 10
minutes have elapsed since the last compaction.
ovsdb-server/reconnect
Makes ovsdb-server drop all of the JSON-RPC connections to
database clients and reconnect.
This command might be useful for debugging issues with
database clients.
ovsdb-server/add-remote remote
Adds a remote, as if --remote=remote had been specified on the
ovsdb-server command line. (If remote is already a remote,
this command succeeds without changing the configuration.)
ovsdb-server/remove-remote remote
Removes the specified remote from the configuration, failing
with an error if remote is not configured as a remote. This
command only works with remotes that were named on --remote or
ovsdb-server/add-remote, that is, it will not remove remotes
added indirectly because they were read from the database by
configuring a db:db,table,column remote. (You can remove a
database source with ovsdb-server/remove-remote
db:db,table,column, but not individual remotes found
indirectly through the database.)
ovsdb-server/list-remotes
Outputs a list of the currently configured remotes named on
--remote or ovsdb-server/add-remote, that is, it does not list
remotes added indirectly because they were read from the
database by configuring a db:db,table,column remote.
ovsdb-server/add-db database
Adds the database to the running ovsdb-server. The database
file must already have been created and initialized using, for
example, ovsdb-tool create.
ovsdb-server/remove-db database
Removes database from the running ovsdb-server. database must
be a database name as listed by ovsdb-server/list-dbs.
If a remote has been configured that points to the specified
database (e.g. --remote=db:database,... on the command line),
then it will be disabled until another database with the same
name is added again (with ovsdb-server/add-db).
Any public key infrastructure options specified through this
database (e.g. --private-key=db:database,... on the command
line) will be disabled until another database with the same
name is added again (with ovsdb-server/add-db).
ovsdb-server/list-dbs
Outputs a list of the currently configured databases added
either through the command line or through the
ovsdb-server/add-db command.
ovsdb-server/set-active-ovsdb-server server
Sets the active server from which ovsdb-server connects
through ovsdb-server/connect-active-ovsdb-server.
ovsdb-server/get-active-ovsdb-server
Gets the active server from which ovsdb-server is currently
synchronizing its databases.
ovsdb-server/connect-active-ovsdb-server
Causes ovsdb-server to synchronize its databases with the
server specified by ovsdb-server/set-active-ovsdb-server.
ovsdb-server/disconnect-active-ovsdb-server
Causes ovsdb-server to stop synchronizing its databases
with a active server.
ovsdb-server/set-sync-exclude-tables db:table[,db:table]...
Sets the table whitin db that will be excluded from
synchronization.
ovsdb-server/get-sync-exclude-tables
Gets the tables that are currently excluded from
synchronization.
ovsdb-server/sync-status
Prints a summary of replication run time information. The
state information is always provided, indicating whether the
server is running in the active or the backup mode. When
running in backup mode, replication connection status, which
can be either connecting, replicating or error, are shown.
When the connection is in replicating state, further output
shows the list of databases currently replicating, and the
tables that are excluded.
VLOG COMMANDS
These commands manage ovsdb-server's logging settings.
vlog/set [spec]
Sets logging levels. Without any spec, sets the log level for
every module and destination to dbg. Otherwise, spec is a
list of words separated by spaces or commas or colons, up to
one from each category below:
· A valid module name, as displayed by the vlog/list
command on ovs-appctl(8), limits the log level change
to the specified module.
· syslog, console, or file, to limit the log level change
to only to the system log, to the console, or to a
file, respectively.
On Windows platform, syslog is accepted as a word and
is only useful along with the --syslog-target option
(the word has no effect otherwise).
· off, emer, err, warn, info, or dbg, to control the log
level. Messages of the given severity or higher will
be logged, and messages of lower severity will be
filtered out. off filters out all messages. See
ovs-appctl(8) for a definition of each log level.
Case is not significant within spec.
Regardless of the log levels set for file, logging to a file
will not take place unless ovsdb-server was invoked with the
--log-file option.
For compatibility with older versions of OVS, any is accepted
as a word but has no effect.
vlog/set PATTERN:destination:pattern
Sets the log pattern for destination to pattern. Refer to
ovs-appctl(8) for a description of the valid syntax for
pattern.
vlog/list
Lists the supported logging modules and their current levels.
vlog/list-pattern
Lists logging patterns used for each destination.
vlog/close
Causes ovsdb-server to close its log file, if it is open.
(Use vlog/reopen to reopen it later.)
vlog/reopen
Causes ovsdb-server to close its log file, if it is open, and
then reopen it. (This is useful after rotating log files, to
cause a new log file to be used.)
This has no effect unless ovsdb-server was invoked with the
--log-file option.
vlog/disable-rate-limit [module]...
vlog/enable-rate-limit [module]...
By default, ovsdb-server 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,
vlog/disable-rate-limit allows rate limits to be disabled at
the level of an individual log module. Specify one or more
module names, as displayed by the vlog/list command.
Specifying either no module names at all or the keyword any
disables rate limits for every log module.
The vlog/enable-rate-limit command, whose syntax is the same
as vlog/disable-rate-limit, can be used to re-enable a rate
limit that was previously disabled.
MEMORY COMMANDS
These commands report memory usage.
memory/show
Displays some basic statistics about ovsdb-server's memory
usage. ovsdb-server also logs this information soon after
startup and periodically as its memory consumption grows.
COVERAGE COMMANDS
These commands manage ovsdb-server's ``coverage counters,'' which
count the number of times particular events occur during a daemon's
runtime. In addition to these commands, ovsdb-server automatically
logs coverage counter values, at INFO level, when it detects that the
daemon's main loop takes unusually long to run.
Coverage counters are useful mainly for performance analysis and
debugging.
coverage/show
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.
ovsdb-server implements the Open vSwitch Database (OVSDB) protocol
specified in RFC 7047, with the following clarifications:
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.
The definition of <error> allows for implementation
extensions. Currently ovsdb-server uses the following
additional "error" strings which might change in later
releases):
syntax error or unknown column
The request could not be parsed as an OVSDB request.
An additional "syntax" member, whose value is a string
that contains JSON, may narrow down the particular
syntax that could not be parsed.
internal error
The request triggered a bug in ovsdb-server.
ovsdb error
A map or set contains a duplicate key.
permission error
The request was denied by the role-based access control
extension, introduced in version 2.8.
3.2. Schema Format
RFC 7047 requires the "version" field in <database-schema>.
Current versions of ovsdb-server allow it to be omitted
(future versions are likely to require it).
RFC 7047 allows columns that contain weak references to be
immutable. This raises the issue of the behavior of the weak
reference when the rows that it references are deleted. Since
version 2.6, ovsdb-server forces columns that contain weak
references to be mutable.
Since version 2.8, the table name RBAC_Role is used internally
by the role-based access control extension to ovsdb-server and
should not be used for purposes other than defining mappings
of role names to table access permissions. This table has one
row per role name and the following columns:
name The role name.
permissions
A map of table name to a reference to a row in a
separate permission table.
The separate RBAC permission table has one row per access
control configuration and the following columns:
name The name of the table to which the row applies.
authorization
The set of column names and column:key pairs to be
compared with the client ID in order to determine the
authorization status of the requested operation.
insert_delete
A boolean value, true if authorized insertions and
authorized are allowed, false if no insertions or
deletions are allowed.
update The set of columns and column:key pairs for which
authorized update and mutate operations should be
permitted.
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:
· 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.
· HTTP is more complicated than stream connections and
doesn't provide any corresponding advantage.
· The JSON-RPC specification for HTTP transport is
incomplete.
4.1.3. Transact
Since version 2.8, role-based access controls can be applied
to operations within a transaction that would modify the
contents of the database (these operations include row insert,
row delete, column update, and column mutate). Role-based
access controls are applied when the database schema contains
a table with the name "RBAC_Role" and the connection on which
the transaction request was received has an associated role
name (from the "role" column in the remote connection table).
When role-based access controls are enabled, transactions that
are otherwise well-formed may be rejected depending on the
client's role, ID, and the contents of the RBAC_Role table and
associated permissions table.
4.1.5. Monitor
For backward compatibility, ovsdb-server currently permits a
single <monitor-request> to be used instead of an array; it is
treated as a single-element array. Future versions of
ovsdb-server might remove this compatibility feature.
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. ovsdb-server rejects
attempt to create two monitors with the same identifier.
4.1.12. Monitor_cond
A new monitor method added in Open vSwitch version 2.6. The
monitor_cond request enables a client to replicate subsets of
tables within an OVSDB database by requesting notifications of
changes to rows matching one of the conditions specified in
"where" by receiving the specified contents of these rows when
table updates occur. Monitor_cond also allows a more efficient
update notifications by receiving table-updates2 notifications
(described below).
The monitor method described in Section 4.1.5 also applies to
monitor_cond, with the following exceptions:
· RPC request method becomes "monitor_cond".
· Reply result follows <table-updates2>, described in
Section 4.1.14.
· Subsequent changes are sent to the client using the
"update2" monitor notification, described in Section
4.1.14
· Update notifications are being sent only for rows
matching [<condition>*].
The request object has the following members:
"method": "monitor_cond"
"params": [<db-name>, <json-value>, <monitor-cond-requests>]
"id": <nonnull-json-value>
The <json-value> parameter is used to match subsequent update
notifications (see below) to this request. The <monitor-cond-
requests> object maps the name of the table to an array of
<monitor-cond-request>.
Each <monitor-cond-request> is an object with the following
members:
"columns": [<column>*] optional
"where": [<condition>*] optional
"select": <monitor-select> optional
The "columns", if present, define the columns within the table
to be monitored that match conditions. If not present all
columns are being monitored.
The "where" if present is a JSON array of <condition> and
boolean values. If not present or condition is an empty array,
implicit True will be considered and updates on all rows will
be sent.
<monitor-select> is an object with the following members:
"initial": <boolean> optional
"insert": <boolean> optional
"delete": <boolean> optional
"modify": <boolean> optional
The contents of this object specify how the columns or table
are to be monitored as explained in more detail below.
The response object has the following members:
"result": <table-updates2>
"error": null
"id": same "id" as request
The <table-updates2> object is described in detail in Section
4.1.14. It contains the contents of the tables for which
"initial" rows are selected. If no tables initial contents
are requested, then "result" is an empty object.
Subsequently, when changes to a specified table that match one
of the conditions in monitor-cond-request are committed, the
changes are automatically sent to the client using the
"update2" monitor notification (see Section 4.1.14). This
monitoring persists until the JSON-RPC session terminates or
until the client sends a "monitor_cancel" JSON-RPC request.
Each <monitor-cond-request> specifies one or more conditions
and the manner in which the rows that match the conditions are
to be monitored. The circumstances in which an "update"
notification is sent for a row within the table are determined
by <monitor-select>:
· If "initial" is omitted or true, every row in the
original table that matches one of the conditions is
sent as part of the response to the "monitor_cond"
request.
· If "insert" is omitted or true, "update" notifications
are sent for rows newly inserted into the table that
match conditions or for rows modified in the table so
that their old version does not match the condition and
new version does.
· If "delete" is omitted or true, "update" notifications
are sent for rows deleted from the table that match
conditions or for rows modified in the table so that
their old version does match the conditions and new
version does not.
· If "modify" is omitted or true, "update" notifications
are sent whenever a row in the table that matches
conditions in both old and new version is modified.
Both monitor and monitor_cond sessions can exist concurrently.
However, monitor and monitor_cond shares the same <json-value>
parameter space; it must be unique among all monitor and
monitor_cond sessions.
4.1.13. Monitor_cond_change
The "monitor_cond_change" request enables a client to change
an existing "monitor_cond" replication of the database by
specifying a new condition and columns for each replicated
table. Currently changing the columns set is not supported.
The request object has the following members:
"method": "monitor_cond_change"
"params": [<json-value>, <json-value>, <monitor-cond-update-requests>]
"id": <nonnull-json-value>
The <json-value> parameter should have a value of an existing
conditional monitoring session from this client. The second
<json-value> in params array is the requested value for this
session. This value is valid only after "monitor_cond_change"
is committed. A user can use these values to distinguish
between update messages before conditions update and after.
The <monitor-cond-update-requests> object maps the name of the
table to an array of <monitor-cond-update-request>.
Each <monitor-cond-update-request> is an object with the
following members:
"columns": [<column>*] optional
"where": [<condition>*] optional
The "columns" specify a new array of columns to be monitored
(Currently unsupported).
The "where" specify a new array of conditions to be applied to
this monitoring session.
The response object has the following members:
"result": null
"error": null
"id": same "id" as request
Subsequent <table-updates2> notifications are described in
detail in Section 4.1.14 in the RFC. If insert contents are
requested by original monitor_cond request, <table-updates2>
will contain rows that match the new condition and do not
match the old condition. If deleted contents are requested by
origin monitor request, <table-updates2> will contain any
matched rows by old condition and not matched by the new
condition.
Changes according to the new conditions are automatically sent
to the client using the "update2" monitor notification. An
update, if any, as a result of a condition change, will be
sent to the client before the reply to the
"monitor_cond_change" request.
4.1.14. Update2 notification
The "update2" notification is sent by the server to the client
to report changes in tables that are being monitored following
a "monitor_cond" request as described above. The notification
has the following members:
"method": "update2"
"params": [<json-value>, <table-updates2>]
"id": null
The <json-value> in "params" is the same as the value passed
as the <json-value> in "params" for the corresponding
"monitor" request. <table-updates2> is an object that maps
from a table name to a <table-update2>. A <table-update2> is
an object that maps from row's UUID to a <row-update2> object.
A <row-update2> is an object with one of the following
members:
"initial": <row>
present for "initial" updates
"insert": <row>
present for "insert" updates
"delete": <row>
present for "delete" updates
"modify": <row>
present for "modify" updates
The format of <row> is described in Section 5.1.
<row> is always a null object for a "delete" update. In
"initial" and "insert" updates, <row> omits columns whose
values equal the default value of the column type.
For a "modify" update, <row> contains only the columns that
are modified. <row> stores the difference between the old and
new value for those columns, as described below.
For columns with single value, the difference is the value of
the new column.
The difference between two sets are all elements that only
belong to one of the sets.
The difference between two maps are all key-value pairs whose
keys appears in only one of the maps, plus the key-value pairs
whose keys appear in both maps but with different values. For
the latter elements, <row> includes the value from the new
column.
Initial views of rows are not presented in update2
notifications, but in the response object to the monitor_cond
request. The formatting of the <table-updates2> object,
however, is the same in either case.
4.1.15. Get Server ID
A new RPC method added in Open vSwitch version 2.7. The
request contains the following members:
"method": "get_server_id"
"params": null
"id": <nonnull-json-value>
The response object contains the following members:
"result": "<server_id>"
"error": null
"id": same "id" as request
<server_id> is JSON string that contains a UUID that uniquely
identifies the running OVSDB server process. A fresh UUID is
generated when the process restarts.
5.1. Notation
For <condition>, RFC 7047 only allows the use of !=, ==,
includes, and excludes operators with set types. Open vSwitch
2.4 and later extend <condition> to allow the use of <, <=,
>=, and > operators with columns with type ``set of 0 or 1
integer'' and ``set of 0 or 1 real''. These conditions
evaluate to false when the column is empty, and otherwise as
described in RFC 7047 for integer and real types.
<condition> is specified in Section 5.1 in the RFC with the
following change: A condition can be either a 3-element JSON
array as described in the RFC or a boolean value. In case of
an empty array an implicit true boolean value will be
considered.
5.2.6. Wait
5.2.7. Commit
5.2.9. Comment
RFC 7047 says that the wait, commit, and comment operations
have no corresponding result object. This is not true.
Instead, when such an operation is successful, it yields a
result object with no members.
In Open vSwitch before version 2.4, when ovsdb-server sent JSON-RPC
error responses to some requests, it incorrectly formulated them with
the result and error swapped, so that the response appeared to
indicate success (with a nonsensical result) rather than an error.
The requests that suffered from this problem were:
transact
get_schema
Only if the request names a nonexistent database.
monitor
lock
unlock In all error cases.
Of these cases, the only error that a well-written application is
likely to encounter in practice is monitor of tables or columns that
do not exist, in an situation where the application has been upgraded
but the old database schema is still temporarily in use. To handle
this situation gracefully, we recommend that clients should treat a
monitor response with a result that contains an error key-value pair
as an error (assuming that the database being monitored does not
contain a table named error).
ovsdb-tool(1).
This page is part of the Open vSwitch (a distributed virtual
multilayer switch) project. Information about the project can be
found at ⟨http://openvswitch.org/⟩. If you have a bug report for
this manual page, send it to bugs@openvswitch.org. This page was
obtained from the project's upstream Git repository
⟨https://github.com/openvswitch/ovs.git⟩ on 2018-02-02. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2018-02-01.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
Open vSwitch 2.8.90 ovsdb-server(1)
Pages that refer to this page: ovsdb-client(1), ovsdb-tool(1), ovn-architecture(7), ovs-vsctl(8), ovs-vswitchd(8), vtep-ctl(8)
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