ovsdb-server(1) Open vSwitch Manual ovsdb-server(1)
NAME
ovsdb-server - Open vSwitch database server
SYNOPSIS
ovsdb-server [database]... [--remote=remote]... [--run=command]
Daemon options:
[--pidfile[=pidfile]] [--overwrite-pidfile] [--detach]
[--no-chdir]
Service options:
[--service] [--service-monitor]
Logging options:
[-v[module[:destination[:level]]]]...
[--verbose[=module[:destination[:level]]]]...
[--log-file[=file]]
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]
Runtime management options:
--unixctl=socket
Common options:
[-h | --help] [-V | --version]
DESCRIPTION
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/etc/openvswitch/conf.db. The
database files must already have been created and initialized using,
for example, ovsdb-tool create.
OPTIONS
--remote=remote
Adds remote as a connection method used by ovsdb-server. remote
must take one of the following forms:
pssl:port[:ip]
Listen on the given SSL 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]. The --private-key, --certificate, and
--ca-cert options are mandatory when this form is used.
ptcp:port[:ip]
Listen on the given 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 ip may be specified to listen only for
connections to the given ip, either IPv4 or IPv6 address.
If ip is an IPv6 address, then wrap ip with square brack‐
ets, e.g.: ptcp:6640:[::1].
punix:file
On POSIX, listen on the Unix domain server socket named
file for a connection.
On Windows, listen on a kernel chosen TCP port on the
localhost. The kernel chosen TCP port value is written in
file.
ssl:ip:port
The specified SSL 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.
The --private-key, --certificate, and --ca-cert options
are mandatory when this form is used.
tcp:ip:port
Connect to the given TCP port on ip, where ip can be IPv4
or IPv6 address. If ip is an IPv6 address, then wrap ip
with square brackets, e.g.: tcp:[::1]:6640.
unix:file
On POSIX, connect to the Unix domain server socket named
file.
On Windows, connect to a localhost TCP port whose value
is written in file.
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 ta‐
ble to obtain a row. The following columns in the row,
if present and of the correct type, configure a connec‐
tion 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 config‐
ured.
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.
It is an error for column to have another type.
To connect or listen on multiple connection methods, use multi‐
ple --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 grace‐
fully. 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 indi‐
cating 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 /var/run/openvswitch.
If --pidfile is not specified, no pidfile is created.
--overwrite-pidfile
By default, when --pidfile is specified and the specified pid‐
file 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
Causes ovsdb-server to detach itself from the foreground session
and run as a background process. ovsdb-server detaches only
after it starts listening on all configured remotes.
--monitor
Creates an additional process to monitor the ovsdb-server dae‐
mon. If the daemon dies due to a signal that indicates a pro‐
gramming error (SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL, SIG‐
PIPE, 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 func‐
tions 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.
--user Causes ovsdb-server to run as a non root user specified in
"user:group", thus dropping all 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
interact with datapath, such as ovs-vswitchd, will be granted
two additional capabilities, namely CAP_NET_ADMIN and
CAP_NET_RAW.
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 com‐
mand 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 --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 --ver‐
bose=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 /var/log/open‐
vswitch/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 dae‐
mon. 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 possi‐
ble 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 pos‐
sible 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 sock‐
ets, but do not apply to UNIX domain sockets.
Public Key Infrastructure Options
The options described below for configuring the SSL public key infra‐
structure 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 certifi‐
cates 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 success‐
ful, it will immediately drop the connection and reconnect, and
from then on all SSL connections must be authenticated by a cer‐
tificate 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 use‐
ful for bootstrapping.
This option is only useful if the SSL peer sends its CA certifi‐
cate 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 cer‐
tificates 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.
Other Options
--unixctl=socket
Sets the name of the control socket on which ovsdb-server lis‐
tens for runtime management commands (see RUNTIME MANAGEMENT
COMMANDS, below). If socket does not begin with /, it is inter‐
preted as relative to /var/run/openvswitch. If --unixctl is not
used at all, the default socket is /var/run/open‐
vswitch/ovsdb-server.pid.ctl, where pid is ovsdb-server's
process ID.
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 socket. If --unixctl is not used at all, the file is created
as ovsdb-server.ctl in the configured OVS_RUNDIR directory.
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.
RUNTIME MANAGEMENT COMMANDS
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, com‐
pacts every database in-place. Databases are also automatically
compacted occasionally.
ovsdb-server/reconnect
Makes ovsdb-server drop all of the JSON-RPC connections to data‐
base 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,col‐
umn, 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 data‐
base 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.
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 com‐
mand 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/reopen
Causes ovsdb-server to close and reopen its log file. (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 mes‐
sages can be logged. When a message would appear more fre‐
quently 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 debug‐
ging.
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.
SPECIFICATIONS
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 gt; 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.
3.2. Schema Format
RFC 7047 requires the "version" field in gt;.
Current versions of ovsdb-server allow it to be omitted (future
versions are likely to require it).
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 incom‐
plete.
4.1.5. Monitor
For backward compatibility, ovsdb-server currently permits a
single gt; 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 gt; 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.
5.1. Notation
For gt;, RFC 7047 only allows the use of !=, ==,
includes, and excludes operators with set types. Open vSwitch
2.4 and later extend gt; to allow the use of =, >gt;>gt;=,
and >gt;>gt; 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.
BUGS
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).
SEE ALSO
ovsdb-tool(1).
Open vSwitch 2.4.90 ovsdb-server(1)