ovsdb-server - Open vSwitch database server
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. For an
introduction to OVSDB and its implementation in Open vSwitch, see
ovsdb(7).
Each OVSDB file may be specified on the command line as
database. If none is specified, the default is
/etc/openvswitch/conf.db. The database files must already have been
created and initialized using, for example, ovsdb-tool's
create, create-cluster, or join-cluster command.
This OVSDB implementation supports standalone, active-backup, and
clustered database service models, as well as database replication. See the
Service Models section of ovsdb(7) for more information.
For clustered databases, when the --detach option is used,
ovsdb-server detaches without waiting for the server to successfully
join a cluster (if the database file is freshly created with ovsdb-tool
join-cluster) or connect to a cluster that it has already joined. Use
ovsdb-client wait (see ovsdb-client(1)) to wait until the
server has successfully joined and connected to a cluster.
In addition to user-specified databases, ovsdb-server
version 2.9 and later also always hosts a built-in database named
_Server. Please see ovsdb-server(5) for documentation on this
database's schema.
- --remote=remote
- Adds remote as a connection method used by ovsdb-server. The
remote may be an OVSDB active or passive connection method, e.g.
pssl:6640, as described in ovsdb(7). The following
additional form is also supported:
- 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.
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 /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. At this point, all standalone and active-backup
databases are ready for use. Clustered databases only become ready for use
after they finish joining their clusters (which could have already
happened in previous runs of ovsdb-server).
- --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 three additional
capabilities, namely CAP_NET_ADMIN, CAP_NET_BROADCAST and CAP_NET_RAW. The
capability change will apply even if the 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.
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.
- -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
/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.
These options support the ovsdb-server active-backup
service model and database replication. These options apply only to
databases in the format used for standalone and active-backup databases,
which is the database format created by ovsdb-tool create. By
default, when it serves a database in this format, ovsdb-server runs
as a standalone server. These options can configure it for active-backup
use:
- Use --sync-from=server to start the server in the backup
role, replicating data from server. When ovsdb-server is
running as a backup server, it rejects all transactions that can modify
the database content, including lock commands. The same form can be used
to configure the local database as a replica of server.
- Use --sync-from=server --active to start the server
in the active role, but prepared to switch to the backup role in which it
would replicate data from server. When ovsdb-server runs in
active mode, it allows all transactions, including those that modify the
database.
At runtime, management commands can change a server's role and
otherwise manage active-backup features. See Active-Backup Commands,
below, for more information.
- --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.
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-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.
- --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 /var/run/openvswitch. If --unixctl is not
used at all, the default socket is
/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 database db in-place. If db is not specified,
compacts every database in-place. A database is also compacted
automatically when a transaction is logged if it is over 2 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. It will also be compacted automatically after 24 hours since
the last compaction if 100 commits were added regardless of its size.
- 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.
These commands query and update the role of ovsdb-server
within an active-backup pair of servers. See Active-Backup Options,
above, and Active-Backup Database Service Model in ovsdb(7)
for more information.
- ovsdb-server/set-active-ovsdb-server
server
- Sets the active server from which ovsdb-server connects
through ovsdb-server/connect-active-ovsdb-server. This overrides
the --sync-from command-line option.
- 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
- Switches the server to a backup role. The server starts synchronizing its
databases with the active server specified by
ovsdb-server/set-active-ovsdb-server (or the --sync-from
command-line option) and closes all existing client connections, which
requires clients to reconnect.
- ovsdb-server/disconnect-active-ovsdb-server
- Switches the server to an active role. The server stops synchronizing its
databases with an active server and closes all existing client
connections, which requires clients to reconnect.
- ovsdb-server/set-sync-exclude-tables
db:table[,db:table]...
- Sets the table within db that will be excluded from
synchronization. This overrides the --sync-exclude-tables
command-line option.
- 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.
These commands support the ovsdb-server clustered service
model. They apply only to databases in the format used for clustered
databases, which is the database format created by ovsdb-tool
create-cluster and ovsdb-tool join-cluster.
- cluster/cid
db
- Prints the cluster ID for db, which is a UUID that identifies the
cluster. If db is a database newly created by ovsdb-tool
cluster-join that has not yet successfully joined its cluster, and
--cid was not specified on the cluster-join command line,
then this command will report an error because the cluster ID is not yet
known.
- cluster/sid
db
- Prints the server ID for db, which is a UUID that identifies this
server within the cluster.
- cluster/status
db
- Prints this server's status within the cluster and the status of its
connections to other servers in the cluster.
- cluster/leave
db
- This command starts the server gracefully removing itself from its
cluster. At least one server must remain, and the cluster must be healthy,
that is, over half of the cluster's servers must be up.
- When the server successfully leaves the cluster, it stops serving
db, as if ovsdb-server/remove-db db had been
executed.
- Use ovsdb-client wait (see ovsdb-client(1)) to wait until
the server has left the cluster.
- cluster/kick
db server
- Start graceful removal of server from db's cluster, like
cluster/leave (without --force) except that it can remove
any server, not just this one.
- server may be a server ID, as printed by cluster/sid, or the
server's local network address as passed to ovsdb-tool's
create-cluster or join-cluster command. Use
cluster/status to see a list of cluster members.
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.
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.
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.
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).