ovsdb-server(1) Open vSwitch Manual ovsdb-server(1)
NAME
ovsdb-server - Open vSwitch database server
SYNOPSIS
ovsdb-server [database]... [relay:schema_name:remote]... [--re‐
mote=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]]
Active-backup options:
[--sync-from=server] [--sync-exclude-tables=db:table[,db:ta‐
ble]...] [--active]
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
Replay options:
[--record[=directory]] [--replay[=directory]]
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. For an introduc‐
tion to OVSDB and its implementation in Open vSwitch, see ovsdb(7).
Each OVSDB file may be specified on the command line as database. Re‐
lay databases may be specified on the command line as re‐
lay:schema_name:remote. For a detailed description of relay database
argument, see ovsdb(7). If none of database files or relay databases
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's create, create-cluster, or join-cluster com‐
mand.
This OVSDB implementation supports standalone, active-backup, relay 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. The same is true for relay data‐
bases. Same commands could be used to wait for a relay database to
connect to the relay source (remote).
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.
OPTIONS
--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 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.
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 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 --re‐
mote=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 /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 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
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 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 an‐
other 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 de‐
taches. Otherwise, invoking ovsdb-server from a carelessly cho‐
sen 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 be‐
havior 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-known directories determined during build. 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 implemen‐
tations 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.
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. (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 be‐
low).
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 /usr/local/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. 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 ex‐
ample, 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.
• null, discards all messages logged to syslog.
The default is taken from the OVS_SYSLOG_METHOD environment
variable; if it is unset, the default is libc.
Active-Backup Options
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 ac‐
tive role, but prepared to switch to the backup role in which it
would replicate data from server. When ovsdb-server runs in ac‐
tive mode, it allows all transactions, including those that mod‐
ify the database.
At runtime, management commands can change a server's role and other‐
wise 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 data‐
bases in server, which must be an active connection method in
one of the forms documented in ovsdb-client(1). Every transac‐
tion 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/con‐
nect-active-ovsdb-server command.
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.
SSL Connection Options
--ssl-protocols=protocols
Specifies, in a comma- or space-delimited list, the SSL proto‐
cols 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 cho‐
sen 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 lis‐
tens for runtime management commands (see RUNTIME MANAGEMENT
COMMANDS, below). If socket does not begin with /, it is inter‐
preted as relative to /usr/local/var/run/openvswitch. If
--unixctl is not used at all, the default socket is /usr/lo‐
cal/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 man‐
agement 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 direc‐
tory. The file exists just to mimic the behavior of a Unix do‐
main socket.
Specifying none for socket disables the control socket feature.
--record[=directory]
Sets the process in "recording" mode, in which it will record
all the connections, data from streams (Unix domain and network
sockets) and some other important necessary bits, so they could
be replayed later. Recorded data is stored in replay files in
specified directory. If directory does not begin with /, it is
interpreted as relative to /usr/local/var/run/openvswitch. If
directory is not specified, /usr/local/var/run/openvswitch will
be used.
--replay[=directory]
Sets the process in "replay" mode, in which it will read infor‐
mation about connections, data from streams (Unix domain and
network sockets) and some other necessary bits directly from re‐
play files instead of using real sockets. Replay files from the
directory will be used. If directory does not begin with /, it
is interpreted as relative to /usr/local/var/run/openvswitch.
If directory is not specified, /usr/local/var/run/openvswitch
will be used.
-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 database db in-place. If db is not specified, compacts
every database in-place. A database is also compacted automati‐
cally 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 au‐
tomatically after 24 hours since the last compaction if 100 com‐
mits were added regardless of its size.
ovsdb-server/memory-trim-on-compaction on|off
If this option is on, ovsdb-server will try to reclaim all un‐
used heap memory back to the system after each successful data‐
base compaction to reduce the memory consumption of the process.
off by default.
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. database could
be a database file or a relay description in the following for‐
mat: relay:schema_name:remote. 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 ei‐
ther through the command line or through the ovsdb-server/add-db
command.
ovsdb-server/tlog-set database:table on|off
Enables or disables logging of all operations executed on the
specified database and table. Logs are generated at INFO level
and are rate limtied.
ovsdb-server/tlog-list
Displays the logging state for all currently configured data‐
bases and tables.
Active-Backup Commands
These commands query and update the role of ovsdb-server within an ac‐
tive-backup pair of servers. See Active-Backup Options, above, and Ac‐
tive-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 syn‐
chronizing its databases.
ovsdb-server/connect-active-ovsdb-server
Switches the server to a backup role. The server starts syn‐
chronizing its databases with the active server specified by
ovsdb-server/set-active-ovsdb-server (or the --sync-from com‐
mand-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 syn‐
chronizing its databases with an active server and closes all
existing client connections, which requires clients to recon‐
nect.
ovsdb-server/set-active-ovsdb-server-probe-interval probe interval
Sets the probe interval (in milli seconds) for the connection
to active server.
ovsdb-server/set-sync-exclude-tables db:table[,db:table]...
Sets the table within db that will be excluded from synchroniza‐
tion. This overrides the --sync-exclude-tables command-line op‐
tion.
ovsdb-server/get-sync-exclude-tables
Gets the tables that are currently excluded from synchroniza‐
tion.
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 connec‐
tion is in replicating state, further output shows the list of
databases currently replicating, and the tables that are ex‐
cluded.
Cluster Commands
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 serv‐
ing 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.
Once a server leaves a cluster, it may never rejoin it. In‐
stead, create a new server and join it to the cluster.
Note that removing the server from the cluster alters the total
size of the cluster. For example, if you remove two servers from
a three server cluster, then the "cluster" becomes a single
functioning server. This does not result in a three server
cluster that lacks quorum.
cluster/kick db server
Start graceful removal of server from db's cluster, like clus‐
ter/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 cre‐
ate-cluster or join-cluster command. Use cluster/status to see
a list of cluster members.
cluster/change-election-timer db time
Change the leader election timeout base value of the cluster, in
milliseconds.
Leader election will be initiated by a follower if there is no
heartbeat received from the leader within this time plus a ran‐
dom time within 1 second.
The default value is 1000, if not changed with this command.
This command can be used to adjust the value when necessary, ac‐
cording to the expected load and response time of the servers.
This command must be executed on the leader. It initiates the
change to the cluster. To see if the change takes effect (com‐
mitted), use cluster/status to show the current setting. Once a
change is committed, it persists at server restarts.
cluster/set-backlog-threshold db n_msgs n_bytes
Sets the backlog limits for db's RAFT connections to a maximum
of n_msgs messages or n_bytes bytes. If the backlog on one of
the connections reaches the limit, it will be disconnected (and
re-established). Values are checked only if the backlog con‐
tains more than 50 messages.
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/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 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 us‐
age. 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.
coverage/read-counter counter
Displays the total count for the given coverage counter.
BUGS
In Open vSwitch before version 2.4, when ovsdb-server sent JSON-RPC er‐
ror 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 er‐
ror (assuming that the database being monitored does not contain a ta‐
ble named error).
SEE ALSO
ovsdb(7), ovsdb-tool(1), ovsdb-server(5), ovsdb-server(7).
Open vSwitch 3.2.1 ovsdb-server(1)