Ubuntu Manpage: ovsdb-server - Open vSwitch database server

Provided by: openvswitch-common_2.13.8-0ubuntu1.4_amd64

NAME

       ovsdb-server - Open vSwitch database server

SYNOPSIS

       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]]

       Active-backup options:
              [--sync-from=server] [--sync-exclude-tables=db:table[,db:table]...]  [--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

       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
       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.

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 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 /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.

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 /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. 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.

• 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 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.

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 /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.

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 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/memory-trim-on-compaction on|off
If this option is on, ovsdb-server will try to reclaim all unused heap memory back to the system
after each successful database 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 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.

Active-Backup Commands
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-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 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.

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 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.

Once a server leaves a cluster, it may never rejoin it. Instead, create a new server and join it
to 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.

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 random 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, according 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 (committed), 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 contains 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 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).

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.

coverage/read-counter counter
Displays the total count for the given coverage counter.

BUGS