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mongooplog
mongooplog
¶
New in version 2.2.
Synopsis¶
mongooplog
is a simple tool that polls operations from
the replication oplog of a remote server, and applies
them to the local server. This capability supports certain classes of
real-time migrations that require that the source server remain online
and in operation throughout the migration process.
Typically this command will take the following form:
This command copies oplog entries from the mongod
instance
running on the host mongodb0.example.net
and duplicates
operations to the host mongodb1.example.net
. If you do not need
to keep the --from
host running during
the migration, consider using mongodump
and
mongorestore
or another backup operation, which may be better suited to
your operation.
Note
If the mongod
instance specified by the --from
argument is running with authentication
, then
mongooplog
will not be able to copy oplog entries.
See also
mongodump
, mongorestore
,
MongoDB Backup Methods, Replica Set Oplog.
Options¶
-
mongooplog
¶
-
--help
¶
Returns information on the options and use of mongooplog.
-
--verbose
,
-v
¶
Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the
-v
form by including the option multiple times, (e.g.-vvvvv
.)
-
--quiet
¶
Runs the mongooplog in a quiet mode that attempts to limit the amount of output.
This option suppresses:
- connection accepted events
- connection closed events
-
--version
¶
Returns the mongooplog release number.
-
--host
<hostname><:port>
,
-h
<hostname><:port>
¶ Specifies a resolvable hostname for the
mongod
instance to whichmongooplog
will apply oplog operations retrieved from the server specified by the--from
option.By default mongooplog attempts to connect to a MongoDB instance running on the localhost on port number
27017
.To connect to a replica set, specify the
replica set name
and a seed list of set members. Use the following form:You can always connect directly to a single MongoDB instance by specifying the host and port number directly.
-
--port
¶
Specifies the port number of the
mongod
instance wheremongooplog
will apply oplog entries. Specify this option only if the MongoDB instance to connect to is not running on the standard port of27017
. You may also specify a port number using the--host
command.
-
--ipv6
¶
Enables IPv6 support and allows the mongooplog to connect to the MongoDB instance using an IPv6 network. All MongoDB programs and processes disable IPv6 support by default.
-
--ssl
¶
New in version 2.6.
Enables connection to a
mongod
ormongos
that has TLS/SSL support enabled.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
-
--sslCAFile
<filename>
¶ New in version 2.6.
Specifies the
.pem
file that contains the root certificate chain from the Certificate Authority. Specify the file name of the.pem
file using relative or absolute paths.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
Warning
If the
mongo
shell or any other tool that connects tomongos
ormongod
is run without--sslCAFile
, it will not attempt to validate server certificates. This results in vulnerability to expiredmongod
andmongos
certificates as well as to foreign processes posing as validmongod
ormongos
instances. Ensure that you always specify the CA file against which server certificates should be validated in cases where intrusion is a possibility.
-
--sslPEMKeyFile
<filename>
¶ New in version 2.6.
Specifies the
.pem
file that contains both the TLS/SSL certificate and key. Specify the file name of the.pem
file using relative or absolute paths.This option is required when using the
--ssl
option to connect to amongod
ormongos
that hasCAFile
enabled withoutweakCertificateValidation
.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
-
--sslPEMKeyPassword
<value>
¶ New in version 2.6.
Specifies the password to de-crypt the certificate-key file (i.e.
--sslPEMKeyFile
). Use the--sslPEMKeyPassword
option only if the certificate-key file is encrypted. In all cases, the mongooplog will redact the password from all logging and reporting output.If the private key in the PEM file is encrypted and you do not specify the
--sslPEMKeyPassword
option, the mongooplog will prompt for a passphrase. See SSL Certificate Passphrase.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
-
--sslCRLFile
<filename>
¶ New in version 2.6.
Specifies the
.pem
file that contains the Certificate Revocation List. Specify the file name of the.pem
file using relative or absolute paths.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
-
--sslAllowInvalidCertificates
¶
New in version 2.6.
Bypasses the validation checks for server certificates and allows the use of invalid certificates. When using the
allowInvalidCertificates
setting, MongoDB logs as a warning the use of the invalid certificate.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
-
--sslFIPSMode
¶
New in version 2.6.
Directs the mongooplog to use the FIPS mode of the installed OpenSSL library. Your system must have a FIPS compliant OpenSSL library to use the
--sslFIPSMode
option.The default distribution of MongoDB does not contain support for TLS/SSL. For more information on MongoDB and TLS/SSL, see Configure mongod and mongos for TLS/SSL.
-
--username
<username>
,
-u
<username>
¶ Specifies a username with which to authenticate to a MongoDB database that uses authentication. Use in conjunction with the
--password
and--authenticationDatabase
options.
-
--password
<password>
,
-p
<password>
¶ Specifies a password with which to authenticate to a MongoDB database that uses authentication. Use in conjunction with the
--username
and--authenticationDatabase
options.If you do not specify an argument for
--password
, mongooplog will prompt interactively for a password on the console.
-
--authenticationDatabase
<dbname>
¶ New in version 2.4.
Specifies the database that holds the user’s credentials.
-
--authenticationMechanism
<name>
¶ Default: MONGODB-CR
New in version 2.4.
Changed in version 2.6: Added support for the
PLAIN
andMONGODB-X509
authentication mechanisms.Specifies the authentication mechanism the mongooplog instance uses to authenticate to the
mongod
ormongos
.Value Description MONGODB-CR MongoDB challenge/response authentication. MONGODB-X509 MongoDB TLS/SSL certificate authentication. PLAIN External authentication using LDAP. You can also use PLAIN
for authenticating in-database users.PLAIN
transmits passwords in plain text. This mechanism is available only in MongoDB Enterprise.GSSAPI External authentication using Kerberos. This mechanism is available only in MongoDB Enterprise.
-
--gssapiServiceName
¶
New in version 2.6.
Specify the name of the service using GSSAPI/Kerberos. Only required if the service does not use the default name of
mongodb
.This option is available only in MongoDB Enterprise.
-
--gssapiHostName
¶
New in version 2.6.
Specify the hostname of a service using GSSAPI/Kerberos. Only required if the hostname of a machine does not match the hostname resolved by DNS.
This option is available only in MongoDB Enterprise.
-
--dbpath
<path>
¶ Specifies a directory, containing MongoDB data files, to which
mongooplog
will apply operations from the oplog of the database specified with the--from
option.When used, the
--dbpath
option enablesmongo
to attach directly to local data files and write data without a runningmongod
instance.To run with
--dbpath
,mongooplog
needs to restrict access to the data directory: as a result, nomongod
can be access the same path while the process runs.
-
--directoryperdb
¶
When used in conjunction with the corresponding option in
mongod
, allows the mongooplog to access data from MongoDB instances that use an on-disk format where every database has a distinct directory. This option is only relevant when specifying the--dbpath
option.
-
--journal
¶
Enables the durability journal to ensure data files remain valid and recoverable. This option applies only when you specify the . The mongooplog enables journaling by default on 64-bit builds of versions after 2.0.
-
--collection
<collection>
,
-c
<collection>
¶ The
--collection
option and its alias-c
are inoperative.
-
--seconds
<number>
,
-s
<number>
¶ Specify a number of seconds of operations for
mongooplog
to pull from theremote host
. Unless specified the default value is86400
seconds, or 24 hours.
-
--from
<host[:port]>
¶ Specify the host for
mongooplog
to retrieve oplog operations from.mongooplog
requires this option.Unless you specify the
--host
option,mongooplog
will apply the operations collected with this option to the oplog of themongod
instance running on the localhost interface connected to port27017
.
-
--oplogns
<namespace>
¶ Specify a namespace in the
--from
host where the oplog resides. The default value islocal.oplog.rs
, which is the where replica set members store their operation log. However, if you’ve copied oplog entries into another database or collection or are pulling oplog entries from a master-slave deployment, use--oplogns
to apply oplog entries stored in another location. Namespaces take the form of[database].[collection]
.
Use¶
Consider the following prototype mongooplog
command:
Here, entries from the oplog of the mongod
running
on port 27017
. This only pull entries from the last 24 hours.
Use the --seconds
argument to capture
a greater or smaller amount of time. Consider the following example:
In this operation, mongooplog
captures 2 full days of
operations. To migrate 12 hours of oplog entries, use the
following form:
For the previous two examples, mongooplog
migrates entries
to the mongod
process running on the localhost interface
connected to the 27017
port. mongooplog
can also
operate directly on MongoDB’s data files if no mongod
is
running on the target host. Consider the following example:
Here, mongooplog
imports oplog operations from the
mongod
host connected to port 27017
. This migrates
operations to the MongoDB data files stored in the /srv/mongodb
directory. Additionally mongooplog
will use the durability
journal to ensure that the data files remain valid.