Installation of the MongoDB replication requires special configuration of the Source and Target hosts so that each is configured for the correct datasource type.
To configure the Applier replicators:
Before installing the applier, the following addition needs adding to the extractor configuration. Apply the following parameters on the extractor host, update the extractor using the details below, and then install the applier
For Staging installs:
shell>cd tungsten-replicator-6.1.25-6shell>./tools/tpm configure alpha \ --enable-heterogeneous-master=trueshell>./tools/tpm update
For INI installs:
Add the following the /etc/tungsten/tungsten.ini
[alpha]
...Existing Replicator Config...
enable-heterogeneous-master=true
shell> tpm updateUnpack the Tungsten Replicator distribution in staging directory:
shell> tar zxf tungsten-replicator-6.1.25-6.tar.gzChange into the staging directory:
shell> cd tungsten-replicator-6.1.25-6Configure the installation using tpm:
shell>./tools/tpm configure defaults \ --reset \ --install-directory=/opt/continuent \ --profile-script=~/.bash_profile \ --disable-security-controls=false \ --rmi-ssl=false \ --thl-ssl=false \ --rmi-authentication=false \ --rest-api-admin-user=apiuser \ --rest-api-admin-pass=secretshell>./tools/tpm configure alpha \ --master=sourcehost \ --members=localhost \ --datasource-type=mongodb \ --replication-user=tungsten \ --replication-password=secret \ --svc-applier-filters=dropstatementdata \ --role=slave \ --replication-host=atlasendpoint.mongodb.net \ --replication-port=27017 \ --property=replicator.applier.dbms.connectString=mongodb+srv://${replicator.global.db.user}:${replicator.global.db.password}@${replicator.global.db.host}/?retryWrites=true&w=majority
shell> vi /etc/tungsten/tungsten.ini[defaults] install-directory=/opt/continuent profile-script=~/.bash_profile disable-security-controls=false rmi-ssl=false thl-ssl=false rmi-authentication=false rest-api-admin-user=apiuser rest-api-admin-pass=secret[alpha] master=sourcehost members=localhost datasource-type=mongodb replication-user=tungsten replication-password=secret svc-applier-filters=dropstatementdata role=slave replication-host=atlasendpoint.mongodb.net replication-port=27017 property=replicator.applier.dbms.connectString=mongodb+srv://${replicator.global.db.user}:${replicator.global.db.password}@${replicator.global.db.host}/?retryWrites=true&w=majority
Configuration group defaults
The description of each of the options is shown below; click the icon to hide this detail:
For staging configurations, deletes all pre-existing configuration information between updating with the new configuration values.
--install-directory=/opt/continuent
install-directory=/opt/continuent
Path to the directory where the active deployment will be installed. The configured directory will contain the software, THL and relay log information unless configured otherwise.
--profile-script=~/.bash_profile
profile-script=~/.bash_profile
Append commands to include env.sh in this profile script
--disable-security-controls=false
disable-security-controls=false
Disables all forms of security, including SSL, TLS and authentication
Enable SSL encryption of RMI communication on this host
Enable SSL encryption of THL communication for this service
Enable RMI authentication for the services running on this host
--rest-api-admin-user=apiuser
rest-api-admin-user=apiuser
--rest-api-admin-pass=secret
rest-api-admin-pass=secret
Configuration group alpha
The description of each of the options is shown below; click the icon to hide this detail:
The hostname of the primary (extractor) within the current service.
Hostnames for the dataservice members
Database type
For databases that required authentication, the username to use when connecting to the database using the corresponding connection method (native, JDBC, etc.).
The password to be used when connecting to the database using
the corresponding
--replication-user.
--svc-applier-filters=dropstatementdata
svc-applier-filters=dropstatementdata
Replication service applier filters
What is the replication role for this service?
--replication-host=atlasendpoint.mongodb.net
replication-host=atlasendpoint.mongodb.net
Hostname of the datasource where the database is located. If the specified hostname matches the current host or member name, the database is assumed to be local. If the hostnames do not match, extraction is assumed to be via remote access. For MySQL hosts, this configures a remote replication Replica (relay) connection.
The network port used to connect to the database server. The default port used depends on the database being configured.
The --property option enables
you to explicitly set property values in the target files. A
number of different models are supported:
key=value
Set the property defined by
key to the specified
value without evaluating any template values or other rules.
key+=value
Add the value to the property defined by
key. Template values and
other options append their settings to the end of the
specified property.
key~=/match/replace/
Evaluate any template values and other settings, and then
perform the specified Ruby regex operation to the property
defined by key. For
example
--property=replicator.key~=/(.*)/somevalue,\1/
will prepend somevalue
before the template value for
replicator.key.
Once the prerequisites and configuring of the installation has been completed, the software can be installed:
shell> ./tools/tpm install
If the installation process fails, check the output of the
/tmp/tungsten-configure.log file for
more information about the root cause.
The above example assumes SSL is not enabled between the extractor and applier replicators.
If SSL is required, then you must omit the following
properties from the example configs displayed above, or change the values to true:
rmi-ssl=false, thl-ssl=false, rmi-authentication=false
Once you have installed the replicator, there are a few more steps required to allow the replicator to be able to authenticate with MongoDB Atlas.
MongoDB Atlas requires TLS connections for all Atlas Clusters, therefore we need to configure the replicator to recognise this.
From May 1, 2021, MongoDB Atlas has moved to new TLS Certificiates using ISRG instead of IdenTrust for their root Certificate Authority.
All new clusters created after this time, or any existing clusters that have since been migrated to this new root CA will need to follow the correct procedure to configure the replicator. Both procedures are below, follow the correct one that relates to your configuration.
For MongoDB Atlas Cluster created PRIOR to May 1, 2021, or that have not yet migrated to the new LetsEncrypt root Certificate:
Using the correct Atlas Endpoint, issue the following command to retrieve the Atlas certificates
shell> openssl s_client -showcerts -connect atlas-endpoint.mongodb.net:27017The output may be quite long and will include at least two certificates bound by the header/footer as follows
-----BEGIN CERTIFICATE----- xxxx xxxx -----END CERTIFICATE-----
Copy each certificate, including the header/footer, into individual files
Using keytool, we now need to load each certificte into the truststore that was created during the replicator installation. Repeat the example below for each certificate, ensuring you use a unique alias name for each certificate.
shell> keytool -import -alias your-alias1 -file cert1.cer -keystore /opt/continuent/share/tungsten_truststore.ts
When prompted, the default password for the truststore will be tungsten unless
you specified a different password during installation
Once this is complete, you can now start the replicator
shell> replicator startFor MongoDB Atlas Cluster created AFTER May 1, 2021, or that have been migrated to the new LetsEncrypt root Certificate:
Obtain the LetsEncrypt root Certificate from here
Copy the certificate into a file called letsencrypt.pem in the home directory of the applier host, including the BEGIN an END header/footer, for example:
-----BEGIN CERTIFICATE----- xxxx xxxx -----END CERTIFICATE-----
Using keytool, we now need to import this certificte into the truststore that was created during the replicator installation.
shell> keytool -import -alias letsencrypt -file letsencrypt.pem -keystore /opt/continuent/share/tungsten_truststore.ts
When prompted, the default password for the truststore will be tungsten unless
you specified a different password during installation
Once this is complete, you can now start the replicator
shell> replicator startOnce the replicators have started, the status of the service can be checked using trepctl. See Section 4.5.5, “Management and Monitoring of MongoDB Deployments” for more information.