If you have an existing dataservice, data can be replicated from a standalone MySQL server into the service. The replication is configured by creating a service that reads from the standalone MySQL server and writes into the cluster through a connector attached to your dataservice. By writing through the connector, changes to the underlying dataservice topology can be handled.
Additionally, using a replicator that writes data into an existing data service can be used when migrating from an existing service into a new Tungsten Cluster service.
For more information on initially provisioning the data for this type of operation, see Section 6.12.2, “Migrating from MySQL Native Replication Using a New Service”.
In order to configure this deployment, there are two steps:
Create a new replicator on the source server that extracts the data.
Create a new replicator that reads the binary logs directly from the external MySQL service through the connector
There are also the following requirements:
The host on which you want to replicate to must have Tungsten Replicator 5.3.0 or later.
Hosts on both the replicator and cluster must be able to communicate with each other.
The replication user on the source host must have the
RELOAD,REPLICATION SLAVE, andREPLICATION CLIENTGRANTprivileges.Replicator must be able to connect as the
tungstenuser to the databases within the cluster.When writing into the Primary through the connector, the user must be given the correct privileges to write and update the MySQL server. For this reason, the easiest method is to use the
tungstenuser, and ensure that that user has been added to theuser.map:tungsten secret alpha
Install the Tungsten Replicator package (see
Section 2.3.2, “Using the RPM package files”), or download the compressed
tarball and unpack it on host1:
shell>cd /opt/replicator/softwareshell>tar zxf tungsten-replicator-6.1.25-6.tar.gz
Change to the Tungsten Replicator staging directory:
shell> cd tungsten-replicator-6.1.25-6
Configure the replicator on host1
First we configure the defaults and a cluster alias that points to the Primaries and Replicas within the current Tungsten Cluster service that you are replicating from:
Click the link below to switch examples between Staging and INI methods
shell> ./tools/tpm configure alpha \
--master=host1 \
--install-directory=/opt/continuent \
--replication-user=tungsten \
--replication-password=password \
--enable-batch-service=true
shell> vi /etc/tungsten/tungsten.ini[alpha]
master=host1
install-directory=/opt/continuent
replication-user=tungsten
replication-password=password
enable-batch-service=true
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.
--install-directory=/opt/continuentinstall-directory=/opt/continuentPath 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.
For databases that required authentication, the username to use when connecting to the database using the corresponding connection method (native, JDBC, etc.).
--replication-password=passwordThe password to be used when connecting to the database using the corresponding
--replication-user.This option enables batch mode for a service, which ensures that replication services that are writing to a target database using batch mode in heterogeneous deployments (for example Hadoop, Amazon Redshift or Vertica). Setting this option enables the following settings on each host:
On a Primary
mysql-use-bytes-for-stringis set to false.colnamesfilter is enabled (in thebinlog-to-qstage to add column names to the THL information.pkeyfilter is enabled (in thebinlog-to-qandq-to-dbmsstage), with theaddPkeyToInsertsandaddColumnsToDeletesfilter options set to true. This ensures that rows have the right primary key information.enumtostringfilter is enabled (in theq-to-thlstage), to translateENUMvalues to their string equivalents.settostringfilter is enabled (in theq-to-thlstage), to translateSETvalues to their string equivalents.
On a Replica
mysql-use-bytes-for-stringis set to true.
This creates a configuration that specifies that the topology should read
directly from the source host, host3,
writing directly to host1. An
alternative THL port is provided to ensure that the THL listener is not
operating on the same network port as the original.
Now install the service, which will create the replicator reading direct
from host3 into
host1:
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.
Once the installation has been completed, you must update the position of the replicator so that it points to the correct position within the source database to prevent errors during replication. If the replication is being created as part of a migration process, determine the position of the binary log from the external replicator service used when the backup was taken. For example:
mysql> show master status;
*************************** 1. row ***************************
File: mysql-bin.000026
Position: 1311
Binlog_Do_DB:
Binlog_Ignore_DB:
1 row in set (0.00 sec)Use dsctl set to update the replicator position to point to the Primary log position:
shell> /opt/replicator/tungsten/tungsten-replicator/bin/dsctl -service beta set \
-reset -seqno 0 -epoch 0 \
-source-id host3 -event-id mysql-bin.000026:1311Now start the replicator:
shell> /opt/replicator/tungsten/tungsten-replicator/bin/replicator startReplication status should be checked by explicitly using the servicename and/or RMI port:
shell> /opt/replicator/tungsten/tungsten-replicator/bin/trepctl -service beta status
Processing status command...
NAME VALUE
---- -----
appliedLastEventId : mysql-bin.000026:0000000000001311;1252
appliedLastSeqno : 5
appliedLatency : 0.748
channels : 1
clusterName : beta
currentEventId : mysql-bin.000026:0000000000001311
currentTimeMillis : 1390410611881
dataServerHost : host1
extensions :
host : host3
latestEpochNumber : 1
masterConnectUri : thl://host3:2112/
masterListenUri : thl://host1:2113/
maximumStoredSeqNo : 5
minimumStoredSeqNo : 0
offlineRequests : NONE
pendingError : NONE
pendingErrorCode : NONE
pendingErrorEventId : NONE
pendingErrorSeqno : -1
pendingExceptionMessage: NONE
pipelineSource : jdbc:mysql:thin://host3:13306/
relativeLatency : 8408.881
resourcePrecedence : 99
rmiPort : 10000
role : master
seqnoType : java.lang.Long
serviceName : beta
serviceType : local
simpleServiceName : beta
siteName : default
sourceId : host3
state : ONLINE
timeInStateSeconds : 8408.21
transitioningTo :
uptimeSeconds : 8409.88
useSSLConnection : false
version : Tungsten Replicator 6.1.25 build 6
Finished status command...