Single table migration tool - mxgate

MatrixGate supports migration mode since 4.3, and can quickly migrate table data from Greenplum5, Greenplum6 and YMatrix clusters to the current YMatrix cluster.

1 High-speed migration principle

High-speed migration allows data to bypass the Master node and read directly from the source cluster segment, forwarded by mxgate, and sent to the target cluster segment. There is no Master single-node bottleneck.

The number of Segments in the source cluster and the target cluster may be inconsistent.

![](https://img.ymatrix.cn/ymatrix_home/mxgate single table migration (screenshot)_1693981479.png)

2 How to use

2.1 Single table migration

Single table migration is used to migrate data from all tables, and the usage is as follows:

mxgate --source transfer \
         --src-host 172.31.41.7 \
         --src-port 5432 \
         --src-db postgres \
         --src-user ec2-user \
         --src-password abc \
         --src-schema public \
         --src-table trans_ao \
         --compress "gzip" \
         --port-base 9129 \
         --local-ip 172.31.33.128 \
         --db-database ttt \
         --target public.trans_ao \
         --format text \
         --time-format raw \
         --use-auto-increment=false

in:

Parameter name	Description
--source	Function portal, 'transfer' must be specified
--src-host	IP address of source library master
--src-port	Port number of source library master
--src-user	Username for connecting to the source library (superuser is recommended)
--src-password	Connection Password
--src-schema	schema name of the source table
--src-table	Table name of the source table
--compress	Transfer method from the source database segment host to this data: The blank string "" means non-compression, plain text transmission gzip: Using gzip compression, the linux command gzip that requires the source database must be installed on the segment host lz4: Using lz4 compression, the linux command lz4 that requires the source database must be installed on the segment host recommended lz4 > gzip > non-compression
--port-base	A batch of ports will be occupied during transmission, and the port range is 9129~
--local-ip	The IP address that must be connected to the local machine using the source library
--db-database	The database name where the migration target table is located
--target	The migration target table name can be in the form of \<schema>.\<table>. If the schema name is not written, the default is public
--format	text or csv, CSV is required only if there are complex strings (including newlines, quotes, and separators) in the migrated data. When both text/csv are available in other cases, text mode is preferred
--time-format	must be raw in transfer mode
--use-auto-increment	When the target table includes a self-increment field of serial type, the fields of this type will be skipped by default in mxgate. This option is added to close the logic of skipping mxgate

2.2 Export to file

Another usage of migration mode is to quickly export data to a file:

mxgate --source transfer \
         --src-host 172.31.41.7 \
         --src-port 5432 \
         --src-db postgres \
         --src-user ec2-user \
         --src-schema public \
         --src-table trans_ao_1 \
         --compress "lz4" \
         --port-base 9129 \
         --local-ip 172.31.33.128 \
         --save-to-dir /tmp/receive/ \
         --db-database ttt \
         --transform nil \
         --writer nil \
         --target trans_ao

Use the --save-to-dir parameter to specify the file storage path.

Note that even if exported to a file, the --db-database and --target parameters need to be given to specify the target library and table, and the target library and table must exist

2.3 Filter migration

Filtering migration can be specified by SQL to filter data that needs to be synchronized by using the --src-sql parameter. It can be used in table-to-table migration and table-to-file migration:

mxgate --source transfer \
         --src-host 172.31.41.7 \
         --src-port 5432 \
         --src-db postgres \
         --src-user ec2-user \
         --src-sql "select * from demo where c1 = 'xxxx'" \
         --compress "lz4" \
         --port-base 9129 \
         --local-ip 172.31.33.128 \
         --save-to-dir /tmp/receive/ \
         --db-database ttt \
         --transform nil \
         --writer nil \
         --target trans_ao

For detailed parameters of the migration tool, please refer to mxgate.