Database Replication and Clustering
The provisioning process can be controlled using a number of properties
that can be configured when the replicator is installed by using
--property
option. For example:
shell> tpm update alpha \
--property=replicator.extractor.parallel-extractor.ChunkDefinitionFile=/opt/continuent/share/chunks.csv
replicator.extractor.parallel-extractor.ChunkDefinitionFile
The path to a file that contains a specification of the tables that should be included in the extraction. If no file is specified then all tables and extracted for provisioning.
The format of the chunk definition file is a Comma Separated Values (CSV) file, with each line containing the schema name, optional table name, optional chunk size and optional column list to be extracted. For example:
SALES
Would extract all tables within the schema
SALES
:
SALES,INVOICES
Would extract only the INVOICES
table from the SALES
schema.
SALES,INVOICES,1000
Would extract only the INVOICES
table from the SALES
schema,
only in chunks of 1000 rows.
To extract only specific columns, add the column list to the end of the schema, table and chunk size. For example:
SALES,INVOICES,1000,INVOICENO,CUSTOMERID,VALUE
Multiple lines can be used to define a range of schemas, tables, and chunk size combinations.
replicator.extractor.parallel-extractor.chunk_size
The chunk size defines the number of rows that are extracted from the source tables and inserted into the THL. This number should be adjusted when extracting very large rows from the source tables.
replicator.extractor.parallel-extractor.add_truncate_table
If set to true
, a
TRUNCATE
statement is inserted
into the THL before the first row data is inserted into the THL. This
empties the target table before the provision data is replicated.
replicator.extractor.parallel-extractor.extract_channels
Specifies the number of simultaneous threads that will be used to extract information. Defaults to a single thread.
replicator.extractor.parallel-extractor.queue_size
The number of events buffered inside the parallel extractor before they are inserted into the THL. Defaults to 20 transactions.