LATEST VERSION: 2.2.0 - RELEASE NOTES
Pivotal GemFire®-Greenplum® Connector v2.2

Using The Connector

To use the connector, download the single JAR file from the Pivotal GemFire product page. The gemfire-greenplum-2.2.0.jar is for the 2.2.0 version of the connector. Include this JAR in the classpath by setting the CLASSPATH environment variable:

export CLASSPATH=$CLASSPATH:/path/to/gemfire-greenplum-2.2.0.jar

Start Pivotal GemFire® locator and server components with the --include-system-classpath option such that they use the environment variable, and can use the connector:

gfsh>start locator --name=loc1 --include-system-classpath
gfsh>start server  --name=s1 --cache-xml-file=/path/to/cache.xml --include-system-classpath

When a second server is started, the second server will fail to start under each of the following situations:

  • If two cache.xml files have different GPDB table names mapped to the same GemFire region.

  • If two cache.xml files map a different set of id fields. This implies that the gpdb:id element must be fully specified; it cannot be empty.

  • If two cache.xml files have different content for their gpdb:field elements. Note that if both have an empty gpdb:fields element, the second server can start. For differing content in the cache.xml files, the situations that cause the second server to fail include:

    • no gpdb:field elements are specified for the first server, and all the gpdb:field elements are specified for the second server
    • no gpdb:field elements are specified for the second server, and all the gpdb:field elements are specified for the first server
    • no gpdb:field elements are specified for the first server, and some gpdb:field elements are specified for the second server
    • no gpdb:field elements are specified for the second server, and some gpdb:field elements are specified for the first server

Connector Requirements and Caveats

  • Export is supported from partitioned GemFire regions only. Data cannot be exported from replicated regions. Data can be imported to replicated regions.

  • The number of Pivotal Greenplum® Database (GPDB) segments must be greater than or equal to the number of Pivotal GemFire servers. If there is a high ratio of GPDB segments to GemFire servers, the GPDB configuration parameter gp_external_max_segs may be used to limit GPDB concurrency. See gp_external_max_segs for details on this parameter. An approach to finding the best setting begins with identifying a representative import operation.

    • Measure the performance of the representative import operation with the default setting.
    • Measure again with gp_external_max_segs set to half the total number of GPDB segments. If there is no gain in performance, then the parameter does not need to be adjusted.
    • Iterate with values of gp_external_max_segs that are half as much at each iteration, until there is no performance improvement or the value of gp_external_max_segs is the same as the number of GemFire servers.