JarCastingswift-hive-metastore
A swift based client for the Hive Metastore. Swift is an annotation based implementation for the Thrift protocol, available from https://github.com/facebook/swift.
Goal of this project is to replace
<dependency>
<groupId>org.apache.hive</groupId>
<artifactId>hive-metastore</artifactId>
</dependency>
as a client library for users of the Hive metastore.
Only supports Thrift based metastores, there is no support for a local metastore. This is intentional to enforce usage of the Thrift API for clients.
The library is supposed to be an API drop-in, it also supports a number of helper APIs from the hive-metastore dependency:
org.apache.hadoop.hive.metastore.MetaStoreUtilsorg.apache.hadoop.hive.metastore.api.hive_metastoreConstantsorg.apache.hadoop.hive.metastore.TableTypeorg.apache.hadoop.hive.metastore.MetaStoreFSorg.apache.hadoop.hive.metastore.ProtectModeorg.apache.hadoop.hive.metastore.Warehouse
All client pieces that are different from the Apache Hive Metastore are located in the com.facebook.hive.metastore package.
Usage
HiveMetastoreClientConfig metastoreConfig = new HiveMetastoreClientConfig();
try (ThriftClientManager clientManager = new ThriftClientManager()) {
ThriftClientConfig clientConfig = new ThriftClientConfig();
HiveMetastoreFactory factory = new SimpleHiveMetastoreFactory(clientManager, clientConfig, metastoreConfig);
try (HiveMetastore metastore = factory.getDefaultClient()) {
Table table = metastore.getTable("hello", "world");
}
}
The Metastore API uses new API names (Java style). For drop-in compatibility, use
HiveMetastoreClientConfig metastoreConfig = new HiveMetastoreClientConfig();
try (ThriftClientManager clientManager = new ThriftClientManager()) {
ThriftClientConfig clientConfig = new ThriftClientConfig();
HiveMetastoreFactory factory = new SimpleHiveMetastoreFactory(clientManager, clientConfig, metastoreConfig);
try (HiveMetastore metastore = factory.getDefaultClient()) {
ThriftHiveMetastore.Client client = ThriftHiveMetastore.Client.forHiveMetastore(metastore);
Table table = client.get_table("hello", "world");
}
}
Using Guice
A Guice module is available that allows integration of the client using dependecy injection with Googl Guice. This requires the ThriftClientModule and the ThriftCodecModule from swift.
Injector inj = Guice.createInjector(Stage.PRODUCTION,
new HiveMetastoreClientModule(),
new ThriftClientModule(),
new ThriftCodecModule());
HiveMetastoreProvider provider = inj.getInstance(HiveMetastoreProvider.class);
HiveMetastore metastore = metastoreProvider.get();
Table table = metastore.getTable("hello", "world");
...
Known problems
Swift does not support unions yet. So ColumnStatisticsData, ColumnStatisticsObj and the associated API calls are not available. This will be fixed in the next release.
