dremio 联邦数据源arp 扩展简单说明
dremio 联邦查询dremio 从代码上没太多高深的东西，实际上也是一个arp 扩展 ，同时官方做了不少优化
核心参考
主要是关于arp 扩展的
- conf 类
@SourceType(
value = "DREMIOTODREMIO",
label = "Dremio-to-Dremio (preview)",
uiConfig = "dremio-to-dremio-layout.json",
externalQuerySupported = true
)
public class DremioToDremioConf extends AbstractArpConf<DremioToDremioConf> {
// dremio-to-dremio-arp.yaml 类型处理的，很不错值得看看
private static final String ARP_FILENAME = "arp/implementation/dremio-to-dremio-arp.yaml";
private static final DremioToDremioDialect DREMIO_TO_DREMIO_ARP_DIALECT = (DremioToDremioDialect)AbstractArpConf.loadArpFile("arp/implementation/dremio-to-dremio-arp.yaml", DremioToDremioDialect::new);
@Tag(1)
@DisplayMetadata(
label = "Endpoint Type"
)
public DremioToDremioConf.HostType hostType;
@NotBlank
@Tag(2)
@DisplayMetadata(
label = "Host"
)
public String hostname;
@NotBlank
@Tag(3)
@Min(1L)
@Max(65535L)
@DisplayMetadata(
label = "Port"
)
public String port;
@Tag(4)
@DisplayMetadata(
label = "Username"
)
public String username;
@Tag(5)
@DisplayMetadata(
label = "Password"
)
@Secret
public String password;
@Tag(6)
@DisplayMetadata(
label = "Use SSL"
)
public boolean useSsl;
@Tag(7)
@DisplayMetadata(
label = "User Impersonation"
)
public boolean userImpersonation;
@Tag(8)
@DisplayMetadata(
label = "Maximum idle connections"
)
@NotMetadataImpacting
public int maxIdleConns;
@Tag(9)
@DisplayMetadata(
label = "Connection idle time (s)"
)
@NotMetadataImpacting
public int idleTimeSec;
@Tag(10)
@DisplayMetadata(
label = "Query timeout (s)"
)
@NotMetadataImpacting
public int queryTimeoutSec;
public DremioToDremioConf() {
this.hostType = DremioToDremioConf.HostType.DIRECT;
this.port = "31010";
this.maxIdleConns = 8;
this.idleTimeSec = 60;
this.queryTimeoutSec = 0;
}
// 官方基于commons-dbcp2 开发的数据源，具体参考源码
private CloseableDataSource newDataSource() {
DremioToDremioPoolDataSource dataSource = new DremioToDremioPoolDataSource(this);
return CloseableDataSource.wrap(dataSource);
}
// jdbc 配置，包含了方言以及数据源创建的
public JdbcPluginConfig buildPluginConfig(Builder configBuilder, CredentialsService credentialsService, OptionManager optionManager) {
return configBuilder.withDialect(this.getDialect()).withDatasourceFactory(this::newDataSource).withShowOnlyConnDatabase(true).withQueryTimeout(this.queryTimeoutSec).build();
}
public DremioToDremioDialect getDialect() {
return DREMIO_TO_DREMIO_ARP_DIALECT;
}
@VisibleForTesting
// 官方标准方言处理
public static DremioToDremioDialect getDialectSingleton() {
return DREMIO_TO_DREMIO_ARP_DIALECT;
}
public static enum HostType {
@Tag(0)
DIRECT,
@Tag(1)
ZOOKEEPER;
}
}
- DremioToDremioDialect 方言
public class DremioToDremioDialect extends ArpDialect {
public DremioToDremioDialect(ArpYaml yaml) {
super(yaml);
}
public DremioToDremioRelToSqlConverter getConverter() {
// 关系算子转sql 的
return new DremioToDremioRelToSqlConverter(this);
}
}
- DremioToDremioRelToSqlConverter 扩展
public class DremioToDremioRelToSqlConverter extends JdbcDremioRelToSqlConverter {
public DremioToDremioRelToSqlConverter(JdbcDremioSqlDialect dremioDialect) {
super(dremioDialect);
}
protected JdbcDremioRelToSqlConverter getJdbcDremioRelToSqlConverter() {
return this;
}
// 目前看主要是对于sql 做了一些处理
public void addSelect(List<SqlNode> selectList, SqlNode node, RelDataType rowType) {
String name = (String)rowType.getFieldNames().get(selectList.size());
String alias = SqlValidatorUtil.getAlias((SqlNode)node, -1);
if (alias == null || !alias.equals(name)) {
name = AliasSanitizer.sanitizeAlias(name);
node = SqlStdOperatorTable.AS.createCall(POS, new SqlNode[]{(SqlNode)node, new SqlIdentifier(name, POS)});
}
selectList.add(node);
}
}
- arp 类型映射
参考图，具体查看源码，因为不支持catalog 所以配置了catalog 为false
