Package com.amazonaws.athena.connectors.hbase.connection

Class HBaseConnection

  • public class HBaseConnection
extends Object
    This class wraps Hbase's Connection construct and provides both a simplified facade for common operations but also automatic retry and reconnect logic to make client reuse simpler. Some specific cases that this construct handles are: replacement of an HBase region server, replacement of HBase master server, other transient errors while communicating with HBase.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected HBaseConnection​(org.apache.hadoop.conf.Configuration config, int maxRetries)
      Used by HBaseConnectionFactory to construct new connections.
      protected HBaseConnection​(org.apache.hadoop.hbase.client.Connection connection, int maxRetries)
      Used to facilitate testing by allowing for injection of the underlying HBase connection.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void close()
      Used to close this connection by closing the underlying HBase Connection.
      protected org.apache.hadoop.hbase.client.Connection connect​(org.apache.hadoop.conf.Configuration config)
      Creates a new HBase connection using the provided config.
      protected int getRetries()  
      List<org.apache.hadoop.hbase.HRegionInfo> getTableRegions​(org.apache.hadoop.hbase.TableName tableName)
      Retreieves the regions for the requested TableName.
      boolean isHealthy()
      Used to determine if this connection can be reused or if it is unhealthy.
      org.apache.hadoop.hbase.NamespaceDescriptor[] listNamespaceDescriptors()
      Lists the available namespaces in the HBase instance.
      org.apache.hadoop.hbase.TableName[] listTableNamesByNamespace​(String schemaName)
      Lists the table names present in the given schema (aka namespace)
      <T> T scanTable​(org.apache.hadoop.hbase.TableName tableName, org.apache.hadoop.hbase.client.Scan scan, ResultProcessor<T> resultProcessor)
      Used to perform a scan of the given table, scan, and resultProcessor.
      boolean tableExists​(org.apache.hadoop.hbase.TableName tableName)
      Retrieves whether the table exists

    • Constructor Detail

      • HBaseConnection

        protected HBaseConnection​(org.apache.hadoop.conf.Configuration config,
                          int maxRetries)
        Used by HBaseConnectionFactory to construct new connections.
        Parameters:
        config - The HBase config to use for this connection.
        maxRetries - The max retries this connection will allow before marking itself unhealthy.

      • HBaseConnection

        protected HBaseConnection​(org.apache.hadoop.hbase.client.Connection connection,
                          int maxRetries)
        Used to facilitate testing by allowing for injection of the underlying HBase connection.
        Parameters:
        connection - The actual Hbase connection to use.
        maxRetries - The max retries this connection will allow before marking itself unhealthy.

    • Method Detail

      • isHealthy

        public boolean isHealthy()
        Used to determine if this connection can be reused or if it is unhealthy.
        Returns:
        True if the connection can be safely reused, false otherwise.

      • listNamespaceDescriptors

        public org.apache.hadoop.hbase.NamespaceDescriptor[] listNamespaceDescriptors()
                                                                       throws IOException
        Lists the available namespaces in the HBase instance.
        Returns:
        Array of NamespaceDescriptor representing the available namespaces in the HBase instance.
        Throws:
        IOException

      • listTableNamesByNamespace

        public org.apache.hadoop.hbase.TableName[] listTableNamesByNamespace​(String schemaName)
        Lists the table names present in the given schema (aka namespace)
        Parameters:
        schemaName - The schema name (aka hbase namespace) to list table names from.
        Returns:
        An array of hbase TableName objects for the given schema name.

      • getTableRegions

        public List<org.apache.hadoop.hbase.HRegionInfo> getTableRegions​(org.apache.hadoop.hbase.TableName tableName)
        Retreieves the regions for the requested TableName.
        Parameters:
        tableName - The fully qualified HBase TableName for which we should obtain region info.
        Returns:
        List of HRegionInfo representing the regions hosting the requested table.

      • scanTable

        public <T> T scanTable​(org.apache.hadoop.hbase.TableName tableName,
                       org.apache.hadoop.hbase.client.Scan scan,
                       ResultProcessor<T> resultProcessor)
        Used to perform a scan of the given table, scan, and resultProcessor.
        Type Parameters:
        T - The return type of the ResultProcessor and this this method.
        Parameters:
        tableName - The HBase table to scan.
        scan - The HBase scan (filters, etc...) to run.
        resultProcessor - The ResultProcessor that will be used to process the results of the scan.
        Returns:
        The result produced by the resultProcessor when it has completed processing all results of the scan.

      • tableExists

        public boolean tableExists​(org.apache.hadoop.hbase.TableName tableName)
        Retrieves whether the table exists
        Parameters:
        tableName - The fully qualified HBase TableName for which to check existence.
        Returns:
        Whether the table exists or not.

      • close

        protected void close()
        Used to close this connection by closing the underlying HBase Connection.

      • getRetries

        protected int getRetries()

      • connect

        protected org.apache.hadoop.hbase.client.Connection connect​(org.apache.hadoop.conf.Configuration config)
        Creates a new HBase connection using the provided config.
        Parameters:
        config - The config to use for the new HBase connection.
        Returns:
        The new connection.