HBase全局一致性事务支持Tephra.zip

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文件名称：HBase全局一致性事务支持Tephra.zip

文件大小：603KB

文件格式：ZIP

更新时间：2022-08-07 21:08:06

开源项目

Tephra 在 Apache HBase 的基础上提供了全局一致性的事务支持。HBase 提供了强一致性的基于行和区域的 ACID 操作支持，但是牺牲了在跨区域操作的支持。这就要求应用开发者花很大力气来确保区域边界上操作的一致性。而 Tephra 提供了全局事务支持，可以夸区域、跨表以及多个 RPC 上简化了应用的开发。示例代码：  /**    * A Transactional SecondaryIndexTable.    */   public class SecondaryIndexTable {     private byte[] secondaryIndex;     private TransactionAwareHTable transactionAwareHTable;     private TransactionAwareHTable secondaryIndexTable;     private TransactionContext transactionContext;     private final TableName secondaryIndexTableName;     private static final byte[] secondaryIndexFamily =       Bytes.toBytes("secondaryIndexFamily");     private static final byte[] secondaryIndexQualifier = Bytes.toBytes('r');     private static final byte[] DELIMITER  = new byte[] {0};     public SecondaryIndexTable(TransactionServiceClient transactionServiceClient,                                HTable hTable, byte[] secondaryIndex) {       secondaryIndexTableName =             TableName.valueOf(hTable.getName().getNameAsString()   ".idx");       HTable secondaryIndexHTable = null;       HBaseAdmin hBaseAdmin = null;       try {         hBaseAdmin = new HBaseAdmin(hTable.getConfiguration());         if (!hBaseAdmin.tableExists(secondaryIndexTableName)) {           hBaseAdmin.createTable(new HTableDescriptor(secondaryIndexTableName));         }         secondaryIndexHTable = new HTable(hTable.getConfiguration(),                                           secondaryIndexTableName);       } catch (Exception e) {         Throwables.propagate(e);       } finally {         try {           hBaseAdmin.close();         } catch (Exception e) {           Throwables.propagate(e);         }       }       this.secondaryIndex = secondaryIndex;       this.transactionAwareHTable = new TransactionAwareHTable(hTable);       this.secondaryIndexTable = new TransactionAwareHTable(secondaryIndexHTable);       this.transactionContext = new TransactionContext(transactionServiceClient,                                                        transactionAwareHTable,                                                        secondaryIndexTable);     }     public Result get(Get get) throws IOException {       return get(Collections.singletonList(get))[0];     }     public Result[] get(List gets) throws IOException {       try {         transactionContext.start();         Result[] result = transactionAwareHTable.get(gets);         transactionContext.finish();         return result;       } catch (Exception e) {         try {           transactionContext.abort();         } catch (TransactionFailureException e1) {           throw new IOException("Could not rollback transaction", e1);         }       }       return null;     }     public Result[] getByIndex(byte[] value) throws IOException {       try {         transactionContext.start();         Scan scan = new Scan(value, Bytes.add(value, new byte[0]));         scan.addColumn(secondaryIndexFamily, secondaryIndexQualifier);         ResultScanner indexScanner = secondaryIndexTable.getScanner(scan);         ArrayList gets = new ArrayList();         for (Result result : indexScanner) {           for (Cell cell : result.listCells()) {             gets.add(new Get(cell.getValue()));           }         }         Result[] results = transactionAwareHTable.get(gets);         transactionContext.finish();         return results;       } catch (Exception e) {         try {           transactionContext.abort();         } catch (TransactionFailureException e1) {           throw new IOException("Could not rollback transaction", e1);         }       }       return null;     }     public void put(Put put) throws IOException {       put(Collections.singletonList(put));     }     public void put(List puts) throws IOException {       try {         transactionContext.start();         ArrayList secondaryIndexPuts = new ArrayList();         for (Put put : puts) {           List indexPuts = new ArrayList();           Set>> familyMap = put.getFamilyMap().entrySet();           for (Map.Entry> family : familyMap) {             for (KeyValue value : family.getValue()) {               if (value.getQualifier().equals(secondaryIndex)) {                 byte[] secondaryRow = Bytes.add(value.getQualifier(),                                                 DELIMITER,                                                 Bytes.add(value.getValue(),                                                 DELIMITER,                                                 value.getRow()));                 Put indexPut = new Put(secondaryRow);                 indexPut.add(secondaryIndexFamily, secondaryIndexQualifier, put.getRow());                 indexPuts.add(indexPut);               }             }           }           secondaryIndexPuts.addAll(indexPuts);         }         transactionAwareHTable.put(puts);         secondaryIndexTable.put(secondaryIndexPuts);         transactionContext.finish();       } catch (Exception e) {         try {           transactionContext.abort();         } catch (TransactionFailureException e1) {           throw new IOException("Could not rollback transaction", e1);         }       }     }   } 标签：Tephra