please remove me from this mail list On Fri, Oct 23, 2015 at 12:59 PM, Apache Wiki <wikidi...@apache.org> wrote:
> Dear Wiki user, > > You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for > change notification. > > The "Hbase/Plan-0.2/APIChanges" page has been changed by Misty: > > https://wiki.apache.org/hadoop/Hbase/Plan-0.2/APIChanges?action=diff&rev1=5&rev2=6 > > - = Changes to HBaseAdmin and HTable between HBase 0.1.3 and 0.2 = > + The HBase Wiki is in the process of being decommissioned. The info that > used to be on this page has moved to > http://hbase.apache.org/book.html#hbase.versioning. Please update your > bookmarks. > > - == General Changes == > - > - The APIs for both `HBaseAdmin` and `HTable` have significantly changed > between versions 0.1.3 and 0.2.x. 0.2.x is NOT backward-compatible. The > following document summarizes the key differences that are most important > for developers wishing to use these classes. For more information, see the > full API documentations for [[ > http://hadoop.apache.org/hbase/docs/current/api/index.html|0.1.3]] and > [0.2]. > - > - A general difference in both `HBaseAdmin` and `HTable` is a transition > away from using Hadoop's `Text` class (package `org.apache.hadoop.io`) > and toward using `byte[]` as a replacement. All methods from 0.1.3 that > returned either `Text` or `Text[]` now return either `byte[]` or `byte[][]` > or the fatter `RowResult`. HBase 0.2 has not completely abandoned the use > of `Text`. All methods that once accepted parameters of type `Text` are > now overloaded to support `Text`, `String`, or `byte[]` as parameters. The > following API changes from `HBaseAdmin` demonstrate this overloading: > - > - ''0.1.3:'' > - <<BR>> {{{public void addColumn(Text, HColumnDescriptor);}}} > - <<BR>> {{{public void deleteColumn(Text, Text);}}} > - > - ''0.2:'' > - <<BR>> {{{public void addColumn(Text, HColumnDescriptor);}}} > - <<BR>> {{{public void addColumn(String, HColumnDescriptor);}}} > - <<BR>> {{{public void addColumn(byte[], HColumnDescriptor);}}} > - <<BR>> {{{public void deleteColumn(Text, Text);}}} > - <<BR>> {{{public void deleteColumn(String, String);}}} > - <<BR>> {{{public void deleteColumn(byte[], byte[]);}}} > - > - == HBaseAdmin == > - > - Aside from the method overloading described above, `HBaseAdmin` has not > significantly changed. HBase 0.2 adds the following new methods to > `HBaseAdmin`: > - > - ''0.2:'' > - <<BR>> {{{public boolean isTableEnabled(Text);}}} > - <<BR>> {{{public boolean isTableEnabled(String);}}} > - <<BR>> {{{public boolean isTableEnabled(byte[]);}}} > - <<BR>> {{{public void modifyTableMeta(byte[] HTableDescriptor);}}} > - > - The only method in `HBaseAdmin` from 0.1.3 that no longer exists in > HBase 0.2 is `checkReservedTableName(Text)`. These changes aside, the API > and functional capability of `HBaseAdmin` has not drastically changed > between versions 0.1.3 and 0.2. > - > - == HTable == > - > - `HTable` has experienced far more significant changes to its API and > functional capability. The biggest change is the way in which row updates > are performed. In HBase 0.1.3, `HTable` had its own support for atomic row > insertions and changes. The following methods existed in `HTable` and > aided the row updating process: > - > - ''0.1.3:'' > - <<BR>> {{{public synchronized long startUpdate(Text);}}} > - <<BR>> {{{public void put(long, Text, byte[]);}}} > - <<BR>> {{{public void put(long, Text, Writable);}}} > - <<BR>> {{{public void delete(long, Text);}}} > - <<BR>> {{{public synchronized void checkUpdateInProgress();}}} > - <<BR>> {{{public synchronized void abort(long);}}} > - <<BR>> {{{public synchronized void commit(long, long);}}} > - <<BR>> {{{public void commit(long);}}} > - > - `startUpdate(Text)` was used to start an atomic row update on the passed > row name, and a "lock id" (`long`) was returned to identify the update. > `put(...)` and `delete(...)` could be called using the lock id, and any > changes made with that lock id could be aborted or committed. > - > - HBase 0.2 has completely changed the way in which atomic row updates > take place. To update a row, the user first creates a `BatchUpdate` > object. `put(...)` and `delete(...)` operations are applied to the > `BatchUpdate`, not the `HTable`. Once finished, the user commits the > `BatchUpdate` with one of the following new `HTable` methods: > - > - ''0.2:'' > - <<BR>> {{{public synchronized void commit(BatchUpdate);}}} > - <<BR>> {{{public synchronized void commit(List<BatchUpdate>);}}} > - > - Aside from the transition from Text toward `byte[]` and the addition of > the `BatchUpdate` structure, `HTable` has experienced a number of other API > changes: > - > - * In 0.1.3, package-private `getRegionLocation(...)` took parameters > of either `(Text)` or `(Text, boolean)`. In 0.2, `getRegionLocation(...)` > has become public and only accepts parameters of either `(Text)`, > `(String)`, or `(byte[])`; the boolean "reload" option no longer exists. > - * In 0.1.3, the `HTable` constructor took parameters of either > `(HBaseConfiguration, Text)`. In 0.2, the `HBaseConfiguration` parameter > has become optional and as such there are now 6 different constructors > (with or without the `HBaseConfiguration` parameter, and with the `Text` > parameter varying as either `Text`, `String`, or `byte[]`). > - * `public HTableDescriptor getMetadata()` has been replaced in 0.2 by > `public HTableDescriptor getTableDescriptor()`; `getMetadata()` still > exists in 0.2, although it is marked as deprecated. Additionally, both > `getTableDescriptor()` and `getMetadata()` now return > `UnmodifyableHTableDescriptor` (new to 0.2, package > `org.apache.hadoop.hbase.client`, a subclass of `HTableDescriptor`), > although the return type of both methods is still `HTableDescriptor`. > - * In 0.1.3, all `get(...)` methods had a return type of `byte[]`. In > 0.2, these methods now return a `Cell` (new to 0.2, package ` > org.apache.hadoop.hbase.io`). > - * In 0.1.3, all `getRow(...)` methods had a return type of > `SortedMap<Text, byte[]>`. In 0.2, these methods now return a `RowResult` > (new to 0.2, package `org.apache.hadoop.hbase.io`). > - * The methods `obtainScanner(...)` from 0.1.3 have been renamed > `getScanner(...)` in 0.2. Moreover, `getScanner(...)` has a return type > of `Scanner` (new to 0.2, package `org.apache.hadoop.hbase.client`), > whereas `obtainScanner(...)` had a return type of `HScannerInterface` (a > class that no longer exists in 0.2). > - * In 0.1.3, `deteleFamily(...)` took parameters of either `(Text, Text, > long)` or `(Text, Text)`. In 0.2, `deleteFamily(...)` only accepts > parameters of either `(Text, Text, long)`, `(String, String, long)`, or > `(byte[], byte[], long)`; the long "timestamp" must be included as a > parameter. > - * The `HTable` subclass `ServerCallable<T>` from 0.1.3 has been moved > to its own separate class in 0.2, located in package > `org.apache.hadoop.hbase.client`. > - * The method `getRegionServerWithRetries(ServerCallable<T>)` from 0.1.3 > has been moved to the `HConnection` interface in 0.2. > - > - Finally, the following methods have been added to `HTable` in HBase 0.2: > - > - ''0.2:'' > - <<BR>> {{{public static boolean isTableEnabled(Text);}}} > - <<BR>> {{{public static boolean isTableEnabled(String);}}} > - <<BR>> {{{public static boolean isTableEnabled(byte[]);}}} > - <<BR>> {{{public static boolean isTableEnabled(HBaseConfiguration, > Text);}}} > - <<BR>> {{{public static boolean isTableEnabled(HBaseConfiguration, > String);}}} > - <<BR>> {{{public static boolean isTableEnabled(HBaseConfiguration, > byte[]);}}} > - > - Once again, for greater detail on API changes to `HBaseAdmin`, `HTable`, > and all classes new to HBase 0.2, please refer to the [HBase 0.2 API]. > - > -- *Regards,* *Sanju Reddy* *+91 8977977443*
