-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/816/
-----------------------------------------------------------
(Updated 2010-09-10 17:29:57.718053)
Review request for hbase, Andrew Purtell and Jonathan Gray.
Summary
-------
This is really two separate patches in one, though with some overlapping
changes. If necessary I can split them apart for separate review. Please let
me know if that would make review easier.
Part 1:
==============
Port over of HADOOP-6422 to the HBase RPC code. The goal of this change is to
allow alternate RPC client/server implementations to be enabled through a
simple configuration change. Ultimately I would like to use this to allow
secure RPC to be enabled through configuration, while not blocking normal
(current) RPC operation on non-secure Hadoop versions.
This portion of the patch abstracts out two interfaces from the RPC code:
RpcEngine: HBaseRPC uses this to obtain proxy instances for client calls and
server instances for HMaster and HRegionServer
RpcServer: this allows differing RPC server implementations, breaking the
dependency on HBaseServer
The bulk of the current code from HBaseRPC is moved into WritableRpcEngine and
is unchanged other than the interface requirements. So the current call path
remains the same, other than the HBaseRPC.getProtocolEngine() abstraction.
Part 2:
===============
The remaining changes provide server-side hooks for registering new RPC
protocols/handlers (per-region to support coprocessors), and client side hooks
to support dynamic execution of the registered protocols.
The new RPC protocol actions are constrained to
org.apache.hadoop.hbase.ipc.CoprocessorProtocol implementations (which extends
VersionedProtocol) to prevent arbitrary execution of methods against
HMasterInterface, HRegionInterface, etc.
For protocol handler registration, HRegionServer provides a new method:
public <T extends CoprocessorProtocol> boolean registerProtocol(
byte[] region, Class<T> protocol, T handler)
which builds a Map of region name to protocol instances for dispatching client
calls.
Client invocations are performed through HTable, which adds the following
methods:
public <T extends CoprocessorProtocol> T proxy(Class<T> protocol, Row row)
This directly returns a proxy instance to the CoprocessorProtocol
implementation registered for the region serving row "row". Any method calls
will be proxied to the region's server and invoked using the map of registered
region name -> handler instances.
Calls directed against multiple rows are a bit more complicated. They are
supported with the methods:
public <T extends CoprocessorProtocol, R> void exec(
Class<T> protocol, List<? extends Row> rows,
BatchCall<T,R> callable, BatchCallback<R> callback)
public <T extends CoprocessorProtocol, R> void exec(
Class<T> protocol, RowRange range,
BatchCall<T,R> callable, BatchCallback<R> callback)
where BatchCall and BatchCallback are simple interfaces defining the methods to
be called and a callback instance to be invoked for each result.
For the sample CoprocessorProtocol interface:
interface PingProtocol extends CoprocessorProtocol {
public String ping();
public String hello(String name);
}
a client invocation might look like:
final Map<byte[],R> results = new TreeMap<byte[],R>(...)
List<Row> rows = ...
table.exec(PingProtocol.class, rows,
new HTable.BatchCall<PingProtocol,String>() {
public String call(PingProtocol instance) {
return instance.ping();
}
},
new BatchCallback<R>(){
public void update(byte[] region, byte[] row, R value) {
results.put(region, value);
}
});
The BatchCall.call() method will be invoked for each row in the passed in list,
and the BatchCallback.update() method will be invoked for each return value.
However, currently the PingProtocol.ping() invocation will result in a separate
RPC call per row, which is less that ideal.
Support is in place to make use of the HRegionServer.multi() invocations for
batched RPC (see the org.apache.hadoop.hbase.client.Exec class), but this does
not mesh well with the current client-side interface.
In addition to standard code review, I'd appreciate any thoughts on the client
interactions in particular, and whether they would meet some of the anticipated
uses of coprocessors.
This addresses bugs HBASE-2002 and HBASE-2321.
http://issues.apache.org/jira/browse/HBASE-2002
http://issues.apache.org/jira/browse/HBASE-2321
Diffs (updated)
-----
src/main/java/org/apache/hadoop/hbase/client/Action.java 556ea81
src/main/java/org/apache/hadoop/hbase/client/Exec.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/client/ExecResult.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/client/HConnection.java 65f7618
src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java f1fa836
src/main/java/org/apache/hadoop/hbase/client/HTable.java 0dbf263
src/main/java/org/apache/hadoop/hbase/client/MultiAction.java dc0e203
src/main/java/org/apache/hadoop/hbase/client/MultiResponse.java 60008b1
src/main/java/org/apache/hadoop/hbase/client/RowRange.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/client/Scan.java 29b3cb0
src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java 83f623d
src/main/java/org/apache/hadoop/hbase/ipc/ConnectionHeader.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/ipc/CoprocessorProtocol.java
PRE-CREATION
src/main/java/org/apache/hadoop/hbase/ipc/ExecRPCInvoker.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/ipc/HBaseClient.java 2b5eeb6
src/main/java/org/apache/hadoop/hbase/ipc/HBaseRPC.java 134288b
src/main/java/org/apache/hadoop/hbase/ipc/HBaseServer.java d3c6c21
src/main/java/org/apache/hadoop/hbase/ipc/HRegionInterface.java c3e24d9
src/main/java/org/apache/hadoop/hbase/ipc/RpcEngine.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/ipc/WritableRpcEngine.java PRE-CREATION
src/main/java/org/apache/hadoop/hbase/master/HMaster.java adc6292
src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java 1e046f9
src/main/resources/hbase-default.xml 2fcfcc8
src/test/java/org/apache/hadoop/hbase/regionserver/TestServerCustomProtocol.java
PRE-CREATION
Diff: http://review.cloudera.org/r/816/diff
Testing
-------
Thanks,
Gary
