Accumulo++

A C++ library for Apache Accumulo. The API is incomplete thus far but provides enough of the very basic calls through the proxy API to exemplify what the full solution may look like. If you are interested in contributing, please don't hesitate to contact Corey Nolet ([email protected])

Why a C++ Library for Accumulo?

Simple- When I'm running logic in InfoSphere Streams, I'd like to talk to Accumulo in C/C++. If I'm running code that needs to utilize CUDA and the GPU, I'd like to stay in C/C++ also. In Accumulo 1.5, we were given an Apache Thrift-based proxy that allows us to generate clients in differing languages. This is one such client which has been augmented to look as close as possible to the Java-based API that we've all come to know and love.

Requirements

1. A running Accumulo cluster
2. The new Accumulo Thrift Proxy server (1.6 included in this codebase)
3. Thrift C++ library installed (http://thrift.apache.org/docs/install/)

Quick Start

1. You'll need to run the Accumulo Thrift Proxy server. A jar is packaged with this codebase in order to get this started quickly. Locate the server/proxy.properties file and fill in the necessary fields. When you are done, start up the server by running the following:

./server/runProxy.sh 1.5

2. Build the example programs:

make

3. Create an example table using the CreateTable example program

./target/CreateTableExample.o localhost 42424 root secret testTable

4. Run the BatchWriter example program to insert some rows into Accumulo:

./target/BatchWriterExample.o localhost 42424 root secret testTable row1 col1 qual6 U val

5. Run the Scanner example program to read rows from Accumulo:

./target/ScannerExample.o localhost 42424 root secret testTable A z

Code Samples

TableOperations Sample

try {
	Conector connector("localhost", 42424, "root", "secret");
	connector.tableOperations().createTable("testTable");
	connector.tableOperations().compactTable("testTable");
	connector.close();

} catch(AccumuloSecurityException &e) {
	cout << "There was a problem with the given credentials.\n";

} catch(TableNotFoundException &e) {
	cout << "The specified table was not found.\n";
}

BatchWriter Sample

try {
	Connector connector("localhost", 42424, "root", "secret");
	BatchWriter writer = connector.createBatchWriter("testTable", 500000, 10000, 10000, 2);

	Mutation mutation("rowId");
	mutation.put("colFam", "colQual", "colVis", 500000, "val");

	writer.addMutation(mutation);
	writer.flush();
	writer.close();
	
	connector.close();

} catch(AccumuloSecurityException &e) {
	cout << "There was a problem with the given credentials.\n";

} catch(TException &e) {
	cout << "An error occurred: the mutation was not written to the table.\n";
}

Scanner Sample

try {
	Connector connector("localhost", 42424, "root", "secret");

	Authorizations auths("A,B");
	Scanner scanner = connector.createScanner("testTable", auths);

	// Set up the range
	Key start("A");
	Key stop("z");
	Range range(start, stop);

	scanner.setRange(range);
	scanner.fetchColumn("department", "1");

	ScannerIterator itr = scanner.iterator();
	
	while(itr.hasNext()) {
		KeyValue kv = itr.next();

		cout << kv.getKey().getRow() << " " << kv.getKey().getColFamily() << ":" 
				 << kv.getKey().getColQualifier() << " [" << kv.getKey().getColVisibility() 
				 << "] " << kv.getKey().getTimestamp() << "\t" << kv.getValue() << "\n";

	}
	
	itr.close();
	connector.close();

} catch(AccumuloSecurityException &e) {
	cout << "There was a problem with the given credentials.\n";

} catch(TableNotFoundException &e) {
	cout << "The specified table was not found.\n";
}

BatchScanner Example

try {
	Connector connector("localhost", 42424, "root", "secret");

	Authorizations auths("A,B");	
	BatchScanner scanner = connector.createBatchScanner("testTable", auths, 5);
	
	// construct ranges
	Range range1(new Key("A"), new Key("Z");
	Range range2(new Key("a"), new Key("z");
	
	vector<Range> ranges;
	ranges.push_back(range1);
	ranges.push_back(range2);
	
	scanner.setRanges(ranges);
	scanner.fetchColumn("department", "1");
	
	BatchScannerIterator itr = scanner.iterator();
	
	while(itr.hasNext()) {

		KeyValue kv = itr.next();

		cout << kv.getKey().getRow() << " " << kv.getKey().getColFamily() << ":" 
			 << kv.getKey().getColQualifier() << " [" << kv.getKey().getColVisibility() 
			 << "] " << kv.getKey().getTimestamp() << "\t" << kv.getValue() << "\n";

	}
	
	itr.close();
	connector.close();
	
} catch(AccumuloSecurityException &e) {
	cout << "There was a problem with the given credentials.\n";

} catch(TableNotFoundException &e) {
	cout << "The specified table was not found.\n";
}