List of usage examples for java.util Random getClass
@HotSpotIntrinsicCandidate public final native Class<?> getClass();
From source file:net.lizalab.util.RdRandRandomTest.java
/** * Runs the Monte Carlo Pi approximation test for the specified * instance of Random./* w w w .j a v a 2 s. co m*/ * @param random The RNG instance to test. * @param doAssert Flag to indicate whether result should be asserted or simply logged. */ private void monteCarloPiTest(Random random, boolean doAssert) { final String methodName = "monteCarloPiTest : "; int inRandCircle = 0; // xr and yr will be the random point // zr will be the calculated distance to the center double xr, yr, zr; long start = System.currentTimeMillis(); for (int i = 0; i < numPoints; i++) { xr = random.nextDouble(); yr = random.nextDouble(); zr = (xr * xr) + (yr * yr); if (zr <= 1.0) { inRandCircle++; } } long end = System.currentTimeMillis(); LOGGER.info("{} Time: {}ms", methodName, end - start); // calculate the Pi approximations double randomPi = (double) inRandCircle / numPoints * 4.0; // calculate the difference and % error double diff = (randomPi - Math.PI); double randomError = diff / Math.PI * 100; LOGGER.info("{} Pi Approximation: {}, Diff: {}, Error %: {}", methodName, randomPi, diff, randomError); BigDecimal randomPiBD = new BigDecimal(randomPi); randomPiBD = randomPiBD.setScale(precision - 1, RoundingMode.DOWN); // Verify result. boolean result = randomPiBD.compareTo(pi) == 0; String msg = "Pi approximation not sufficiently precise for " + random.getClass(); if (doAssert) { assertTrue(msg, result); } else { if (!result) { LOGGER.warn("{} {}", methodName, msg); } } }
From source file:org.apache.hadoop.dfs.ClusterTestDFS.java
/** * Pseudo Distributed FS Testing./*from w w w . java 2s.c o m*/ * Do one test cycle with given parameters. * * @param nBytes number of bytes to write to each file. * @param numFiles number of files to create. * @param blockSize block size to use for this test cycle. * @param initialDNcount number of datanodes to create * @throws Exception */ public void testFsPseudoDistributed(long nBytes, int numFiles, int blockSize, int initialDNcount) throws Exception { long startTime = System.currentTimeMillis(); int bufferSize = Math.min(BUFFER_SIZE, blockSize); boolean checkDataDirsEmpty = false; int iDatanodeClosed = 0; Random randomDataGenerator = makeRandomDataGenerator(); final int currentTestCycleNumber = testCycleNumber; msg("using randomDataGenerator=" + randomDataGenerator.getClass().getName()); // // modify config for test // // set given config param to override other config settings conf.setInt("test.dfs.block_size", blockSize); // verify that config changed assertTrue(blockSize == conf.getInt("test.dfs.block_size", 2)); // 2 is an intentional obviously-wrong block size // downsize for testing (just to save resources) conf.setInt("dfs.namenode.handler.count", 3); if (false) { // use MersenneTwister, if present conf.set("hadoop.random.class", "org.apache.hadoop.util.MersenneTwister"); } conf.setLong("dfs.blockreport.intervalMsec", 50 * 1000L); conf.setLong("dfs.datanode.startupMsec", 15 * 1000L); String nameFSDir = baseDirSpecified + "/name"; msg("----Start Test Cycle=" + currentTestCycleNumber + " test.dfs.block_size=" + blockSize + " nBytes=" + nBytes + " numFiles=" + numFiles + " initialDNcount=" + initialDNcount); // // start a NameNode int nameNodePort = 9000 + testCycleNumber++; // ToDo: settable base port String nameNodeSocketAddr = "localhost:" + nameNodePort; conf.set("dfs.name.dir", nameFSDir); NameNode nameNodeDaemon = new NameNode(nameNodeSocketAddr, conf); DFSClient dfsClient = null; try { // // start some DataNodes // ArrayList<DataNode> listOfDataNodeDaemons = new ArrayList<DataNode>(); FileSystem.setDefaultUri(conf, "hdfs://" + nameNodeSocketAddr); for (int i = 0; i < initialDNcount; i++) { // uniquely config real fs path for data storage for this datanode String dataDirs[] = new String[1]; dataDirs[0] = baseDirSpecified + "/datanode" + i; conf.set("dfs.data.dir", dataDirs[0]); DataNode dn = DataNode.makeInstance(dataDirs, conf); if (dn != null) { listOfDataNodeDaemons.add(dn); (new Thread(dn, "DataNode" + i + ": " + dataDirs[0])).start(); } } try { assertTrue("insufficient datanodes for test to continue", (listOfDataNodeDaemons.size() >= 2)); // // wait for datanodes to report in awaitQuiescence(); // act as if namenode is a remote process dfsClient = new DFSClient(new InetSocketAddress("localhost", nameNodePort), conf); // // write nBytes of data using randomDataGenerator to numFiles // ArrayList<UTF8> testfilesList = new ArrayList<UTF8>(); byte[] buffer = new byte[bufferSize]; UTF8 testFileName = null; for (int iFileNumber = 0; iFileNumber < numFiles; iFileNumber++) { testFileName = new UTF8("/f" + iFileNumber); testfilesList.add(testFileName); OutputStream nos = dfsClient.create(testFileName.toString(), false); try { for (long nBytesWritten = 0L; nBytesWritten < nBytes; nBytesWritten += buffer.length) { if ((nBytesWritten + buffer.length) > nBytes) { // calculate byte count needed to exactly hit nBytes in length // to keep randomDataGenerator in sync during the verify step int pb = (int) (nBytes - nBytesWritten); byte[] bufferPartial = new byte[pb]; randomDataGenerator.nextBytes(bufferPartial); nos.write(bufferPartial); } else { randomDataGenerator.nextBytes(buffer); nos.write(buffer); } } } finally { nos.flush(); nos.close(); } } // // No need to wait for blocks to be replicated because replication // is supposed to be complete when the file is closed. // // // take one datanode down iDatanodeClosed = currentTestCycleNumber % listOfDataNodeDaemons.size(); DataNode dn = (DataNode) listOfDataNodeDaemons.get(iDatanodeClosed); msg("shutdown datanode daemon " + iDatanodeClosed + " dn=" + dn.data); try { dn.shutdown(); } catch (Exception e) { msg("ignoring datanode shutdown exception=" + e); } // // verify data against a "rewound" randomDataGenerator // that all of the data is intact long lastLong = randomDataGenerator.nextLong(); randomDataGenerator = makeRandomDataGenerator(); // restart (make new) PRNG ListIterator li = testfilesList.listIterator(); while (li.hasNext()) { testFileName = (UTF8) li.next(); FSInputStream nis = dfsClient.open(testFileName.toString()); byte[] bufferGolden = new byte[bufferSize]; int m = 42; try { while (m != -1) { m = nis.read(buffer); if (m == buffer.length) { randomDataGenerator.nextBytes(bufferGolden); assertBytesEqual(buffer, bufferGolden, buffer.length); } else if (m > 0) { byte[] bufferGoldenPartial = new byte[m]; randomDataGenerator.nextBytes(bufferGoldenPartial); assertBytesEqual(buffer, bufferGoldenPartial, bufferGoldenPartial.length); } } } finally { nis.close(); } } // verify last randomDataGenerator rand val to ensure last file length was checked long lastLongAgain = randomDataGenerator.nextLong(); assertEquals(lastLong, lastLongAgain); msg("Finished validating all file contents"); // // now delete all the created files msg("Delete all random test files under DFS via remaining datanodes"); li = testfilesList.listIterator(); while (li.hasNext()) { testFileName = (UTF8) li.next(); assertTrue(dfsClient.delete(testFileName.toString(), true)); } // // wait for delete to be propagated // (unlike writing files, delete is lazy) msg("Test thread sleeping while datanodes propagate delete..."); awaitQuiescence(); msg("Test thread awakens to verify file contents"); // // check that the datanode's block directory is empty // (except for datanode that had forced shutdown) checkDataDirsEmpty = true; // do it during finally clause } catch (AssertionFailedError afe) { throw afe; } catch (Throwable t) { msg("Unexpected exception_b: " + t); t.printStackTrace(); } finally { // // shut down datanode daemons (this takes advantage of being same-process) msg("begin shutdown of all datanode daemons for test cycle " + currentTestCycleNumber); for (int i = 0; i < listOfDataNodeDaemons.size(); i++) { DataNode dataNode = (DataNode) listOfDataNodeDaemons.get(i); if (i != iDatanodeClosed) { try { if (checkDataDirsEmpty) { assertNoBlocks(dataNode); } dataNode.shutdown(); } catch (Exception e) { msg("ignoring exception during (all) datanode shutdown, e=" + e); } } } } msg("finished shutdown of all datanode daemons for test cycle " + currentTestCycleNumber); if (dfsClient != null) { try { msg("close down subthreads of DFSClient"); dfsClient.close(); } catch (Exception ignored) { } msg("finished close down of DFSClient"); } } catch (AssertionFailedError afe) { throw afe; } catch (Throwable t) { msg("Unexpected exception_a: " + t); t.printStackTrace(); } finally { // shut down namenode daemon (this takes advantage of being same-process) msg("begin shutdown of namenode daemon for test cycle " + currentTestCycleNumber); try { nameNodeDaemon.stop(); } catch (Exception e) { msg("ignoring namenode shutdown exception=" + e); } msg("finished shutdown of namenode daemon for test cycle " + currentTestCycleNumber); } msg("test cycle " + currentTestCycleNumber + " elapsed time=" + (System.currentTimeMillis() - startTime) / 1000. + "sec"); msg("threads still running (look for stragglers): "); msg(summarizeThreadGroup()); }