Examples with EvictionThread org.apache.hadoop.hbase.io.hfile.LruBlockCache.EvictionThread used on opensource projects

Example 1 with EvictionThread

use of org.apache.hadoop.hbase.io.hfile.LruBlockCache.EvictionThread in project hbase by apache.

the class TestLruBlockCache method testCacheEvictionThreadSafe.

@Test
public void testCacheEvictionThreadSafe() throws Exception {
    long maxSize = 100000;
    int numBlocks = 9;
    int testRuns = 10;
    final long blockSize = calculateBlockSizeDefault(maxSize, numBlocks);
    assertTrue("calculateBlockSize appears broken.", blockSize * numBlocks <= maxSize);
    final LruBlockCache cache = new LruBlockCache(maxSize, blockSize);
    EvictionThread evictionThread = cache.getEvictionThread();
    assertTrue(evictionThread != null);
    while (!evictionThread.isEnteringRun()) {
        Thread.sleep(1);
    }
    final String hfileName = "hfile";
    int threads = 10;
    final int blocksPerThread = 5 * numBlocks;
    for (int run = 0; run != testRuns; ++run) {
        final AtomicInteger blockCount = new AtomicInteger(0);
        ExecutorService service = Executors.newFixedThreadPool(threads);
        for (int i = 0; i != threads; ++i) {
            service.execute(new Runnable() {

                @Override
                public void run() {
                    for (int blockIndex = 0; blockIndex < blocksPerThread || (!cache.isEvictionInProgress()); ++blockIndex) {
                        CachedItem block = new CachedItem(hfileName, (int) blockSize, blockCount.getAndIncrement());
                        boolean inMemory = Math.random() > 0.5;
                        cache.cacheBlock(block.cacheKey, block, inMemory, false);
                    }
                    cache.evictBlocksByHfileName(hfileName);
                }
            });
        }
        service.shutdown();
        // The test may fail here if the evict thread frees the blocks too fast
        service.awaitTermination(10, TimeUnit.MINUTES);
        assertEquals(0, cache.getBlockCount());
        assertEquals(cache.getOverhead(), cache.getCurrentSize());
    }
}

Example 2 with EvictionThread

use of org.apache.hadoop.hbase.io.hfile.LruBlockCache.EvictionThread in project hbase by apache.

the class TestLruBlockCache method testBackgroundEvictionThread.

@Test
public void testBackgroundEvictionThread() throws Exception {
    long maxSize = 100000;
    int numBlocks = 9;
    long blockSize = calculateBlockSizeDefault(maxSize, numBlocks);
    assertTrue("calculateBlockSize appears broken.", blockSize * numBlocks <= maxSize);
    LruBlockCache cache = new LruBlockCache(maxSize, blockSize);
    EvictionThread evictionThread = cache.getEvictionThread();
    assertTrue(evictionThread != null);
    CachedItem[] blocks = generateFixedBlocks(numBlocks + 1, blockSize, "block");
    // Make sure eviction thread has entered run method
    while (!evictionThread.isEnteringRun()) {
        Thread.sleep(1);
    }
    // Add all the blocks
    for (CachedItem block : blocks) {
        cache.cacheBlock(block.cacheKey, block);
    }
    // wait until at least one eviction has run
    int n = 0;
    while (cache.getStats().getEvictionCount() == 0) {
        Thread.sleep(200);
        assertTrue("Eviction never happened.", n++ < 20);
    }
    // let cache stabilize
    // On some systems, the cache will run multiple evictions before it attains
    // steady-state. For instance, after populating the cache with 10 blocks,
    // the first eviction evicts a single block and then a second eviction
    // evicts another. I think this is due to the delta between minSize and
    // acceptableSize, combined with variance between object overhead on
    // different environments.
    n = 0;
    for (long prevCnt = 0, /* < number of blocks added */
    curCnt = cache.getBlockCount(); prevCnt != curCnt; prevCnt = curCnt, curCnt = cache.getBlockCount()) {
        Thread.sleep(200);
        assertTrue("Cache never stabilized.", n++ < 20);
    }
    long evictionCount = cache.getStats().getEvictionCount();
    assertTrue(evictionCount >= 1);
    System.out.println("Background Evictions run: " + evictionCount);
}