IO Error: Too many open files

[tuanchauict]

This is my code:

public long findMiss(int number) {
    long t0 = System.nanoTime();
    DB db = null;
    try {
        db = DBFactory.open(context, kryo);

        for (int i = 0; i < number; i++) {
            String key = "simple:" + (i + 100000); //for sure the key does not exist.
            Log.w("findMiss", i + " : " + key);
            try {
                if (db.exists(key)) {
                    db.getObject(key, SimpleModel.class);
                }
            } catch (SnappydbException e) {
                e.printStackTrace();
                break; //debug
            }
        }

        db.close();
    } catch (SnappydbException e) {
        e.printStackTrace();
        if (db != null) {
            try {
                db.close();
            } catch (SnappydbException ee) {
                ee.printStackTrace();
            }
        }
    }

    return System.nanoTime() - t0;
}

The result is:

W/findMiss﹕ 0 : simple:100000
W/findMiss﹕ 1 : simple:100001
W/findMiss﹕ 2 : simple:100002
W/findMiss﹕ 3 : simple:100003
W/System.err﹕ com.snappydb.SnappydbException: Failed to check if a key exists: IO error: /data/data/com.example.tuanchauict.nosqlbenchmark/files/snappydb/096870.ldb: Too many open files
W/System.err﹕ at com.snappydb.internal.DBImpl.__exists(Native Method)
W/System.err﹕ at com.snappydb.internal.DBImpl.exists(DBImpl.java:400)
W/System.err﹕ at com.example.tuanchauict.nosqlbenchmark.snappy.SimpleSnappyBenchmark.findMiss(SimpleSnappyBenchmark.java:95)
W/System.err﹕ at com.example.tuanchauict.nosqlbenchmark.MainActivity$1.run(MainActivity.java:52)
W/System.err﹕ at java.lang.Thread.run(Thread.java:818)

Since then, the code run below mentioned code throw the IO error. The for loop sometime runs to i = 3 sometime just 2, and even 4,...

Above findMiss code, I run findReach and it's okay:

public long findReach(int number) {
    long t0 = System.nanoTime();
    DB db = null;
    try {
        db = DBFactory.open(context, kryo);

        for (int i = 0; i < number; i++) {
            String key = "simple:" + (100 + i % 500);
            Log.w("findReach", i + " : " + key);
            if (db.exists(key))
                db.getObject(key, SimpleModel.class);
        }

        db.close();

    } catch (SnappydbException e) {
        e.printStackTrace();
        if (db != null) {
            try {
                db.close();
            } catch (SnappydbException ee) {
            }
        }
    }

    return System.nanoTime() - t0;
}