i have a huge memory problem in my app. i am using google map api v2 with ClusterManager and custom markers. i supply an image via call to markerOptions.icon(BitmapDescriptorFactory.fromBitmap(bitmap)); for each marker based on its category. the problem is: after several screen rotations my app crashes because of OOM error:
05-14 11:04:12.692  14020-30201/rokask.rideabike E/art﹕ Throwing OutOfMemoryError "Failed to allocate a 4194316 byte allocation with 1627608 free bytes and 1589KB until OOM"
05-14 11:04:12.722  14020-30201/rokask.rideabike E/AndroidRuntime﹕ FATAL EXCEPTION: GLThread 19179
Process: rokask.rideabike, PID: 14020
java.lang.OutOfMemoryError: Failed to allocate a 4194316 byte allocation with 1627608 free bytes and 1589KB until OOM
        at dalvik.system.VMRuntime.newNonMovableArray(Native Method)
        at android.graphics.Bitmap.nativeCreate(Native Method)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:939)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:912)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:879)
        at com.google.maps.api.android.lib6.gmm6.n.c.i.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.c.l.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.c.l.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.c.l.b(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.c.b.ak.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.c.b.as.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.x.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.l.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.l.b(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.cv.f(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.n.cv.run(Unknown Source)
i have a LruCache object with my Bitmaps, it means that i do not recreate them, but reuse them. i can clearly see that every Bitmap object is taken from the cache, not from elsewhere. However, if the Bitmap is not in the cache yet (first time loading) i load it from my app's internal storage, but it only happnes when the Bitmap is laoded the first time. i keep the instance of the LruCache in a retained Fragment instance and pass it to my custom DefaultClusterRenderer<MyObject> object everytime the Activity is recreated and map needs to be redrawn.
this is my DefaultClusterRenderer<MyItem> extension:
public class DotRenderer extends DefaultClusterRenderer<Dot> {
private final String internalStorageDir;
private final LruCache<String, Bitmap> lruCache;
public DotRenderer(Context context, GoogleMap googleMap, ClusterManager<Dot> clusterManager,
                   LruCache<String, Bitmap> lruCache, String internalStorageDir)
{
    super(context, googleMap, clusterManager);
    //this.bitmaps = bitmaps;
    this.internalStorageDir = internalStorageDir;
    this.lruCache = lruCache;
}
@Override
protected void onBeforeClusterItemRendered(Dot mapObject, MarkerOptions markerOptions) {
    markerOptions.title(mapObject.getTitle());
    String id = Integer.toString(mapObject.getTypeId());
    //
    Bitmap bitmap = getBitmapFromMemCache(id);
    if (bitmap == null) {
        Log.d(MainActivity.LOG_TAG, "reading bitmap from storage.");
        Map.Entry<String, Bitmap> bitmapEntry
                = BitmapManager.getBitmapFromStorage(internalStorageDir, id);
        if (bitmapEntry != null) {
            markerOptions.icon(BitmapDescriptorFactory.fromBitmap(bitmapEntry.getValue()));
            addBitmapToMemCache(id, bitmapEntry.getValue());
        }
    } else {
        Log.d(MainActivity.LOG_TAG, "reading bitmap from cache.");
        markerOptions.icon(BitmapDescriptorFactory.fromBitmap(bitmap));
    }
}
private void addBitmapToMemCache(String key, Bitmap bitmap) {
    if (getBitmapFromMemCache(key) == null) {
        lruCache.put(key, bitmap);
    }
}
private Bitmap getBitmapFromMemCache(String key) {
    return lruCache.get(key);
}
}
this is the code inside my Activity where i start loading the map (this code is executed everytime screen orientation changes):
    ClusterManager<Dot> clusterManager = new ClusterManager<>(this, googleMap);
    clusterManager.setOnClusterItemInfoWindowClickListener(
            new ClusterManager.OnClusterItemInfoWindowClickListener<Dot>() {
                @Override
                public void onClusterItemInfoWindowClick(Dot dot) {
                    int id = dot.getId();
                    String title = dot.getTitle();
                    Log.d(LOG_TAG, "clicked marker with id " + id
                            + " and title " + title + ".");
                    Intent infoWindowActivityIntent =
                            new Intent(MainActivity.this, InfoWindowActivity.class);
                    infoWindowActivityIntent.putExtra("dotId", id);
                    infoWindowActivityIntent.putExtra("dotTitle", title);
                    startActivity(infoWindowActivityIntent);
                }
            });
    googleMap.setOnCameraChangeListener(clusterManager);
    googleMap.setOnInfoWindowClickListener(clusterManager);
    DotRenderer dotRenderer =
            new DotRenderer(getApplicationContext(), googleMap, clusterManager,
                    lruCache, this.getFilesDir().toString());
    clusterManager.setRenderer(dotRenderer);
the memory keeps increasing with every screen rotation, the more i zoom in the map (the more markers are shown) the more amount of memory is added to my app's heap when i rotate the screen until application crashes.
sometimes the error is not like above, but shows that OOM happened at this line in my DefaultClusterRenderer<MyItam> extension markerOptions.icon(BitmapDescriptorFactory.fromBitmap(bitmap));.
if i disable custom marker icon (remove all the Bitmap related code) the memory problem vanishes. please help me to find what causes this OOM to appear.