Specifically I'd like my parameter store worker to always be invoked on the HEAD node, and not on any of the workers. This way I can optimize the resource configuration. Currently the parameter store task seems to get started on a random server, even if it called first, and even if it is followed by a ray.get()
Maybe it's possible to do something like:
ps = ParameterStore.remote(onHead=True)?
You can start the "head" node with an extra custom resource and then you can make the parameter store actor require that custom resource. For example, start the head node with:
ray start --head --resources='{"PSResource": 1}'
Then you can declare the parameter store actor class with
#ray.remote(resources={"PSResource": 1})
class ParameterStore(object):
pass
ps = ParameterStore.remote()
You can also declare the parameter store actor regularly and change the way you invoke it. E.g.,
#ray.remote
class ParameterStore(object):
pass
ps = ParameterStore._remote(args=[], resources={"PSResource": 1})
You can read more about resources in Ray at https://ray.readthedocs.io/en/latest/resources.html.
Related
I've created a custom resource for creating a ThingType which is not yet implemented by AWS as simple CfnObjects. My code looks like this:
String physicalResIdThingType = "ThisISMyThing";
AwsCustomResource.Builder.create(this, "myThingType")
.onCreate(AwsSdkCall.builder()
.service("Iot")
.action("createThingType")
.physicalResourceId(PhysicalResourceId.of(physicalResIdThingType))
.parameters(new HashMap() {{
put("thingTypeName", "myThingType");
}})
.build())
.onDelete(AwsSdkCall.builder()
.service("Iot")
.action("deleteThingType")
.physicalResourceId(PhysicalResourceId.of(physicalResIdThingType))
.parameters(new HashMap() {{
put("thingTypeName", "myThingType");
}}).build()) .policy(AwsCustomResourcePolicy.fromSdkCalls(SdkCallsPolicyOptions.builder()
.resources(AwsCustomResourcePolicy.ANY_RESOURCE)
.build()))
.installLatestAwsSdk(false)
.resourceType(Consts.CUSTOM_RESOURCE_THING_TYPE)
.build();
It is creating well. but not allowing me to delete the thing type because I need first to deprecate it and then delete it.. In the console we need to wait even 5 minutes after deprecation for complete deletion.
My questions are:
Is it possible to override this deprecation ?
If not, Is it possible to do multiple AwsSdkCalls without writing my own lambda functions ?
If none from above, then maybe someone has an idea how can I use this simple solution of AwsCustomResource to delete my thing type?
I can only see one way to do it if you want the thing type to be deleted via cloudformation.
You can configure the timeout-in-minutes when call cloudformation crate-stack . This value should be above than 5 minutes + extra buffer for the other resources to be deleted.
When you receive a DELETE event in your custom resource, you can deprecate the thing type, wait 5min and call delete thing type.
I'm trying to do a project described also here: PacketQueue is 0
I've modified the UdpBasicApp.cc to suit my needs, and in the handleMessage() function I added a piece of code to retrieve the length of the ethernet queue of a router. However the value returned is always 0.
My .ned file regarding the queue of routers is this:
**.router*.eth[*].mac.queue.typename = "DropTailQueue"
**.router*.eth[*].mac.queue.packetCapacity = 51
The code added in the UdpBasicApp.cc file is this:
cModule *mod = getModuleByPath("router3.eth[*].mac.queue.");
queueing::PacketQueue *queue = check_and_cast<queueing::PacketQueue*>(mod);
int c = queue->getNumPackets();
So my question is this: is this the right way to create a queue in a router linked to other nodes with an ethernet link?
My doubt is that maybe packets don't pass through the specified interface, i.e. I've set the ini parameters for the wrong queue.
You are not creating that queue. It was already instantiated by the OMNeT++ kernel. You are just getting a reference to an already existing module with the getModuleByPath() call.
The router3.eth[*].mac.queue. module path is rather suspicious in that call. It is hard-coded in all of your application to get the queue length from router3 even if the app is installed in router1. i.e. you are trying to look at the queue length in a completely different node. Then, the eth[*] is wrong. As a router obviously contains more than one ethernet interface (otherwise it would not be a router), you must explicitly specify which interface you want to sepcify. You must not specify patterns in module path (i.e. eth[0] or something like that, with an exact index must be specified). And at this point, you have to answer the question which ethernet interface I'm interested in, and specify that index. Finally the . end the end is also invalid, so I believe, your code never executes, otherwise the check_and_cast part would have raised an error already.
If you wanted to reach the first enthern interface from an UDP app in the same node, you would use relative path, something like this: ^.eth[0].mac.queue
Finally, if you are unsure whether your model works correctly, why not start the model with Qtenv, and check whether the given module receives any packet? Like,, drill down in the model until the given queue is opened as a simple module (i.e. you see the empty inside of the queue module) and then tap the run/fast run until next event in this module. If the simulation does not stop, then that module indeed did not received any packets and your configuration is wrong.
I started to play around with caf and using it to represent a graph.
Since this graph is unidirected I can create the actors that I need and link them accordingly, but now I want to find a specific actor identified by it's name.
class node_actor : public event_based_actor{
std::string m_name;
...
};
int main(){
auto entry_actor = spawn<node_actor>();
// node_actor will spawn other actors with names
// like this: node_actor will spawn node1
// node1 will spwan node2
// node2 will spwan node3 and so on
// now I want to send a message to node2
scoped_actor self;
self->send(n2, 42});
...
}
What would be the best way to find n2?
Can this be handled by a group, broadcasting a message? E.g like this:
{
auto g = group::get("local", "Node events");
auto entry_actor = spawn_in_group<node_actor>(g);
// change all nodes to call spawn_in_group
scoped_actor self;
self->send(g, name, 42})
}
If so wouldn't that be much overhead, because all nodes must be checked if they match the message?
Or are there other ways that I did not find in the docs yet?
I think the group is a good idea because it also works distributed. You can have a better scalability by announcing each spawned actor to the group instead of broadcasting the messages.
Each actor that needs a name <-> actor mapping would then subscribe to the group (before you actually spawn your nodes). Whenever you spawn a new node, you send its name along with its handle to the group and each listener adds this mapping to its local state (or ignores the message if it is only interested in a few selected names).
In case you have a lot of actors that need the name mapping and you don't want to replicate the mapping many times, you could also use a single actor instead of a group that stores a map and can be queried by others whenever they need to resolve a name.
Your third option is to use the actor registry, but this will only work locally and only if you can use atom names. If this matches your use case, then you can register new actors via detail::singletons::get_actor_registry()->put_named(key, value); and retrieve them via detail::singletons::get_actor_registry()->get_named(key);. I usually don't recommend features from the detail namespace, but this particular feature will make its way to the public API in 0.15. By the way, you can create an atom_value dynamically, but you are of course limited to 10 characters and are only allowed to use alphanumeric characters.
Hope that helps.
I use Polymer.Templatizer to stamp templates of paper-input collections into a custom-element which has a listener 'change':'_doStuff'.
Basically when I stamp 20 paper-inputs via Polymer.dom(this).appendChild(template.root) a bunch of listeners are added , as you can see in the graph.
Then I call another function that goes through all of those elements and does Polymer.dom(paperInput.parentNode).removeChild(paperInput) and adds another set of inputs. But it just doesn't detach listeners on those for some reason and the heap is growing with every iteration...
The listener change on the host element, I believe, is neither detached.
What am I doing wrongly?
EDIT: I know what it is, it's not garbage collection problem, but Polymer creates anonymous Polymer.Base instances when templatizing and actually puts all template's children into those. of course the instances are not removed in any way. I wish I knew how to kill those not to reduce performance of the app. By defining custom elements instead? Looks like an overhead to me...
A way to free your memory could be to unlisten all of your listeners before you detach your elements, in order them to be unreferenced first. For example :
for (var i = 0; i < inputList.length; i++) {
this.unlisten(inputList[i], 'change', 'doStuff');
Polymer.dom(inputList[i].parentNode).removeChild(inputList[i]);
}
I have a List (e.g. the output of a database query) variable, which I use to create actors (they could be many and they are varied). I use the following code (in TestedActor preStart()), the actor qualified name is from the List variable as an example):
Class<?> classobject = Class.forName("com.java.anything.actor.MyActor"); //create class from name string
ActorRef actref = getContext().actorOf(Props.create(classobject), actorname); //creation
the code was tested:
#Test
public void testPreStart() throws Exception {
final Props props = Props.create(TestedActor.class);
final TestActorRef<TestedActor > ref = TestActorRef.create(system, props, "testA");
#SuppressWarnings("unused")
final TestedActor actor = ref.underlyingActor();
}
EDIT : it is working fine (contrary to the previous post, where I have seen a timeout error, it turned out as an unrelated alarm).
I have googled some posts related to this issue (e.g. suggesting the usage of newInstance), however I am still confused as these were superseded by mentioning it as a bad pattern. So, I am looking for a solution in java, which is also safe from the akka point of view (or the confirmation of the above pattern).
Maybe if you would write us why you need to create those actors this way it would help to find the solution.
Actually most people will tell you that using reflection is not the best idea. Sometimes it's the only option but you should avoid it.
Maybe this would be a solution for you:
Since actors are really cheap you can create all of them upfront. How many of them do you have?
Now the query could return you a path to the actor, not the class. Select it with actorSelection and send messages to it.
If your actors does a long running job you can use a router or if you want to a Proxy Actor that will spawn other actors as needed. Other option is to create futures from a single actor.
It really depends on the case, because you may need to create multiple execution context's not to starve any of the actors (of futures).