TaskExecutor | centralized asynchronous Task execution framework

Okay, so I find out the problem. I was using a solution for JUnit 4, not for the JUnit 5 library.

1. The extension I have created was right, whenever we use LiveData objects, we should update LiveData objects immediately.
2. How I was setting up the Coroutine scope for test cases, it was wrong. I was using a solution for JUnit 4 but I should modify the code to make the same but for JUnit5.

this looks like a simplified version of what the reactor-pool does, in essence. have you considered using that with eg. a maximum size of 1?

https://github.com/reactor/reactor-pool/

https://projectreactor.io/docs/pool/0.2.7/api/reactor/pool/Pool.html

The pool is probably overkill, because it has the overhead of having to deal with multiple resources on top of multiple competing borrowers like in your case, but maybe it could provide some inspiration for you to go further.

There are some partial answers on this issue from various places, here is what I think as a complete answer.

• Mongo clients use the hostnames listed in the replica set config, not the seed list

  Although the connection string is "mongodb://localhost:27017,localhost:27018,localhost:27019/?replicaSet=rs", mongo client does not connect to the members of the replica set with seed addresses localhost:27017 etc, instead the client connects to the members in the replica config set returned from the seed hosts, i.e., the ones in the rs.initiate call. This is why the error message is Error connecting to mongo1:27017 instead of Error connecting to localhost:27017.

• Container hostnames are not addressable outside the container network

  A mongo client inside the same container network as the mongo server containers can connect to the server via addresses like mongo1:27017; however, a client on the host, which is outside of the container network, can not resolve mongo1 to an IP. The typical solution for this problem is proxy, see Access docker container from host using containers name for details.

Because the problem involves docker networking and docker networking varies between Linux and Mac. The fixes are different on the two platforms.

The proxy fix (via 3rd party software or modifying /etc/hosts file) works fine but sometimes is not viable, e.g., running on remote CI hosts. A simple self-contained portable solution is to update the intiate_replia_set.sh script to initiate the replica set with member IPs instead of hostnames.

intiate_replia_set.sh

Short answer? Yes

On shutdown ( either by hitting by a request to the shutdown end point or by calling applicationcontext.close ) by default, Spring's TaskExecutor simply interrupts all running tasks.

Note that your threads must be in an interruptible state (e.g. sleep) to actually be interrupted.

In some cases you may want to wait for all running tasks to be complete.

calling setWaitForTasksToCompleteOnShutdown(true) simply prevents interrupting the running tasks on shutdown and ensures that both the currently executing tasks and queued up tasks are completed.

( I assume this is because they are non-daemon threads that prevent application exit. )

In short, the answer to your question is yes.

You can play with the following piece of code. When you change setWait from false to true, you will see that the application will not exit until the sleep is over. When you set it to false, the application will terminate immediately.

There are two key parameters here: the size of your worker threads pool and the size of your datatbase connection pool.

If each thread requests a database connection and you have more workers than available connections, then at some point worker threads will wait for connections to become available. This wait could timeout if no connections are released before the configured timeout value.

So you need to make sure you have enough connections for your worker threads, or increase the timeout in your connection pool.

The difficulty that you are having is getting a good mapping from the image in the ImageProxy to what is displayed by the PreviewView. Although this sounds easy, I don't believe there is straightforward way to do this mapping. See the answer to a similar question. I took a look at implementing each of the suggestions in this answer and, although they worked in some situations, they failed in others. Of course, I could have taken the wrong approach.

I have come to the conclusion that extracting and analyzing a bitmap extracted from the preview area and identifying those words that are completely enclosed by the red rectangle is the simplest. I circumscribe those words with their own red rectangle to show that they have been correctly identified.

The following is the reworked activity, a graphic overlay the produces the word boxes and the XML for the display. Comments are in the code. Good luck!

TestPhotoscan.kt

So what exactly is the problem here? Without knowing more about the application, I can't really tell why it's trying localhost first, but it seems like it's able to connect to mongo running on the person-db container after that based on these logs:

Finally I got the solution with the help of CronMaker.

So here is an attempt at helping.. For the most part, the docker compose yaml file is pretty close, with exception of some minor port and binding parameters. There is an expectation that initialization will be additional commands. Example:

1. docker-compose up the environment
2. run some scripts to init the environment

... but this was already part of the original post.

So here is a docker compose file

docker-compose.yml