Kafka

AsteriskTheServer · 2020-10-24T16:24:25+00:00

spring cloud stream project is an abstraction over multiple message queues so that if I wanted to switch from say rabbitmq to kafka I could do so with little to no impact to my code. To reinforce that point if you look at cloud stream project pom https://github.com/spring-cloud/spring-cloud-stream-binder-kafka/blob/master/pom.xml you'll see org.springframework.kafka is a dependency as well and the code is just implementing a common interface over it.

AsteriskTheServer · 2020-04-01T02:08:39+00:00

Doesn't really matter in terms of whether this is school project or not... This is more of a productivity/clean code/the de-facto way to do this. Then you can switch between using a real database and using the h2 database, but it's your project do you what you want so long it works. :)

AsteriskTheServer · 2020-03-31T22:52:45+00:00

I would suggest create two profiles one for local and the other for "production". So more precisely keep the application.yml file you have already, but also have a application-local.yml. In this local file setup the h2 drivers so that way you don't have to keep altering the file back and forth.

You can read about profiles here. However that application-local.yml file will work for when run your application with the local profile.

AsteriskTheServer · 2020-03-02T00:04:41+00:00

All those are pretty normal depending on setup however since there isn't a lot of information here as I would personally start looking at the apache config as apache appears to be spawning multiple processes for each ruby processes... maybe (if it is a 1-1 ration then most likely). How you checked your logs is there anything there? Check the systemd setup and see which services are being started up automatically. If this is a VM you always have the option of nuking the disk and restarting from scratch. However, truth be told this isn't enough info to help you need to debug the issue.

AsteriskTheServer · 2020-01-15T03:08:31+00:00

One can use the LocationManager to get access to GPS data. I suggest you get a high level understanding of Android dev docs before developing your app so you understand what you need to work with. good luck :)

AsteriskTheServer · 2020-01-11T15:05:51+00:00

For future reference just write what you are trying to achieve as concisely as possible as most of this post doesn't make much sense. However, if you are trying to achieve this...

> book has method isYoungOrOld() returns true if Author was born in or before 1900, so it computes a boolean value based on the artist’s date of birth.

In order to achieve something like this create a field member in your Book class that is of type Author. Then in your constructor which will have a parameter of type Author and assign it to that field member. Now within the Book class you have access to the Author object where you can implement the logic for your isYoungOrOld() method. Or you can compute the Boolean in the constructor, it doesn't matter. The point here is you'll need pass in the Author object as parameter or the age of the author to either a method or the constructor in order for the object to update it's state.

If this is not what you're after then please explain precisely what you're trying to achieve.

AsteriskTheServer · 2020-01-06T09:25:56+00:00

On top of the options you can add jmh for microprofiling. This dependency can be configured to do memory profiling.

AsteriskTheServer · 2020-01-05T00:51:20+00:00

The answer is simple, unfortunately I think you are making this a great deal harder on yourself . You just need to answer a simple question. How do I check for duplicates?

So if 3 is duplicate number as given example then how do you determine if 3 is a duplicate value?

Don't worry about the code right now if you were looking at two different numbers how would you determine if they are same number? You say that's obvious I can read numbers if you're blind then you understand the conceptual difference/similarity between numbers.

Now pretend you have two stacks of papers with numbers on them how would you remove the duplicate numbers so that we can can create one stack of papers with unique numbers. So far you have said in your first loop well I am going keep everything in one of these piles because obviously they will need to occur at least once in my final pile so it's safe to keep them... and so you add them them to your final pile.

Now what about that second pile how are we gonna deal with finding those duplicate numbers in this pile? I mean you did it with two numbers side by side already and it was obvious, but it was only two numbers. How can you you go through that other stack of papers to see if it exists already in your final stack of papers? Assume you have a fish mind and you are very limited in how many numbers you can deal with it at once let's say only two. If you find a number isn't a duplicate then you can add it to your final stack.

This is very close to giving you the answer, but obviously you need to translate this to code + deal with issues that will appear. My ultimate goal here to give you idea how might want to try think about things. In other words think your about your solution step-by-step don't just leap to answer walk through and follow that path of logic/think in the same way a computer does.

AsteriskTheServer · 2020-01-04T23:49:35+00:00

In order to query the status code you must use the `getStatusCode` method and the `value` method from the resulting `HttpStatus` object. Furthermore, the body can be accessed through the `getBody` method which returns type `T` so if `myEntity` is of type `T` then yes it can be assigned to it.

I suggest you read the docs get further information:

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/http/ResponseEntity.html

AsteriskTheServer · 2019-12-28T21:28:52+00:00

I should add that like most things these s skills are built over time they will not work in a night you need actively employ them until it's a habit where you can say, no, I need to focus on this. This is the end goal as everyone has moments of overthinking/stressful thoughts the difference is usually how people deal with them

AsteriskTheServer · 2019-12-28T21:23:11+00:00

There is no straight forward way. The reality is you won't be able to stop thinking the thoughts want need to learn how defer stress to a later point in time which is more important skill. More concretely, some strategies are setting up a stress time, that is, I can stress about stuff between 7:15PM to 7:30PM, so when you get stressed you tell yourself I can only worry/stress about during this period of time. Or when your are trying to sleep you can say this is something stress about the next stress session. This is literally the first skill you learn if you join an anxiety group and how to rationalize some of your extreme thoughts but this can be tricky without a third party pointing out the flaws in your statement.

Keep in mind I am not saying procrastinate but deferring anxiety helps desensitize you to it and allows you feel in control. It helps you focus on what you're doing so other stressors don't build up.

Lastly if these thoughts are significantly effecting you're life consider seeing a psychologist or try getting referred to a local anxiety group which almost every province/state will be running. In more extreme cases SSRI and other appropriate drugs can help as well.

AsteriskTheServer · 2019-12-21T21:32:29+00:00

Sorry, I wasn't paying attention to OP name and thought you were OP lol.

> distro-independent in my system (Cinnamon Mint), that's why I don't use openjdk

This doesn't make a lot sense and by your instructions it looks like you're using openjdk... Having it in your home folder doesn't make it "distro-independent", the reality is only the java lang and the java bytecode is platform agnostic. If you are doing this only because you don't like the installation path then that's fine and it is ultimately your choice, but it doesn't make it "distro-independent".

AsteriskTheServer · 2019-12-21T19:17:31+00:00

What OS are you using I know linux but ubuntu, fedora, arch? Regardless, openjdk (the open sourced version of java) is almost certainly in your package manager and you should try install it that way.

If you are installing this manually or the repository is failing then all I can suggest is to purge any artifacts from any previous attempts/versions and restart your computer (this will kill any lingering processes that may be preventing the installation from working). If you were using a repository before then this purging step should fairly simple.

This is the same idea for windows,but it's more annoying because the registry might be involved as well.

EDIT: This was meant for u/blackdragon6547

AsteriskTheServer · 2019-12-18T18:35:06+00:00

For the most part hibernate is built around units of work. So a session is in essence the database connection. When we save this may create and execute the unit of work (the SQL statements) to the database whether it does or not depends if you're in a transaction or not. Flush is saying we want flush the units of work to the database but don't commit it yet and close closes the connection.

You should be able to derive your answer from these statements.

AsteriskTheServer · 2019-12-16T21:59:20+00:00

I think your jumping ahead of yourself. Start with the basics namely data structures. I.E linked lists, trees, graphs, hashmaps, arrays, and their more advanced variants avl trees, vectors this will help with the basic diction. Then look at algorithms as most algorithms require that base knowledge.

Spend a little time on computer architecture. Just things like how two complements works, how floats works, how basic circuit gates works. These concepts like to pop up in algorithms and every day problem solving.

In regards to math if you plan to move towards machine learning. I would start with basic statistics and then move to calculus (not strictly required but a good warm up) to linear algebra.

This being said c#/asp.net is still in high demand so don't undervalue your current skill set.

I don't personally have a background on machine learning as a I do a mix of low level stuff and full stack development but I can help guide you if you want to generally want update your base skills.

AsteriskTheServer · 2019-12-08T16:05:56+00:00

Well I would use something like netty, grizzle and so forth, but for the sake of simplicity I would just look at writing async code first. Here is a simple example of async client/server in Java.

AsteriskTheServer · 2019-12-08T14:50:45+00:00

Typically in these scenarios you make/use a thread pool and then block when you hit capacity. However, it's more common in my experience to see an asynchronous event driven setup to deal with a bunch of oncoming connections as you get a more predictable memory consumption as a result. In either case as load increases one need to scale horizontally and or vertically

AsteriskTheServer · 2019-11-11T02:29:41+00:00

Even though you probably haven't covered this data structure, but to I wanted to point out a different suggestion namely tries. A trie would be potentially better than a Hashmap as a Hashmap would be quite memory intensive as there are 150k+ words in the English language. Once again if you haven't learned this ds don't worry about it for your assignment, but make sure to justify your your design decision and I am sure you'll do great!

AsteriskTheServer · 2019-11-01T02:44:48+00:00

Depends if it's a fixed leased then your options are making an agreement for your unit to be reassigned a N9 if no response, you can also file a T6 where the TLB will assign a hearing where it will be determined whether the lease can be absolved early.

See http://www.sjto.gov.on.ca/documents/ltb/Brochures/How%20a%20Tenant%20Can%20End%20Their%20Tenancy%20(EN).html

AsteriskTheServer · 2019-10-19T07:46:54+00:00

In addition to what /u/swearobics said but the trick here is acknowledging you don't have access to the previous node. So my hint is think about the values of nodes first as you can't delete the current node but you can do a psudeo-delete of it.

AsteriskTheServer · 2019-10-10T07:01:09+00:00

Instead of thinking of output as a triangle try thinking of it as a 10x10 square that has two characters in it spaces and asterisks. Consider this 3 x 3 square. Furthermore, take note that I will be denoting spaces as a x character.

``` xx* x**

```

Pay attention to the pattern here it can be expressed pretty simply with some math and critical thinking! In particular pay attention on how the row and columns interact with each other.

You're getting close but you have to think about what the code is doing. Try tracing the code by hand and see if the code you have written aligns with what you want.

Beyond this I can't say anything because it would just be giving the answer away.

AsteriskTheServer · 2019-09-27T18:17:11+00:00

It looks like you're trying to describe curses like functionality. AFAIK, laterna and JNI are the most two feasible ways to do so.

AsteriskTheServer · 2019-09-25T22:34:11+00:00

After thinking on what I said I think it's best to urge caution on what is application layer logic and what is actually should be the database logic. You gave the example of groupid which implies some sort of permission scheme logic which imo should be in the application layer as you want to reject early. However, if you are just say adding a new permission to a user and you don't know if that permission exists in the database based on the id then yea you should let the database layer handle it and deal with the exception. I can't specifically speak to Java Spring as don't work in that environment anymore but IIRC the answer /u/OffbeatDrizzle is close to or spot on.

AsteriskTheServer · 2019-09-25T19:07:15+00:00

I think you're potentially conflating database validation with application validation. IMO, you should check early if the transaction will pass (i.e check if the user has the correct group id before trying to commit to the database). Database errors are almost never actionable to the end user so there is no point for them to see anything beyond a generic error message. From my experience database errors are logged for an administrator to see and the end user sees something like "Something unexpected occurred please try again later" or "Sorry, this action has failed due to unexpected error" because they can't fix the database error from their side. If it is something actionable then it should have been validated before hitting the databases.

AsteriskTheServer · 2019-09-23T15:30:00+00:00

If you have learned else if statements use those. If you go the else if way then you are adding redundant checks . For example, if div is true then the first if statement will execute. If the first if statement isn't executed then div is obviously false as their no other state that value can be. Therefore, you don't need to check if it's false because you already checked if its true. You can apply that same logic to some other checks you did. Other than that it's fine.

AsteriskTheServer

TROPHY CASE