we use in our backend AWS Aurora which has two instances, one for read+write-access and one only for read access.
In our backend we use Spring data JPA to manage our Entities in the database. Would it now be possible, that spring will use the read node for selecting data and the read/write node only for write operations?
How could we configure that? Therefore the read instance has another hostname this instance do nothing.
Thx.
Related
Usual org.springframework.data.redis.core.RedisTemplate have that multi() method, which allow to start a transaction and exec() to commit.
But org.springframework.data.redis.core.ReactiveRedisTemplate does not have that methods.
I searched a lot for an any way on how to use transaction with spring-boot-starter-data-redis-reactive and i found no solutions.
The only way i see it now is manualy create Lettuce Client Bean and use it along side Spring implementation. But that is not handy to have 2 separate redis clients.
Does anyone know how to use redis transaction with spring-boot-starter-data-redis-reactive? could you please write a simple example?
I have a Spring Boot application that uses MongoDB. My plan is to store data in a distributed caching system before it gets inserted into Mongo. If the database fails, the caching will have a queue and send to the DB once it is up. So, the plan is to make the caching layer in between the application and Mongo.
Can you suggest some ideas on how to implement this using Apache Ignite?
Take a look at write-behind cache store mode. It retries writing to the underlying database if insertion to the underlying DB fails. Let me know how it works for you.
You can also implement a custom CacheStore for an Ignite cache that will do the caching and enable write through for it. If the connection is lost, then you'll be able to collect entries in a buffer, while retrying to establish the connection back.
See more: https://apacheignite.readme.io/docs/3rd-party-store
Since I am trying hard to understand the microservice architecture pattern for some work, I came across the following question:
It's always said that a microservice usually has its own database. But does this mean that it always has to be on the same server or container (for example having one docker container that runs a MongoDB and my JAR)? Or can this also mean that on one server my JAR is running while my MongoDB is located somewhere else (so two containers for example)?
If the first one is correct (JAR and database within one container), how can I prevent that after some changes regarding my application and after a new deployment of my JAR my data of the MongoDB is resetted (since a whole new container is now running)?
Thanks a lot already :-)
Alternative opinion:
In 99% of real life cases you musnt have a single container that runs
database and the application, those should be separated, since one
(db) is keeping state, while the other (app) should be stateless.
You don't need a separate database for microservice, very often a separate schema is more than enough (e.g. you dont want to deploy a separate Exadata for each microservice :)). What is important is that only this microservice can read and write and make modifications to given tables others can operate on those tabls only through interfaces exposed by the microservice.
First of all each Microservice should have its own database.
Secondly it's not necessary and also not recommended to have the Microservice and its database on the same container.
Generally a single Microservice will have multiple deployments for scaling and they all connect to a single Database instance which should be a diff. container and if using things like NoSql DB's its a database cluster.
Yes, Each Microservice should have its own database and if any other Microservice needs data owned by another microservice, then they do it using an API exposed by Microservices. No, it's not at all necessary to have the Microservice and its database to be hosted on the same server. For Example - A Microservice can be hosted on-premise and its database can live in the cloud like AWS DynamoDB or RDS.
I'm writing an application that has to communicate across 3 different platforms. Two expose their DB via a REST API (no jdbc driver) and one is a native JDBC connection (ex: Derby, MySQL, Oracle, etc).
My problem is that I have no way of assuring any ACID'ity when updating data, given that the three should be updated at the same time.
I've tried reading up on Spring XA but it seems as both 2PC and 1PC require some form of transactional backends. Given that 2 of my 3 destinations are REST APIs, I don't have any transactions. Just a save/update option.
Are there techniques I can use to ensure that the 3 sources are synchronized and that I don't run into inconsistent states if ever a write fails (ie: REST endpoint unavialble, etc)?
A transaction example would be:
Read from DB
Write to REST-1 endpoint
Update DB
Write to REST-2 endpoint
Is there some form of XA I could employ to wrap everything in such a way I can be assured of consistency?
Is it possible to use transactions when Neo4j is used as standalone server? I am using functions from my Spring repositories, and probably each of them is executed as a separate transaction, but I would like to merge them into one. Is it possible to do this?
SDN doesn't support remote transactions (which only work with the transactional endpoint and Cypher) yet.
So the option you have to speed your operation up is to move the processing of the SDN entities into the server an expose a domain level REST API to your clients (either with Jersey, or SD-REST).
see: http://inserpio.wordpress.com/2014/04/30/extending-the-neo4j-server-with-spring-data-neo4j/