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Questions tagged [lagom]

Lagom is a framework for creating microservice-based systems on the Java Virtual Machine.

Lagom is a framework for creating microservice-based systems. It offers four main features:

  • Service API
  • Persistence API
  • Development Environment
  • Production Environment

The Service API provides a way to declare and implement service interfaces, to be consumed by clients. For location transparency, clients discover services through a Service Locator. The Service API supports synchronous request-response calls as well as asynchronous streaming between services.

The Persistence API provides event-sourced persistent entities for services that store data. Command Query Responsibility Segregation (CQRS) read-side support is provided as well. Lagom manages the distribution of persisted entities across a cluster of nodes, enabling sharding and horizontal scaling. Cassandra is provided as a database out-of-the-box.

The Development Environment allows running all your services, and the supporting Lagom infrastructure, with one command. It hot-reloads your services when code changes; no fragile scripts are needed to set up and maintain a development environment. With Lagom, a developer can bring up a new service or join an existing Lagom development team in just a few minutes.

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Lagom: How to use topics without Event Sourcing

I am new to Lagom and I want to deal with Event Sourcing at some later point. So I'm not using the persistentEntityRegistry, instead I'm using a simple repository for CRUD operations. Anyway I would like to have the ability to notify other…
Ced
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How to make request param as optional in a rest api path in Lagom?

I want to make the request parameter optional in the path of the rest Call method. Suppose the service descriptor is public interface UserService extends Service { ServiceCall> getUsers(String filter); @Override …
konghoho
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UnresolvedUserTypeException: cannot resolve user type

I have a case class like this: case class Address(id String, location String) case class Person(id String, name String, address Option[Address]) Now I want to store these case class in cassandra table. I am working with Lagom Persistence. So I…
Akhil Vijayan
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Can we use Cassandra for managing persistent entity and MySQL for readside

Can I use Cassandra for storing persistent entity and MySQL for read-side database.
konghoho
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Need held with scala compile time error when defining a lagom service implementation

I've been using lagom with Java for some time without problems, but am struggling to get it to work with scala (disclosure - since I am fairly new to scala, I am probably doing something daft). I have defined a (very) minimal lagom service (below)…
rickturner646
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How should I model my Cassandra data for my Lagom service?

I am creating a service using Lagom framework and need some help in the architecture of the application. There is Employee service which contains information about all the employees. Each employee has an address. The models are like these, class…
konghoho
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Understanding Persistent Entities with streams of data

I want to use Lagom to build a data processing pipeline. The first step in this pipeline is a service using a Twitter client to supscribe to a stream of Twitter messages. For each new message I want to persist the message in Cassandra. What I dont…
user3139545
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Batch Insert in Lagom-Scala Cassandra readside

I searched on google but didn't got any links other than Cassandra read-side documentation page. So, I just want to ask if there's any API or function already included in Akka-Cassandra package for batch row inserting or I have to call the insert…
Ravinder Payal
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Error trying to inject a dependency in Lagom

I'm trying to create a simple service to send emails using Lagom framework and the Scaladsl. I'm trying to use the Play Mailer Plugin to handle emails but I'm struggling trying to inject it into the service implementation. I created the service…
Micho
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Generic Play json Formatter

I have a scala application and have a case class like - case class SR( systemId: Option[String] = None, x: Map[Timestamp, CaseClass1] = Map.empty, y: Map[Timestamp, CaseClass2] = Map.empty, y: Map[Timestamp, CaseClass3] = Map.empty ) Now…
Piyush_Rana
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Lagom with Spring

Lagom by default uses Google Guice as implementation od DI pattern. I would like to use Spring Framework instead. Is it possible? IF so, how should it be done? I have successfully integrated Akka with Spring (using hints from documentation and…
spam
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Why gen-idea stuck at 'lagom-internal-meta-project-cassandra' in lagom project

Could anyone please tell why while running sbt gen-idea with plugin 'addSbtPlugin("com.github.mpeltonen" % "sbt-idea" % "1.6.0")' stucks at creating the module 'lagom-internal-meta-project-cassandra'. [info] Creating IDEA module for project…
Pranjut
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unable to understand execution flow in lagom

I am following this tutorial - https://www.lagomframework.com/documentation/1.3.x/scala/ServiceImplementation.html I created a logged service //logged takes a ServerServiceCall as argument (serviceCall) and returns a ServerServiceCall. …
Manu Chadha
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unable to use 'call' method in lagom

I am experimenting with Lagom to check how call, pathCall and namedCall are invoked. I am following lagom's tutorial. I created a new service and opened url using following urls but I get error URL used (I expect to see hello2…
Manu Chadha
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Column family ID mismatch (found 52ac10b0-6e1b-11e7-82d3-c39cc53c1347; expected 42e51050-6e1b-11e7-82d3-c39cc53c1347)

am running the Lagom online-auction-java and am having the error , when running below when i execute sbt clean runAll ERROR [Native-Transport-Requests-13] 2017-07-21 16:52:45,704 ErrorMessage.java:384 - Unexpected exception during…
danielmwai
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